U.S. patent application number 14/998116 was filed with the patent office on 2017-06-29 for uplink interference management in shared spectrum networks.
The applicant listed for this patent is Intel Corporation. Invention is credited to Ying He, Beeshanga Jayawickrama, Markus Dominik Mueck, Srikathyayani Srikanteswara.
Application Number | 20170188314 14/998116 |
Document ID | / |
Family ID | 59088137 |
Filed Date | 2017-06-29 |
United States Patent
Application |
20170188314 |
Kind Code |
A1 |
Mueck; Markus Dominik ; et
al. |
June 29, 2017 |
Uplink interference management in shared spectrum networks
Abstract
A network control system for a first wireless network may
include a network control circuit configured to manage radio
communications of the first wireless network, where the network
control circuit is further configured to estimate a proximity to a
second wireless network for a plurality of user terminals based on
a measurement of the second wireless network reported by the
plurality of user terminals, determine whether the second wireless
network is experiencing excessive interference from the first
wireless network, and if the second wireless network is
experiencing excessive interference from the first wireless
network, adjust a transmit power allocation of one or more selected
user terminals of the plurality of user terminals based on the
estimated proximity to the second wireless network for the one or
more selected user terminals.
Inventors: |
Mueck; Markus Dominik;
(Unterhaching, DE) ; He; Ying; (Sydney, AU)
; Jayawickrama; Beeshanga; (Sydney, AU) ;
Srikanteswara; Srikathyayani; (Portland, OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intel Corporation |
Santa Clara |
CA |
US |
|
|
Family ID: |
59088137 |
Appl. No.: |
14/998116 |
Filed: |
December 24, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 52/243 20130101;
H04W 16/14 20130101; H04W 24/02 20130101; H04W 52/146 20130101 |
International
Class: |
H04W 52/24 20060101
H04W052/24; H04W 16/14 20060101 H04W016/14; H04W 52/14 20060101
H04W052/14; H04W 24/02 20060101 H04W024/02 |
Claims
1. A network control system for a shared spectrum first wireless
network comprising a network control circuit configured to manage
radio communications of a first wireless network, the network
control circuit further configured to: estimate a proximity to a
second wireless network for a plurality of user terminals based on
a measurement of the second wireless network reported by the
plurality of user terminals; wherein the plurality of user
terminals utilize a frequency band of the first wireless network
that is substantially similar to a frequency band of the second
wireless network; select one or more measurement terminals from the
plurality of user terminals based on the estimated proximity of the
plurality of user terminals; and receive one or more interference
measurements from the one or more measurement terminals that
indicate interference to the second wireless network related to the
first wireless network.
2. The network control system of claim 1, wherein the network
control circuit is configured to select one or more measurement
terminals from the plurality of user terminals based on the
estimated proximity of the plurality of user terminals by:
selecting one or more of the plurality of user terminals that
report the strongest measurements of the second wireless network as
the one or more measurement terminals.
3. The network control system of claim 1, wherein the network
control circuit is configured to estimate a proximity to a second
wireless network for a plurality of user terminals based on a
measurement of the second wireless network reported by the
plurality of user terminals by: determining that one or more first
user terminals of the plurality of user terminals that report
strong measurements are located closer to the second wireless
network than one or more second user terminals of the plurality of
user terminals that report weak measurements.
4. The network control system of claim 1, wherein the measurement
of the second wireless network reported by the plurality of user
terminals is a signal power measurement of the second wireless
network, and wherein the network control circuit is configured to
estimate a proximity to a second wireless network for a plurality
of user terminals based on a measurement of the second wireless
network reported by the plurality of user terminals by performing
at least one of: ranking the plurality of user terminals according
to the signal power measurement reported by the plurality of user
terminals; comparing a signal power measurement reported by a first
user terminal of the plurality of user terminals to a signal power
measurement reported by a second user terminal of the plurality of
user terminals; comparing the signal power measurement reported by
the plurality of user terminals to a signal power threshold; or
calculating an approximate proximity from the second wireless
network based on the signal power measurement.
5. The network control system of claim 1, wherein the network
control circuit is further configured to determine whether to
perform uplink power control based on the one or more interference
measurements.
6. The network control system of claim 5, wherein the network
control circuit is configured to determine whether to perform
uplink power control based on the one or more interference
measurements by: determining to perform uplink power control if the
one or more interference measurements indicate excessive
interference to the second wireless network.
7. The network control system of claim 6, wherein the network
control circuit is further configured to select one or more target
user terminals from the plurality of user terminals to reduce
allocated uplink transmit power based on the estimated proximity of
the one or more target user terminals from the second wireless
network.
8. The network control system of claim 5, wherein the network
control circuit is configured to determine whether to perform
uplink power control based on the one or more interference
measurements by: comparing the one or more interference
measurements to a predetermined interference threshold; and
determining to perform uplink power control if the one or more
interference measurements satisfy the predetermined interference
threshold.
9. The network control system of claim 1, wherein the measurement
of the second wireless network reported by a first user terminal of
the plurality of user terminals is a signal power measurement that
indicates a signal power of a signal received by the first user
terminal from the second wireless network.
10. A network control system for a shared spectrum wireless network
comprising a network control circuit configured to manage radio
communications of a first wireless network, the network control
circuit further configured to: estimate a proximity to a second
wireless network for a plurality of user terminals based on a
measurement of the second wireless network reported by the
plurality of user terminals; wherein the plurality of user
terminals utilize a frequency band of the first wireless network
that is substantially similar to a frequency band of the second
wireless network; determine whether the second wireless network is
experiencing excessive interference from the first wireless
network; and if the second wireless network is experiencing
excessive interference from the first wireless network, adjust a
transmit power allocation of one or more selected user terminals of
the plurality of user terminals based on the estimated proximity to
the second wireless network for the one or more selected user
terminals.
11. The network control system of claim 10, wherein the network
control circuit is further configured to select the one or more
selected user terminals from the plurality of user terminals based
on which of the plurality of user terminals have close estimated
proximities to the second wireless network.
12. The network control system of claim 10, wherein the network
control circuit is configured to adjust a transmit power allocation
of one or more selected user terminals of the plurality of user
terminals based on the estimated proximity to the second wireless
network for the one or more selected user terminals by: selecting
one or more user terminals of the plurality of user terminals that
have close estimated proximities to the second wireless network as
the one or more selected user terminals; and reducing the transmit
power allocation of the one or more selected user terminals.
13. The network control system of claim 10, wherein the network
control circuit is further configured to receive one or more
interference measurements from one or more measurement terminals,
and wherein the network control circuit is configured to determine
whether the second wireless network is experiencing excessive
interference from the first wireless network by: determining
whether the second wireless network is experiencing excessive
interference from the first wireless network based on the one or
more interference measurements.
14. The network control system of claim 13, wherein the network
control circuit is further configured to: select one or more
measurement terminals from the plurality of user terminals; and
receive one or more one or more interference measurements from one
or more measurement terminals, and wherein the network control
circuit is configured to determine whether the second wireless
network is experiencing excessive interference from the first
wireless network by: determining whether the second wireless
network is experiencing excessive interference from the first
wireless network based on the one or more interference
measurements.
15. The network control system of claim 14, wherein the network
control circuit is configured to select one or more measurement
terminals from the plurality of user terminals by: selecting the
one or more measurement terminals from the plurality of user
terminals based on the estimated proximity to the second wireless
network for the one or more measurement terminals.
16. The network control system of claim 10, wherein the network
control circuit is configured to adjust a transmit power allocation
of one or more selected user terminals of the plurality of user
terminals based on the estimated proximity to the second wireless
network for the one or more selected user terminals by: selecting
one or more user terminals of the plurality of user terminals that
report the strongest measurements of the second wireless network as
the one or more selected terminals; and reducing the transmit power
allocation of the one or more selected user terminals.
17. The network control system of claim 10, wherein the network
control circuit is configured to estimate a proximity to a second
wireless network for a plurality of user terminals based on a
measurement of the second wireless network reported by the
plurality of user terminals by: estimating the proximity to the
second wireless network for the plurality of user terminals
relative to the proximity of the other user terminals of the
plurality of user terminals to the second wireless network based on
the measurement of the second wireless network reported by the
plurality of user terminals.
18. The network control system of claim 10, wherein the first
wireless network is a licensee in a spectrum sharing system and the
second wireless network is an incumbent in the spectrum sharing
system.
19. The network control system of claim 18, wherein the spectrum
sharing system is a Licensed Shared Access (LSA) system or a
Spectrum Access System (SAS) system.
20. A mobile terminal comprising a radio processing circuit and a
baseband processing circuit configured to interact with the radio
processing circuit to transmit and receive radio signals, the
baseband processing circuit further configured to: receive a
composite signal comprising a first received signal from a first
wireless network and a second received signal from a second
wireless network; calculate a correlation between the composite
signal and a local reference signal to determine a signal power
measurement of the second received signal; report the signal power
measurement to the first wireless network as a measurement report;
and receive control signaling in response to the measurement report
that specifies an assigned operation configuration for the user
terminal.
21. The mobile terminal of claim 20, wherein the baseband
processing circuit is configured to receive control signaling in
response to the measurement report that specifies an operation
assignment for the user terminal by: receiving a measurement
operation assignment, the baseband processing circuit further
configured to: perform an interference measurement that indicates
interference to the second wireless network; and report the
interference measurement to the first wireless network.
22. The mobile terminal of claim 20, wherein the baseband
processing circuit is configured to receive control signaling in
response to the measurement report that specifies an operation
assignment for the user terminal by: receiving a transmit power
operation assignment that specifies a transmit power, the baseband
processing circuit further configured to: transmit signals
according to the transmit power.
23. The mobile terminal of claim 20, wherein the baseband
processing circuit is configured to calculate a correlation between
the composite signal and a local reference signal to determine a
signal power measurement of the second received signal by:
calculating a cross-correlation between the composite signal and
the local reference signal to obtain a reference signal channel
response; calculating a reference signal power measurement from the
reference signal channel response; and subtracting the reference
signal power measurement from a signal power measurement of the
composite signal to obtain the signal power measurement of the
second received signal.
24. The mobile terminal of claim 20, wherein the first received
signal comprises a downlink reference signal transmitted by a
transmission point of the first wireless network.
25. The mobile terminal of claim 20, wherein the first wireless
network is a licensee in a spectrum sharing system and the second
wireless network is an incumbent in the spectrum sharing system.
Description
TECHNICAL FIELD
[0001] Various embodiments relate generally to methods and devices
for uplink interference control in shared spectrum networks.
BACKGROUND
[0002] Recent developments in radio frequency licensing such as
spectrum sharing have introduced new possibilities for Mobile
Network Operators (MNOs). In particular, Licensed Spectrum Access
(LSA, proposed mainly for Europe in the 2.3-2.4 GHz bands) and
Spectrum Access System (SAS, proposed mainly in the U.S. for the
3.55-3.7 bands) may open up access to previously restricted
wireless frequency bands for mobile communications by allowing MNOs
to share certain spectrum bands with "incumbent" users.
[0003] While the frequency bands targeted by LSA and SAS may be
licensed and/or owned by incumbents (such as e.g. for government
use), the targeted frequency bands are relatively underutilized
over time and/or space. For example, incumbents may only rarely
utilize the targeted frequency bands, and/or may only employ the
targeted frequency bands in certain areas. Accordingly, both LSA
and SAS propose similar systems in which the targeted frequency
bands may be made available to cellular MNOs in scenarios, i.e.
temporally and/or geographically dependent, in which the incumbent
is not occupying the band. For example, one or more MNOs may be
granted access to the targeted frequency bands in scenarios where
the incumbent is not actively occupying the targeted frequency
bands in a particular geographic area. MNOs may thus utilize the
newly available bandwidth for mobile communications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] In the drawings, like reference characters generally refer
to the same parts throughout the different views. The drawings are
not necessarily to scale, emphasis instead generally being placed
upon illustrating the principles of the invention. In the following
description, various embodiments of the invention are described
with reference to the following drawings, in which:
[0005] FIG. 1 shows a network architecture for an LSA network;
[0006] FIG. 2 shows a network architecture for an SAS network;
[0007] FIG. 3 shows a first network scenario for a spectrum sharing
system;
[0008] FIG. 5 shows an internal configuration of a licensee base
station and a licensee user terminal;
[0009] FIG. 5 shows a second network scenario for a spectrum
sharing system;
[0010] FIG. 6 shows a method for selecting measurement terminals
and performing uplink power control;
[0011] FIG. 7 shows a method for performing signal power estimates
and interference measurement reporting;
[0012] FIG. 8 shows a message sequence chart illustrating
measurement terminal and uplink power control procedure;
[0013] FIG. 9 shows a method for obtaining interference
measurements;
[0014] FIG. 10 shows a method for performing transmission power
control; and
[0015] FIG. 11 shows a method for reporting measurements.
DESCRIPTION
[0016] The following detailed description refers to the
accompanying drawings that show, by way of illustration, specific
details and embodiments in which the invention may be
practiced.
[0017] The word "exemplary" is used herein to mean "serving as an
example, instance, or illustration". Any embodiment or design
described herein as "exemplary" is not necessarily to be construed
as preferred or advantageous over other embodiments or designs.
[0018] The words "plural" and "multiple" in the description and the
claims, if any, are used to expressly refer to a quantity greater
than one. Accordingly, any phrases explicitly invoking the
aforementioned words (e.g. "a plurality of [objects]", "multiple
[objects]") referring to a quantity of objects is intended to
expressly refer more than one of the said objects. The terms
"group", "set", "collection", "series", "sequence", "grouping",
"selection", etc., and the like in the description and in the
claims, if any, are used to refer to a quantity equal to or greater
than one, i.e. one or more. Accordingly, the phrases "a group of
[objects]", "a set of [objects]", "a collection of [objects]", "a
series of [objects]", "a sequence of [objects]", "a grouping of
[objects]", "a selection of [objects]", "[object] group", "[object]
set", "[object] collection", "[object] series", "[object]
sequence", "[object] grouping", "[object] selection", etc., used
herein in relation to a quantity of objects is intended to refer to
a quantity of one or more of said objects. It is appreciated that
unless directly referred to with an explicitly stated plural
quantity (e.g. "two [objects]", "three of the [objects]", "ten or
more [objects]", "at least four [objects]", etc.) or express use of
the words "plural", "multiple", or similar phrases, references to
quantities of objects are intended to refer to one or more of said
objects.
[0019] It is appreciated that any vector and/or matrix notation
utilized herein is exemplary in nature and is employed solely for
purposes of explanation. Accordingly, it is understood that the
approaches detailed in this disclosure are not limited to being
implemented solely using vectors and/or matrices, and that the
associated processes and computations may be equivalently performed
with respect to sets, sequences, groups, etc., of data,
observations, information, signals, etc. Furthermore, it is
appreciated that references to a "vector" may refer to a vector of
any size or orientation, e.g. including a 1.times.1 vector (e.g. a
scalar), a 1.times.M vector (e.g. a row vector), and an M.times.1
vector (e.g. a column vector). Similarly, it is appreciated that
references to a "matrix" may refer to matrix of any size or
orientation, e.g. including a 1.times.1 matrix (e.g. a scalar), a
1.times.M matrix (e.g. a row vector), and an M.times.1 matrix (e.g.
a column vector).
[0020] As used herein, a "circuit" may be understood as any kind of
logic implementing entity (analog or digital), which may be special
purpose circuitry or a processor executing software stored in a
memory, firmware, hardware, or any combination thereof.
Furthermore, a "circuit" may be a hard-wired logic circuit or a
programmable logic circuit such as a programmable processor, for
example a microprocessor (for example a Complex Instruction Set
Computer (CISC) processor or a Reduced Instruction Set Computer
(RISC) processor). A "circuit" may also be a processor executing
software, for example any kind of computer program, for example a
computer program using a virtual machine code such as for example
Java. Any other kind of implementation of the respective functions
which will be described in more detail below may also be understood
as a "circuit". It is understood that any two (or more) of the
described circuits may be combined into a single circuit with
substantially equivalent functionality, and conversely that any
single described circuit may be distributed into two (or more)
separate circuits with substantially equivalent functionality.
Accordingly it is understood that references to a "circuit" may
refer to two or more circuits that collectively form a single
circuit.
[0021] A "processing circuit" (or equivalently "processing
circuitry") as used herein is understood as referring to any
circuit that performs an operation on a signal or signals, such as
e.g. any circuit that performs processing on an electrical signal
or an optical signal. A processing circuit may thus refer to any
analog or digital circuitry that alters a characteristic or
property of an electrical or optical signal, which may include
analog and/or digital data. A processing circuit may thus refer to
an analog circuit (explicitly referred to as "analog processing
circuit(ry)"), digital circuit (explicitly referred to as "digital
processing circuit(ry)"), logic circuit, processor, microprocessor,
Central Processing Unit (CPU), Graphics Processing Unit (GPU),
Digital Signal Processor (DSP), Field Programmable Gate Array
(FPGA), integrated circuit, Application Specific Integrated Circuit
(ASIC), etc., or any combination thereof. Accordingly, a processing
circuit may refer to a circuit that performs processing on an
electrical or optical signal as hardware or as software, such as
software executed on hardware (e.g. a processor or microprocessor).
As utilized herein, "digital processing circuit(ry)" may refer to a
circuit implemented using digital logic that performs processing on
a signal, e.g. an electrical or optical signal, which may include
logic circuit(s), processor(s), scalar processor(s), vector
processor(s), microprocessor(s), controller(s), microcontroller(s),
Central Processing Unit(s) (CPU), Graphics Processing Unit(s)
(GPU), Digital Signal Processor(s) (DSP), Field Programmable Gate
Array(s) (FPGA), integrated circuit(s), Application Specific
Integrated Circuit(s) (ASIC), or any combination thereof.
Furthermore, it is understood that a single a processing circuit
may be equivalently split into two separate processing circuits,
and conversely that two separate processing circuits may be
combined into a single equivalent processing circuit.
[0022] As used herein, "memory" may be understood as an electrical
component in which data or information can be stored for retrieval.
References to "memory" included herein may thus be understood as
referring to volatile or non-volatile memory, including random
access memory (RAM), read-only memory (ROM), flash memory,
solid-state storage, magnetic tape, hard disk drive, optical drive,
etc., or any combination thereof. Furthermore, it is appreciated
that registers, shift registers, processor registers, data buffers,
etc., are also embraced herein by the term memory. It is
appreciated that a single component referred to as "memory" or "a
memory" may be composed of more than one different type of memory,
and thus may refer to a collective component comprising one or more
types of memory. It is readily understood that any single memory
component may be separated into multiple collectively equivalent
memory components, and vice versa. Furthermore, it is appreciated
that while memory may be depicted, such as in the drawings, as
separate from one or more other components, it is understood that
memory may be integrated within another component, such as on a
common integrated chip.
[0023] The term "base station" used in reference to an access point
of a mobile communication network may be understood as a macro base
station, micro base station, Node B, evolved NodeBs (eNB), Home
eNodeB, Remote Radio Head (RRH), relay point, etc.
[0024] As used herein, a "cell" in the context of
telecommunications may be understood as a sector served by a base
station. Accordingly, a cell may be a set of geographically
co-located antennas that correspond to a particular sectorization
of a base station. A base station may thus serve one or more cells
(or sectors), where each cell is characterized by a distinct
communication channel. Furthermore, the term "cell" may be utilized
to refer to any of a macrocell, microcell, femtocell, picocell,
etc.
[0025] The following description may detail exemplary scenarios
involving mobile device operating according to certain 3GPP (Third
Generation Partnership Project) specifications, notably Long Term
Evolution (LTE) and Long Term Evolution-Advanced (LTE-A). It is
understood that such exemplary scenarios are demonstrative in
nature, and accordingly may be similarly applied to other mobile
communication technologies and standards, such as any Cellular Wide
Area radio communication technology, which may include e.g. a 5th
Generation (5G) communication systems, a Global System for Mobile
Communications (GSM) radio communication technology, a General
Packet Radio Service (GPRS) radio communication technology, an
Enhanced Data Rates for GSM Evolution (EDGE) radio communication
technology, and/or a Third Generation Partnership Project (3GPP)
radio communication technology (e.g. UMTS (Universal Mobile
Telecommunications System), FOMA (Freedom of Multimedia Access),
3GPP LTE (Long Term Evolution), 3GPP LTE Advanced (Long Term
Evolution Advanced)), CDMA2000 (Code division multiple access
2000), CDPD (Cellular Digital Packet Data), Mobitex, 3G (Third
Generation), CSD (Circuit Switched Data), HSCSD (High-Speed
Circuit-Switched Data), UMTS (3G) (Universal Mobile
Telecommunications System (Third Generation)), W-CDMA (UMTS)
(Wideband Code Division Multiple Access (Universal Mobile
Telecommunications System)), HSPA (High Speed Packet Access), HSDPA
(High-Speed Downlink Packet Access), HSUPA (High-Speed Uplink
Packet Access), HSPA+ (High Speed Packet Access Plus), UMTS-TDD
(Universal Mobile Telecommunications System-Time-Division Duplex),
TD-CDMA (Time Division-Code Division Multiple Access), TD-CDMA
(Time Division-Synchronous Code Division Multiple Access), 3GPP
Rel. 8 (Pre-4G) (3rd Generation Partnership Project Release 8
(Pre-4th Generation)), 3GPP Rel. 9 (3rd Generation Partnership
Project Release 9), 3GPP Rel. 10 (3rd Generation Partnership
Project Release 10), 3GPP Rel. 11 (3rd Generation Partnership
Project Release 11), 3GPP Rel. 12 (3rd Generation Partnership
Project Release 12), 3GPP Rel. 13 (3rd Generation Partnership
Project Release 12), 3GPP Rel. 14 (3rd Generation Partnership
Project Release 12), 3GPP LTE Extra, LTE Licensed-Assisted Access
(LAA), UTRA (UMTS Terrestrial Radio Access), E-UTRA (Evolved UMTS
Terrestrial Radio Access), LTE Advanced (4G) (Long Term Evolution
Advanced (4th Generation)), cdmaOne (2G), CDMA2000 (3G) (Code
division multiple access 2000 (Third generation)), EV-DO
(Evolution-Data Optimized or Evolution-Data Only), AMPS (1G)
(Advanced Mobile Phone System (1st Generation)), TACS/ETACS (Total
Access Communication System/Extended Total Access Communication
System), D-AMPS (2G) (Digital AMPS (2nd Generation)), PTT
(Push-to-talk), MTS (Mobile Telephone System), IMTS (Improved
Mobile Telephone System), AMTS (Advanced Mobile Telephone System),
OLT (Norwegian for Offentlig Landmobil Telefoni, Public Land Mobile
Telephony), MTD (Swedish abbreviation for Mobiltelefonisystem D, or
Mobile telephony system D), Autotel/PALM (Public Automated Land
Mobile), ARP (Finnish for Autoradiopuhelin, "car radio phone"), NMT
(Nordic Mobile Telephony), Hicap (High capacity version of NTT
(Nippon Telegraph and Telephone)), CDPD (Cellular Digital Packet
Data), Mobitex, DataTAC, iDEN (Integrated Digital Enhanced
Network), PDC (Personal Digital Cellular), CSD (Circuit Switched
Data), PHS (Personal Handy-phone System), WiDEN (Wideband
Integrated Digital Enhanced Network), iBurst, Unlicensed Mobile
Access (UMA, also referred to as also referred to as 3GPP Generic
Access Network, or GAN standard)), Wireless Gigabit Alliance
(WiGig) standard, mmWave standards in general (wireless systems
operating at 10-90 GHz and above such as WiGig, IEEE 802.11ad, IEEE
802.11ay, etc.), etc. The examples provided herein are thus
understood as being applicable to various other mobile
communication technologies, both existing and not yet formulated,
particularly in cases where such mobile communication.
[0026] For purposes of this disclosure, radio communication
technologies may be classified as one of a Short Range radio
communication technology, Metropolitan Area System radio
communication technology, or Cellular Wide Area radio communication
technology. Short Range radio communication technologies include
Bluetooth, WLAN (e.g. according to any IEEE 802.11 standard), and
other similar radio communication technologies. Metropolitan Area
System radio communication technologies include Worldwide
Interoperability for Microwave Access (WiMax) (e.g. according to an
IEEE 802.16 radio communication standard, e.g. WiMax fixed or WiMax
mobile) and other similar radio communication technologies.
Cellular Wide Area radio communication technologies include GSM,
UMTS, LTE, LTE-Advanced (LTE-A), CDMA, WCDMA, LTE-A, General Packet
Radio Service (GPRS), Enhanced Data Rates for GSM Evolution (EDGE),
High Speed Packet Access (HSPA), HSPA Plus (HSPA+), and other
similar radio communication technologies.
[0027] The term "network" as utilized herein, e.g. in reference to
a communication network such as a mobile communication network, is
intended to encompass both an access component of a network (e.g. a
radio access network (RAN) component) and a core component of a
network (e.g. a core network component).
[0028] As utilized herein, the term "radio idle mode" or "radio
idle state" used in reference to a mobile terminal refers to a
radio control state in which the mobile terminal is not allocated
at least one dedicated communication channel of a mobile
communication network. The term "radio connected mode" or "radio
connected state" used in reference to a mobile terminal refers to a
radio control state in which the mobile terminal is allocated at
least one dedicated uplink communication channel of a mobile
communication network.
[0029] Unless explicitly specified, the terms "transmit" and "send"
encompass both direct and indirect transmission/sending. Similarly,
the term "receive" encompasses both direct and indirect reception
unless explicitly specified.
[0030] In spectrum sharing schemes such as Licensed Spectrum Access
(LSA, proposed mainly for Europe in the 2.3-2.4 GHz bands) and
Spectrum Access System (SAS, proposed mainly in the U.S. for the
3.55-3.7 bands), Mobile Network Operators (MNOs) may be granted
access to previously restricted radio frequency bands. Accordingly,
an SAS or LSA "licensee" may license certain targeted frequency
bands from "incumbents", and thus may be able to utilize the shared
frequency bands.
[0031] While the targeted frequency bands for LSA and SAS may
already be officially licensed and/or owned by the incumbents
(mainly related to government use), the targeted frequency bands
may be underutilized over time and/or space. For example, the
incumbents may utilize the targeted frequency bands relatively
rarely, and/or may employ the targeted frequency bands only in
certain areas. Accordingly, LSA and SAS propose a system in which
the targeted frequency bands may be made available to cellular MNOs
in scenarios (both geographically and temporally dependent) where
the incumbent is not occupying the band. For example, one or more
licensed MNOs may be granted access to the targeted frequency bands
in scenarios where the incumbent is not actively occupying the
targeted frequency bands, and accordingly may utilize the newly
available bandwidth for mobile communications.
[0032] As indicated above, LSA has identified the 2.3-2.4 GHz
frequency band (corresponding to 3GPP LTE Band 40) as a suitable
candidate for spectrum sharing, and has additionally been the focus
of proposals to also incorporate the 700 MHz and/or 3.6-3.8 GHz
bands. Under the proposed LSA framework, a licensee (e.g. an MNO or
any other entity that operates a wireless network) may operate a
3GPP LTE network on licensed shared basis, where an licensee may
engage in a multi-year sharing contract with an incumbent (such as
e.g. 10 years or more). As incumbents maintain prioritized access
of the targeted LSA band over all licensees, any licensee may be
required to vacate the targeted LSA band for a given geographic
area, given frequency range, and given period of time during which
an incumbent is accessing the targeted LSA band.
[0033] FIG. 1 shows block diagram 100 illustrating an LSA network
architecture. As shown in FIG. 1, LSA Spectrum Management relies on
a centralized LSA Repository. Incumbents may be required to provide
a-priori usage information to the database on the availability of
LSA spectrum on a time- and geographic-basis. Depending on the
indicated usage information, an LSA controller may employ control
mechanisms to grant/deny spectrum access to various licensed
incumbents and issue commands to vacate concerned bands. In this
operation operational approach, sensing mechanisms may not be
required to support the system for identification of incumbent
operation.
[0034] Similarly to LSA, proposed SAS arrangements may allow
licensees to operate a 3GPP LTE network on the 3.55-3.7 GHz
frequency band on a shared basis with an incumbent. However, as
opposed to the two-tier system between incumbent and licensee
(tier-2 and tier-2, respectively) in LSA, SAS additionally proposes
a third tier (tier-3) composed of General Authorized Access (GAA)
users. In this three-tier system, tier-2 users, or "Primary Access
License" (PAL) users, may only be allocated a limited portion of
the entire SAS band (e.g. the PAL spectrum with to 70 MHz
bandwidth) in the absence of an incumbent. The remaining spectrum,
in addition to any unused portions of the PAL spectrum, may be
allotted to GAA users which may typically employ the available
tier-3 spectrum for LTE Licensed Assisted Access (LSA) or WiFi-type
systems.
[0035] FIG. 2 shows block diagram 200 illustrating an SAS network
architecture. In contrast to LSA, SAS may be designed to ensure
coexistence between incumbent users that are not able to provide
any a-priori information to a centralized database. In the context
of SAS, incumbents may conventionally be military-related, and
accordingly SAS systems may provide an Environmental Sensing
Capability (ESC) to perform required sensing tasks. Spectrum access
decisions for tier-2 (PAL) and tier-3 (GAA) users may be based on
sensing results provided by an ESC.
[0036] Both LSA and SAS may additionally provide Quality of Service
(QOS) guarantees to licensees, where a licensee that is granted
access to a particular frequency band may be guaranteed a certain
QOS level. LSA and SAS also resolve congestion problems through
central coordination, such as preventing over-utilization of the
targeted frequency bands by incumbents and/or other MNOs at a given
time at a central control entity. As previously detailed regarding
FIGS. 1 and 2, LSA and SAS systems may employ an LSA controller and
SAS entity, respectively, to coordinate access between incumbents
and secondary users (e.g. registered licensees). Accordingly, these
central control entities may grant secondary users access to LSA
and SAS spectrum, which may be on an exclusive basis. Secondary
users may therefore enjoy dedicated access to the additional
spectrum available through LSA and SAS for a given period of time
and in a given geographic area.
[0037] As access to LSA and SAS spectrum may be situation-dependent
(i.e. time and geographic dependent), shared spectrum may be
appropriate for use in a "supplemental" role. For example, given
the variable availability of shared spectrum, it may be impractical
(albeit possible) in many scenarios to realize a comprehensive
wireless network entirely on shared spectrum. However, licensee
MNOs may be able to utilize dedicated licensed spectrum (i.e.
exclusively licensed by a licensee) in a primary role while
allocating shared spectrum for supplemental uplink and/or downlink.
Licensee MNOs may thus be able to rely on the constant availability
of dedicated licensed spectrum while utilizing shared spectrum to
increase bandwidth when the shared spectrum is available.
[0038] Accordingly, shared spectrum may be useful in carrier
aggregation schemes, which may commonly have a "primary" carrier
and one or more "secondary" carriers. Accordingly, licensees may
use shared spectrum for secondary carriers to complement the
primary carriers composed of dedicated licensed spectrum. Licensees
may employ shared spectrum in this manner in either a supplemental
downlink (SDL) or supplemental uplink (SUL) role, and may even be
able to adjust the relative balance of shared spectrum for SDL and
SUL, such as by allocating a greater number of either uplink frames
or downlink frames in a Time Division Duplexing (TDD) system or by
allocating more of the shared spectrum bandwidth to either uplink
or downlink in a Frequency Division Duplexing (FDD) system.
[0039] Many of the bands identified by the proposed LSA and SAS
systems for European and American systems are employed in other
regions as TDD bands for Third Generation Partnership Project
(3GPP) networks. Accordingly, many Original Equipment Manufacturers
(OEM) may already manufacture handsets configured to utilize the
LSA and SAS spectrum for 3GPP TDD networks. Accordingly, it may be
relatively straightforward for OEMs to enable manufactured handsets
to additionally use the LSA and SAS bands for 3GPP TDD in other
regions where the LSA and SAS bands were previously unavailable due
to wireless frequency licensing restrictions. Regardless, shared
spectrum may be utilized for any type of wireless network and thus
are not limited to TDD-only use.
[0040] Accordingly, spectrum sharing systems may provide more
bandwidth available for licensee use. However, even when granted
access to shared spectrum by an incumbent, licensees may need to
carefully monitor licensee radio activity in order to make sure
incumbents are protected. As previously indicated, shared spectrum
grants may be geographically-dependent, and a licensee may
therefore be granted access to shared spectrum in a first
geographical area while an incumbent maintains access to the same
shared spectrum in a neighboring second geographical area. In order
to effectively manage interference to the incumbent, spectrum
sharing schemes may define geographical zones that place certain
limitations on licensee radio activity in order to ensure that
incumbents do not suffer from excessive interference.
[0041] For example, the current LSA proposal has specified three
"zones": exclusion zones, restriction zones, and protection zones.
An exclusion zone is specified as a geographical area within which
LSA Licensees are not permitted to have active radio transmitters
using the particular shared spectrum. Accordingly, incumbent cells
may cated within such exclusion zones (although not exclusively
limited to such), and licensee transmitters may therefore not be
permitted to actively transmit using shared spectrum in order to
prevent interference on the incumbent. Restriction zones are
defined as geographical areas within which LSA Licensees are only
allowed to operate radio transmitters according to certain
restrictive conditions, such as maximum equivalent isotropically
radiated power (EIRP) limits and/or constraints on antenna
parameters. Lastly, protection zones are defined as geographical
areas within which incumbent receives will not be subject to
harmful interference caused by LSA Licensee transmissions, e.g.
where the mean field strength does not exceed a defined value in
dB.mu.V/m/MHz.
[0042] SAS may employ similar designations of zones, where
exclusion zones are equivalently defined as areas in which
licensees may not have active radio transmitters operating on
shared spectrum. SAS may similarly designate protection zones in
which licensee operation must be protected; however, SAS may not
utilize explicit restrictions based on mean field strength to
define such protection. Regardless, protection of SAS incumbents in
SAS protection zones may be treated similarly to protection of LSA
incumbents in LSA protection zones, where interference is managed
based on constraining the interference to the incumbent caused by a
licensee to remain below certain levels.
[0043] Protection zones in both SAS and LSA may be of particular
interest, as licensee transmitters may be allowed to utilize shared
spectrum as long as the incumbent is sufficiently protected, which
may as detailed above include ensuring that the aggregate
interference to the incumbent caused by a licensee is below certain
threshold levels. Licensees may therefore need to be able to
accurately estimate current levels of interference to the incumbent
as well as be able to employ effective transmit power control
measures to reduce interference if necessary.
[0044] In a mobile communication context, it may be the
responsibility of licensee base stations to evaluate the current
levels of interference on an incumbent as well perform uplink
and/or downlink power control if excessive interference levels are
detected. While downlink transmissions by a licensee base station
may cause some interference to an incumbent cell, downlink
interference may be relatively limited due to the remote location
of base stations relative to incumbent cells. Uplink transmissions
by licensee user terminals on shared spectrum may however be more
problematic as mobile terminals may venture proximate to or even
into incumbent cells. Accordingly, licensee base stations may need
to more thoroughly monitor uplink transmissions in order to ensure
that interference to incumbents remains within the acceptable
levels.
[0045] For example, a licensee base station may operate a
conventional mobile communication system on licensed spectrum, and
accordingly may be serving a number of mobile terminals.
Additionally, the licensee base station may have been granted
access to shared spectrum e.g. in an LSA or SAS context, and as a
result may be able to utilize the shared spectrum for downlink
and/or uplink. Although the licensee base station may primarily
utilize shared spectrum for supplemental purposes, e.g. SDL and/or
SUL, licensee base stations may alternatively utilize shared
spectrum in a primary downlink and/or uplink role.
[0046] The licensee base station may be located proximate to an
incumbent cell that is actively utilizing the same shared spectrum,
such as in a protection zone. The licensee base station may
therefore need to monitor and regulate interference caused to the
incumbent by both downlink transmissions by the licensee base
station and uplink transmissions by the served mobile terminals on
the shared spectrum. Focusing on an uplink context, the licensee
base station may need to perform uplink power control in order to
ensure that uplink transmissions by the served mobile terminals do
not result in excessive interference to the incumbent. The licensee
base station may also need to ensure that uplink transmissions on
shared spectrum by the served mobile terminals are detectable by
the base station, and accordingly may need to balance the shared
spectrum uplink allocation of the served mobile terminals to ensure
that incumbents are protected as well as that uplink transmissions
are detectable at the licensee base station.
[0047] As previously indicated, interference to incumbents on
shared spectrum may be restricted according to predetermined
thresholds or similar interference level criteria in protection
zones. The licensee base station may thus need to evaluate the
level of interference experienced by the incumbent cell in order to
regulate uplink transmit power such that interference to the
incumbent remains at or within the acceptable levels. Such may
include both obtaining uplink interference estimates and executing
uplink power control for licensee user terminals based on the
obtained uplink interference measurements.
[0048] Licensee base stations may conventionally evaluate uplink
interference to the incumbent by analyzing measurements provided by
various licensee user terminals served by the licensee base
station. For example, a licensee base station may assign licensee
user terminals to measure uplink interference caused by the
remaining licensee user terminals, and may consequently estimate
the level of interference experienced by the incumbent cell in
order to determine whether the current level of interference is
acceptable or not.
[0049] If a licensee base station determines that the level of
uplink interference to the incumbent is too high, e.g. above a
predefined threshold, the licensee base station may execute uplink
power control measures in order to reduce the uplink interference
to within the permitted levels. Specifically, licensee base
stations may select one or more licensee user terminals to prohibit
from using shared spectrum for uplink and/or by reducing the
permitted uplink transmit power for one or more licensee user
terminals.
[0050] As the licensee may employ the shared spectrum in a
supplemental uplink role (e.g. SUL), the restricted licensee user
terminals may still be free to perform uplink activity on dedicated
licensed spectrum, i.e. on a conventional mobile communication
system operated by the licensee on dedicated licensed spectrum.
Furthermore, assuming downlink interference to the incumbent
remains tolerable, the restricted mobile terminals may still be
able to utilize the shared spectrum in an SDL capacity. Licensee
base stations may employ varying levels of such power control,
which may include restricting some mobile terminals to only SDL as
detailed above, restricting all mobile terminals to only SDL (which
may include allocating all shared spectrum in time and frequency to
downlink, e.g. for either a TDD or FDD context), or by restricting
the SUL transmit powers of certain or all mobile terminals to
reduced levels. It is again noted that shared spectrum may not be
limited to only supplemental roles, and accordingly MNOs may
operate a comprehensive wireless system (uplink and/or downlink) in
a primary role on shared spectrum.
[0051] While performing such uplink power control may predictably
reduce uplink interference to the incumbent, a random or arbitrary
selection of licensee user terminals for power control may not be
particularly efficient. For example, due to the dispersed
distribution of licensee user terminals, certain licensee user
terminals may be located relatively close to the incumbent cell
while other licensee user terminals situated on the opposite edge
of the coverage area of the licensee base station may be located
far from the incumbent cell. Accordingly, the licensee user
terminals proximate to the incumbent cell may contribute
appreciably higher levels of interference to the incumbent while
distant licensee user terminals may cause relatively low level of
interference. As a result, arbitrary (e.g. selecting certain
licensee user terminals to restrict from shared spectrum uplink or
selecting certain licensee user terminals to allot reduced shared
spectrum uplink transmit power) or uniform (e.g. prohibiting shared
spectrum uplink for all licensee user terminals or reducing shared
spectrum uplink transmit power for all license user terminals)
application of power control procedures to all licensee user
terminals may not be optimal. For example, reducing uplink transmit
power allowances for licensee user terminals located far from the
incumbent may not be productive, as such licensee user terminals
may only contribute minimally to the interference seen by the
incumbent. Randomly selecting licensee user terminals to restrict
uplink transmissions for and/or applying uniform power control to
all licensee user terminals may thus not be optimal in terms of
managing uplink interference to incumbents.
[0052] Furthermore, licensee base stations may need accurate uplink
interference estimations in order to decide whether to perform
uplink power control. For example, inaccurate interference
measurements may result in either unnecessary power control (e.g.
if interference measurements are too high) or in excessive
unmitigated interference to the incumbent (e.g. if interference
measurements are too low). As previously indicated, licensee base
stations may rely on mobile terminals to perform and report radio
measurements back to the licensee base station for evaluation.
[0053] Accordingly, efficient licensee uplink operation on shared
spectrum in protection zones may include both accurate interference
measurements and effective application of power control
procedures.
[0054] Furthermore, it is noted that the uplink interference
estimation and power control procedures detailed herein are not
limited to shared spectrum schemes such as LSA and SAS. For
example, the uplink interference estimation and power control
procedures may be equivalently employed by any entity that operates
a wireless network in proximity to another entity on common
frequency bands, which may or may not directly overlap (e.g. may
utilize adjacent frequency bands that cause leakage interference
onto one another). For example, spectrum licensing in the United
States may allow for a first MNO and second MNO to utilize the same
frequency band in adjacent geographical areas. As a result, uplink
transmissions by the first MNO may cause interference to the second
MNO, such as if user terminals of the first MNO are located close
to or within the coverage area of the second MNO. Accordingly, the
first MNO may implement uplink interference estimation and power
control procedures in order to manage interference to the second
MNO. Furthermore, SAS schemes may even shared the same frequency
bands between an incumbent and more than one MNO, such as where a
first MNO licenses a shared spectrum band from an incumbent in a
first geographical region and a second MNO licenses that same
shared spectrum band from the same incumbent in a second
geographical region. Accordingly, the first MNO and second MNO may
need to consider interference to the incumbent as well as to the
other MNO. Many such scenarios are possible and thus recognized as
applicable in the context of this disclosure.
[0055] FIG. 3 shows an exemplary wireless network 300 composed of
licensee base station 310 and incumbent base station 320. It is
understood that the scenario depicted in FIG. 3 is exemplary, and
may vary dependent on the particular network architectures employed
by both licensee base station 310 and incumbent base station 320.
Wireless network 300 may be a shared spectrum network such as an
SAS or LSA network. As noted above, wireless network 300 may
alternatively be any wireless network in which radio activity of
the licensee interferes with radio activity of the incumbent.
[0056] FIG. 4 shows a block diagram illustrating the various
components of licensee base station 310 and licensee user terminal
400. As shown in FIG. 4, licensee base station 310 may include
antenna system 312, radio processing circuit 314, baseband
processing circuit 316, and uplink control circuit 318. Licensee
base station 310 may receive wireless radio frequency signals with
antenna system 312, which may each be a single antenna or an
antenna array composed of multiple antennas. Antenna system 312 may
transduce received wireless radio frequency signals into electrical
radio frequency signals and provide resulting electrical radio
frequency signals to radio processing circuit 314.
[0057] Radio processing circuit 314 may be configured as a Remote
Radio Unit (RRU) in a base station context, and thus may be
configured to transmit and receive wireless signals. Radio
processing circuit 314 may include various reception circuitry
components, which may include analog circuitry configured to
process electrical radio frequency signals such as e.g. mixing
circuitry to convert received electrical radio frequency signals to
baseband and/or intermediate frequencies. Radio processing circuit
314 may also include amplification circuitry to amplify received
electrical radio frequency signals, such as power amplifiers (PAs)
and/or Low Noise Amplifiers (LNAs). Radio processing circuit 314
may additionally include various transmission circuitry components
configured to transmit internally received signals, such as e.g.
baseband and/or intermediate frequency signals provided by baseband
processing circuit 316, which may include mixing circuitry to
modulate internally received signals onto one or more radio
frequency carrier waves and/or amplification circuitry to amplify
internally received signals before transmission. Radio processing
circuit 314 may provide such signals to antenna system 312 for
wireless transmission.
[0058] Baseband processing circuit 316 may be configured as a
Baseband Unit (BBU) in a base station context, and may be
responsible for controlling radio communications according to a
wireless communication protocol, e.g. LTE, UMTS, LTE, CDMA, etc.
Baseband processing circuit 316 may be a processing circuit such as
a Central Processing Unit (CPU), microprocessor (i.e. a single chip
implementation of a CPU), or a microcontroller (i.e. a single chip
implementation of a CPU, memory (e.g. ROM or RAM), and other
peripherals) configured to execute program code that defines
arithmetic, logical, control and input/output (I/O) processor
operations. Baseband processing circuit 316 may be configured to
control operation of radio processing circuit 314 and antenna
system 312 in accordance with a wireless communication protocol
stack by executing program code of software and/or firmware modules
of a wireless communication protocol stack. Although not explicitly
depicted in FIG. 3, baseband processing circuit 316 may include one
or more memory components. Baseband processing circuit 316 may
retrieve the corresponding program code from the one or more
provided memory components and execute the program code of the
software and/or firmware modules to control radio processing
circuit 314 in accordance with control logic provided by various
layers of the wireless communication protocol stack, which may
include controlling physical (PHY) layer circuitry included as part
of baseband processing circuit 316 in order to transmit and receive
wireless communication signals with radio processing circuit 314
and antenna system 312. Further references herein to reception
and/or transmission of wireless signals and other processing
operations by licensee base station 310 may thus be understood as
an interaction between antenna system 312, radio processing circuit
314, and baseband processing circuit 316 as detailed above.
[0059] Uplink control circuit 318 may be configured to manage
uplink transmissions by licensee user terminals served by licensee
base station 310, and accordingly may be configured to interact
with baseband processing circuit 310 in order to communicate with
licensee user terminals via control signaling in order to both
allocate uplink transmission resources. Uplink control circuit 318
may be a processing circuit such as a CPU, microprocessor (i.e. a
single chip implementation of a CPU), or a microcontroller (i.e. a
single chip implementation of a CPU, memory (e.g. ROM or RAM), and
other peripherals) configured to execute program code that defines
arithmetic, logical, control and input/output (I/O) processor
operations. Uplink control circuit 318 may be configured to control
uplink communications according to a wireless communication
protocol, e.g. LTE, UMTS, LTE, CDMA, etc., and accordingly may be
configured to control operation of.
[0060] Although not explicitly depicted in FIG. 3, uplink control
circuit 318 may include one or more memory components. Uplink
control circuit 318 may retrieve the corresponding program code
from the one or more provided memory components and execute the
program code of the software and/or firmware modules to control
perform uplink transmission control procedures in accordance with
control logic provided by various layers of the wireless
communication protocol stack, which may include evaluating radio
measurements, selecting licensee user terminals for certain roles,
allocating uplink transmission resources to licensee user terminals
(for both shared spectrum and licensed dedicated spectrum),
instructing baseband processing circuit 316 to provide control
signaling to licensee user terminals, etc. The functionality of
uplink control circuit 318 detailed herein may be embodied as
computer-readable instructions or code and stored in a
non-transitory computer-readable storage medium for execution by
uplink control circuit 318. Uplink control circuit 318 may be
included as a component of baseband processing circuit 316 (e.g. in
a BBU), as a component of radio processing circuit 312 (e.g. in an
RRU), separately within licensee base station 310, as part of the
core network connected to licensee base station 310, or as a radio
access network entity connected to multiple licensee base
stations.
[0061] As will be further detailed, in a first aspect of the
disclosure uplink control circuit 318 may be a network control
circuit configured to manage radio communications for a first
wireless network (the licensee network), and may be further
configured to estimate a proximity to a second wireless network for
each of a plurality of user terminals based on a measurement of the
second wireless network reported by each of the plurality of user
terminals, select one or more measurement terminals from the
plurality of user terminals based on the estimated proximity of
each of the plurality of user terminals, and receive one or more
interference measurements from the one or more measurement
terminals that indicate interference to the second wireless network
caused by the first wireless network. In a second aspect of the
disclosure, uplink control circuit 318 may be a network control
circuit configured to manage radio communications for a first
wireless network (the licensee network), and may be further
configured to estimate a proximity to a second wireless network for
each of a plurality of user terminals based on a measurement of the
second wireless network reported by each of the plurality of user
terminals, determine whether the second wireless network is
experiencing excessive interference from the first wireless
network, and if the second wireless network is experiencing
excessive interference from the first wireless network, adjust a
transmit power allocation of one or more selected user terminals of
the plurality of user terminals based on the estimated proximity to
the second wireless network for each of the one or more selected
user terminals.
[0062] Accordingly, licensee base station 310 may additionally be
connected with a core network, and accordingly may act as an
interface between the radio access network portion and the core
network portion of the licensee communication network.
[0063] Licensee user terminal 410 may be configured as a
counterpart device to licensee base station 310. As shown in FIG.
4, licensee user terminal 410 may include antenna system 412, radio
processing circuit 414, and baseband processing circuit 416.
Licensee base station 410 may receive wireless radio frequency
signals with antenna system 412, which may each be a single antenna
or an antenna array composed of multiple antennas. Antenna system
412 may transduce received wireless radio frequency signals into
electrical radio frequency signals and provide resulting electrical
radio frequency signals to radio processing circuit 414.
[0064] Radio processing circuit 414 may be configured as a mobile
terminal radio frequency (RF) transceiver, and thus may be
configured to transmit and receive wireless signals. Radio
processing circuit 414 may include various reception circuitry
components, which may include analog circuitry configured to
process electrical radio frequency signals such as e.g. mixing
circuitry to convert received electrical radio frequency signals to
baseband and/or intermediate frequencies. Radio processing circuit
414 may also include amplification circuitry to amplify received
electrical radio frequency signals, such as power amplifiers (PAs)
and/or Low Noise Amplifiers (LNAs). Radio processing circuit 414
may additionally include various transmission circuitry components
configured to transmit internally received signals, such as e.g.
baseband and/or intermediate frequency signals provided by baseband
processing circuit 416, which may include mixing circuitry to
modulate internally received signals onto one or more radio
frequency carrier waves and/or amplification circuitry to amplify
internally received signals before transmission. Radio processing
circuit 414 may provide such signals to antenna system 412 for
wireless transmission.
[0065] Baseband processing circuit 416 may be configured as a
baseband modem, and may be responsible for controlling radio
communications according to a wireless communication protocol, e.g.
LTE, UMTS, LTE, CDMA, etc. Baseband processing circuit 416 may be a
Central Processing Unit (CPU) such as a microprocessor (i.e. a
single chip implementation of a CPU) or a microcontroller (i.e. a
single chip implementation of a CPU, memory (e.g. ROM or RAM), and
other peripherals) configured to execute program code that defines
instructions for arithmetic, logical, control and input/output
(I/O) processor operations. Baseband processing circuit 416 may be
configured to control operation of radio processing circuit 414 and
antenna system 412 in accordance with a wireless communication
protocol stack by executing program code of software and/or
firmware modules of a wireless communication protocol stack.
Although not explicitly depicted in FIG. 3, baseband processing
circuit 416 may include one or more memory components. Baseband
processing circuit 416 may retrieve the corresponding program code
from the one or more provided memory components and execute the
program code of the software and/or firmware modules to control and
radio processing circuit 414 in accordance with control logic
provided by various layers of the wireless communication protocol
stack, such as Layer 3, Layer 2, and Layer 1 (PHY layer) control
logic, which may include controlling PHY layer circuitry included
in baseband processing circuit 416 in order to transmit and receive
wireless communication signals with radio processing circuit 414
and antenna system 412. The functionality of baseband processing
circuit 416 detailed herein may be embodied as computer-readable
instructions or code and stored in a non-transitory
computer-readable storage medium for execution by baseband
processing circuit 416. Further references herein to reception
and/or transmission of wireless signals and other processing
operations by licensee user terminal 410 may thus be understood as
an interaction between antenna system 412, radio processing circuit
414, and baseband processing circuit 416 as detailed above.
[0066] As will be detailed, licensee user terminal 410 may be a
mobile terminal comprising a radio processing circuit (radio
processing circuit 414) and a baseband processing circuit (baseband
processing circuit 414) configured to interact with the radio
processing circuit to transmit and receive radio signals, where the
baseband processing circuit is further configured to receive a
composite signal including a first received signal from a first
wireless network and a second received signal from a second
wireless network, calculate a correlation between the composite
signal and a local reference signal to determine a signal power
measurement of the second received signal, report the signal power
measurement to the first wireless network as a measurement report,
and receive control signaling in response to the measurement report
that specifies an assigned operation configuration for the user
terminal.
[0067] Licensee base station 310 may be configured to communicate
with licensee user terminal 410 over wireless channel 420, where
the communication connection may be controlled by baseband
processing circuits 316 and 416 according to a particular radio
access technology protocol. As depicted in FIG. 3, licensee base
station 310 may communicate with multiple licensee user terminals,
which may configured equivalently to licensee user terminal
410.
[0068] Incumbent base station 320 may operate a wireless network on
spectrum that is licensed by an incumbent operator. Licensee base
station 310 may correspond to an MNO or other licensee that
licenses the shared spectrum from the incumbent operator according
to a spectrum sharing system, which may include licensing the
shared spectrum on a time- and geographic-dependent basis.
Incumbent base station 320 may serve a corresponding incumbent cell
(not explicitly depicted in FIG. 3) while licensee base station 310
may serve a corresponding licensee cell (not explicitly depicted in
FIG). Each of incumbent base station 320 and licensee base station
310 may each serve one or more users located within the respective
incumbent and licensee cells.
[0069] The licensee may thus operate a mobile communication network
such as an LTE network using the shared spectrum. Although not
limited to such, the licensee may utilize the available shared
spectrum in a supplemental role, such as by allowing mobile
terminals to utilize the shared spectrum for SUL or SDL purposes.
Accordingly, licensee base station 310 (or another proximate base
station of the licensee operator) may additionally operate a
separate mobile communication network on dedicated spectrum that is
exclusively licensed to the licensee operator. Accordingly,
licensee user terminals served by licensee base station 310 may
utilize both licensed spectrum in a primary role in addition to the
shared spectrum in a secondary or supplemental role.
[0070] As previously detailed, spectrum sharing systems may
designate certain geographic areas in which licensee operation is
restricted (which may also be time-dependent restrictions).
Accordingly, the area surrounding incumbent base station 320 may be
designated as an exclusion zone (which may include and even extend
past the incumbent cell boundaries) where the licensee operator is
not allowed to actively operate radio transmitters on shared
spectrum. Downlink transmissions by licensee base station 310 may
not cause substantial interference due to the distance relative to
the incumbent cell; however, licensee base station 310 may thus
need to ensure that licensee user terminals do not perform uplink
transmissions on shared spectrum within the exclusion zone. It is
again noted that while uplink transmissions on shared spectrum may
be prohibited (e.g. SUL), licensee user terminals may be free to
perform uplink transmissions on licensed spectrum.
[0071] Licensee base station 310 may be located within a protection
zone or another similar interference restriction zone, where
incumbent receivers will not be subject to harmful interference
caused by licensee transmissions on shared spectrum. While downlink
transmissions by licensee base station 310 may not be significantly
problematic, excessive uplink transmissions by licensee user
terminals, in particular licensee user terminals located proximate
to the incumbent cell, may result in excessive interference to
incumbent users. Accordingly, licensee base station 310
(specifically uplink control circuit 318) may be responsible for
managing uplink licensee user terminal activity in order to ensure
that incumbent base station 320 and the corresponding incumbent
users are protected.
[0072] As previously indicated, it may be important for licensee
base station 310 to consider at least two factors in order to
ensure protection of incumbent users with respect to licensee
activity in protection zones: accurate estimation of interference
to the incumbent and appropriate power control measures for
licensee activity if excessive interference is detected.
[0073] Regarding power control measures for licensee activity,
licensee base station 310 may permit certain licensee user
terminals to utilize the shared spectrum for uplink transmission.
However, licensee activity may substantially interfere with
incumbent operation if licensee base station 310 does not carefully
consider both which licensee user terminals are allowed to utilize
shared spectrum for uplink and the uplink transmission power
utilized by such licensee user terminals.
[0074] In the exemplary scenario of FIG. 3, licensee base station
310 may allow a random or "arbitrary" selection of licensee user
terminals to utilize the shared spectrum for uplink, which may
result in a wide distribution of licensee shared spectrum uplink
user terminals across the licensee cell and protection zone.
Additionally and/or alternatively, licensee base station 310 may
allow each licensee user terminal that wishes to transmit uplink
data (e.g. by requesting uplink resources from licensee base
station 310 via control signaling) to utilize shared spectrum,
which may potentially also result in a "random" distribution of
licensee terminals utilizing shared spectrum for uplink. Such
licensee shared spectrum uplink user terminals may optionally
utilize the shared spectrum for downlink in addition to uplink, or
alternatively may solely utilize dedicated licensed spectrum for
downlink.
[0075] However, as a result of the random selection of licensee
shared spectrum uplink user terminals, some of the licensee shared
spectrum uplink user terminals may be located closer to the
incumbent cell (and exclusion zone) than other licensee shared
spectrum uplink user terminals, and may even be located within the
exclusion zone. Such close proximity to the incumbent cell may
result in substantial interference to incumbent operation. As
denoted by the uplink interference shading in FIG. 3, incumbent
receivers located closest to the licensee cell (and consequently
located closest to licensee shared spectrum uplink user terminals)
may suffer from significant interference as a result of the
licensee shared spectrum uplink activity. While the interference
experienced by incumbent receivers as a result of licensee activity
on shared spectrum may decrease proportionally to the distance from
the licensee shared spectrum uplink user terminals, the
interference to the incumbent cell may be sufficient to disrupt
incumbent activity (which licensee base station 310 may detect via
user measurement, as will be later detailed). Accordingly, the
interference to incumbent receivers caused by the random selection
of licensee shared spectrum uplink user terminals may fail to meet
the protection levels defined for protection zone shared spectrum
operation, and accordingly licensee base station 310 may need to
enact power control measures in order to reduce the interference
level to appropriate levels. Licensee base station 310 may thus
choose to reduce the number of licensee shared spectrum uplink user
terminals (e.g. by terminating shared spectrum uplink activity for
one or more licensee shared spectrum uplink user terminals), reduce
the permitted shared spectrum uplink transmit power for some or all
licensee shared spectrum uplink user terminals, or other similar
power control measures, in order to reduce the interference seen by
the incumbent users.
[0076] However, arbitrary or uniform selection of shared spectrum
uplink user terminals to prohibit or limit from using shared
spectrum for uplink may not be particularly effective. As shown in
FIG. 3, arbitrary or uniform power control measures may
inadvertently disable or reduce shared spectrum uplink operation
for licensee user terminals that are located far from the incumbent
cell, which may only have a minimal effect on the interference
experienced by the incumbent. Additionally, licensee base station
310 may inadvertently allow licensee user terminals located close
to the incumbent cell to continue using shared spectrum for uplink
transmissions, which may continue to contribute excessive
interference to the incumbent.
[0077] As opposed to arbitrary or uniform restriction of shared
spectrum uplink activity, licensee base station 310 may instead
intuitively select which licensee user terminals to assign for
shared spectrum uplink operation based on the estimated location of
licensee user terminals relative to the incumbent cell. Licensee
base station 310 may thus choose to perform uplink power control
measures based on which licensee user terminals are closest and
furthest from the incumbent cell, and thus may select which
licensee user terminals to allow to utilize shared spectrum uplink
and select appropriate shared spectrum uplink transmit powers for
such licensee user terminals accordingly.
[0078] Specifically, licensee base station 310 may, i.e. at uplink
control circuit 318, analyze radio measurements provided by the
licensee user terminals in order to identify which licensee user
terminals are located closest to and which licensee user terminals
are located furthest from the incumbent cell. Uplink control
circuit 318 may then select licensee user terminals that are
located closest to the incumbent cell to utilize as measurement
terminals, which may then perform radio measurements to report to
licensee base station 310 that indicate the level of interference
to the incumbent caused by uplink licensee radio activity. Uplink
control circuit 318 may then determine if uplink power control
measures are warranted based on the interference estimations, and,
if so, may subsequently apply the previously obtained information
about proximity to the incumbent cell in order to decide
appropriate power control measures. For example, uplink control
circuit 318 may restrict or reduce uplink activity on shared
spectrum for licensee user terminals located closest to the
incumbent cell and permit or only marginally reduce uplink activity
for licensee user terminals located furthest from the incumbent
cell.
[0079] FIG. 5 shows an exemplary result of such an uplink
interference management procedure performed by licensee base
station 310 at uplink control circuit 318. As shown in FIG. 5,
uplink Control circuit 318 may authorize licensee user terminals
located furthest from the incumbent cell to utilize shared spectrum
for uplink while denying shared spectrum uplink usage to licensee
user terminals located closest to the incumbent cell. The
interference experienced by the incumbent may thus be reduced as
depicted by the exemplary interference shading for incumbent users.
As will be later detailed, uplink control circuit 318 may
additionally select licensee user terminals that are located
closest to the incumbent cell as measurement terminals, which may
report uplink interference estimations to uplink control circuit
318 for use in applying uplink shared spectrum power control.
[0080] Uplink control circuit 318 may thus need to characterize the
distance between each licensee user terminal and the incumbent
cell. Accordingly, uplink control circuit 318 may employ a
"ranking" scheme based on signal power measurements of incumbent
signals obtained by the licensee user terminals. For example,
uplink control circuit 318 may obtain incumbent signal power
estimates from each licensee user terminal and rank the licensee
user terminals based thereon to obtain an incumbent cell proximity
ranking, where uplink control circuit 318 may characterize licensee
user terminals that report the strongest incumbent signal power
estimates as being located closest to the incumbent cell and
conversely characterizes licensee user terminals that report the
weakest incumbent signal power estimates as being located furthest
from the incumbent cell. Uplink control circuit 318 may then
utilize the incumbent signal power ranking to select measurement
terminals (located closest to the incumbent cell) and perform
uplink shared spectrum power control.
[0081] Uplink control circuit 318 may have several options for
obtaining the incumbent power measurements in order to characterize
licensee user terminal distance from the incumbent cell. In a first
approach, uplink control circuit 318 may rely on incumbent silence
periods, which may need to be specifically configured as part of
incumbent operation. In such incumbent silence periods, incumbent
transmitters may be configured to cease transmission, thus
resulting in a "silence" time period in which no incumbent
transmitters are active. Uplink control circuit 318 may then
instruct licensee user terminals via control signaling to perform
radio measurements during these incumbent silence periods in
addition to performing further radio measurements during standard
incumbent operation periods, i.e. when incumbent base stations and
incumbent users are active. The licensee user terminals may then
report the obtained silence and non-silence radio measurements back
to uplink control circuit 318.
[0082] Under the assumption of constant noise and incumbent signal
power, uplink control circuit 318 may identify which licensee user
terminals are closest to the incumbent cell by evaluating the
difference in non-silence and silence period signal power
measurements supplied by each licensee user terminal, where uplink
control circuit 318 may identify licensee user terminals with the
largest difference between non-silence and silence period
measurements as being closest to the incumbent cell (due to high
incumbent signal power measurements) and licensee user terminals
with the smallest difference between non-silence and silence period
measurements as being furthest from the incumbent cell. Uplink
control circuit 318 may then rank the licensee user terminals based
on the estimated distance (or equivalently based on non-silence to
silence difference). However, incumbent silence periods may need to
be incorporated into incumbent operational behavior (which may or
may not be feasible), and additionally may limit incumbent
operating times due to the system downtime required for such
silence periods.
[0083] Instead, in a second approach, the licensee user terminals
may obtain incumbent signal power estimates by using downlink
reference signal measurements to isolate the incumbent signal power
from received downlink signals. By isolating the incumbent signal
power from received downlink signals, the licensee user terminals
may obtain an accurate estimation of incumbent signal power
(without the need for incumbent silence periods). The licensee user
terminals may then provide the incumbent signal power estimates to
uplink control circuit 318, which may evaluate the incumbent signal
power estimates to perform uplink power control procedures (if
necessary)
[0084] Specifically, a licensee user terminal such as licensee user
terminal 410 may estimate the received signal power of a downlink
reference signal and subtract the estimated downlink reference
signal power from a downlink signal power measurement. By
exploiting properties of certain downlink reference signals and
assuming constant noise, licensee user terminal 410 may isolate the
incumbent signal power from the downlink signal power measurement,
thus obtaining a measurement for uplink control circuit 318 to
apply in order to identify incumbent-proximate and
incumbent-distant users.
[0085] FIG. 6 shows method 600 for performing uplink power control.
Licensee base station 310 may execute method 600, such as at uplink
control circuit 318 via radio processing circuit 314 and antenna
system 312 for receiving and transmitting operations. Uplink
control circuit 318 may execute method 600 as a component of the
licensee network (such as at an LSA entity contained within the
licensee network) or as a component outside of the licensee network
(such as an SAS entity located outside of the licensee network).
Alternatively, uplink control circuit 318 may be distributed
partially inside and partially outside of the licensee network,
such as an SAS component split into two parts as an
intra-network-domain SAS component and an extra-network-domain SAS,
and accordingly may execute method 600 partially in the
intra-network domain SAS and in the extra-network-domain SAS.
[0086] Uplink control circuit 318 may first request incumbent
signal power estimations from licensee user terminals in 610,
during which uplink control circuit 318 may transmit (via baseband
processing circuit 316, radio processing circuit 314, and antenna
system 312) control signaling to the licensee user terminals that
requests incumbent signal power estimates. Uplink control circuit
318 may either request incumbent signal power estimations for a
single-instance (i.e. one-time), periodically, or autonomously
(i.e. allowing the licensee user terminals to provide incumbent
signal power estimates autonomously). Uplink control circuit 318
may then receive (via baseband processing circuit 316, radio
processing circuit 314, and antenna system 312) incumbent signal
power estimates from the licensee user terminals in 604 (where the
incumbent signal power estimation procedure will be later detailed)
as measurement reports and proceed to evaluate the incumbent signal
power estimates in 606. As previously indicated, uplink control
circuit 318 may characterize the incumbent cell distance for each
licensee user terminal based on the reported incumbent signal power
estimates in 606, such as by ranking the licensee user terminals
based on reported incumbent signal power estimates. Uplink control
circuit 318 may rank licensee user terminals that report the
strongest incumbent signal power estimates as being closest to the
incumbent cell and licensee user terminals that report the weakest
incumbent signal power estimates as being furthest from the
incumbent cell. Uplink control circuit 318 may utilize any of a
number of alternative ranking criteria, such as according to Bit
Error Rate (BER)/Packet Error Rate (PER), Signal
(plus-Interference)-to-Noise Ratio (SNR), call drop rates, etc.
[0087] Alternatively to utilizing incumbent signal power estimates
to characterize the incumbent cell distance for licensee user
terminals, uplink control circuit 318 may utilize other mobile
terminal location mechanisms such as Global Positioning Systems
(GPS), Observed Time Difference of Arrival (OTDOA) positioning,
etc., in order to identify the location of each licensee user
terminal. However, such may have limited effectiveness as uplink
control circuit 318 may not have exact knowledge of the location of
the incumbent cell, and accordingly may not be able to rely on
absolute user terminal positioning information to determine the
proximity of each licensee user terminal to the incumbent cell.
Regardless it is appreciated that alternative licensee user
positioning mechanisms may be similarly employed. Uplink control
circuit 318 may utilize the incumbent cell distance to both select
suitable measurement terminals for reporting uplink interference
estimates and, if needed, for selecting licensee user terminals to
restrict or limit during shared spectrum uplink power control.
[0088] Accordingly, uplink control circuit 318 may in 608 select
one or more measurement terminals from the licensee user terminals
based on the incumbent cell distance for the licensee user
terminals obtained in 606. For example, uplink control circuit 318
may e.g. select a predefined quantity of the licensee user
terminals that report the strongest incumbent signal power
estimates as the measurement terminals or may e.g. select all
licensee user terminals that report incumbent signal power
estimates that satisfy predefined criteria (e.g. a threshold) as
the measurement terminals. Uplink control circuit 318 may then
assign the selected licensee user terminals as measurement
terminals and request uplink interference estimations from the
measurement terminals via control signaling in 608. After
requesting uplink interference estimates, uplink control circuit
318 may receive the uplink interference estimates from the
measurement terminals as measurement reports in 610. Uplink control
circuit 318 may then analyze the reported uplink interference
measurements to determine whether shared spectrum uplink power
control is needed in 612.
[0089] As previously indicated, uplink control circuit 318 may need
to manage interference to the incumbent caused by uplink shared
spectrum activity to keep such uplink interference within
acceptable levels, such as by managing uplink radio activity on
shared spectrum to ensure that uplink interference remains below a
predetermined threshold (e.g. a protection zone uplink interference
threshold). Accordingly, uplink control circuit 318 may evaluate
the reported uplink interference estimates in 612 to determine if
the current levels of uplink interference indicated by the reported
uplink interference estimates are within acceptable levels and, if
not, engage in power control for uplink transmissions on the shared
spectrum.
[0090] As uplink control circuit 318 may select the licensee user
terminals closest to the incumbent cell (on the basis of received
incumbent signal power) as the measurement terminals (as shown in
FIG. 5), the measurement terminals may provide accurate
interference level measurements. Uplink control circuit 318 may
aggregate the reported uplink interference estimations, such as by
computing an average, selecting a median, etc., to determine an
accurate uplink interference measurement from the reported uplink
interference measurements. Uplink control circuit 318 may then
compare the aggregated uplink interference measurement to
predefined criteria, such as predefined uplink interference
threshold, to determine whether uplink power control measures are
necessary.
[0091] As shown in FIG. 5, the measurement terminals may not
actually be located in the incumbent cell (although such is
nevertheless possible), and accordingly incumbent receivers may see
greater interference than indicated by the "raw" (i.e. unadjusted)
uplink interference estimations reported by the measurement
terminals. As the incumbent cell is located further from the
interfering licensee user terminals than the measurement terminals,
the measurement terminals may consistently report higher uplink
interference estimates than actually experienced by incumbent
receivers. Accordingly, uplink control circuit 318 may select
appropriate interference level criteria to utilize for comparison
with the "raw" uplink interference estimations reported by the
measurement terminals, such as by using an uplink interference
threshold that is higher than the actual uplink interference
threshold desired for the incumbent cell. Furthermore, as some
measurement terminals are located closer to the incumbent cell than
others, uplink control circuit 318 may perform a weighted
aggregation, such as by weighting each reported uplink interference
estimation based on the estimated incumbent signal power reported
by each measurement terminal, i.e. with the most
incumbent-proximate measurement terminals (highest reported
estimated incumbent signal power measurement) having greater weight
than the least incumbent-proximate measurement terminals.
[0092] Alternatively to utilizing uplink interference estimations
based on uplink interference measurements obtained by the
measurement terminals, uplink control circuit 318 may instead be
configured to estimate the uplink interference, such as based on
licensee user terminal locations (as indicated by reported
incumbent signal power estimates, GPS, OTDOA, or other mobile
terminal positioning mechanisms). For example, uplink control
circuit 318 may be able to perform an interference estimation
simulation that considers the uplink transmit power allocated to
each licensee user terminal and the location of each licensee user
terminal (either absolute location or relative distance to the
incumbent). Accordingly, uplink control circuit 318 may be able to
calculate an estimated interference contribution by each licensee
user terminal based on the uplink transmit power and location, and
calculate the cumulative interference to the uplink by aggregating
the estimated interference contributions by each licensee user
terminal. Such may allow for power saving at licensee user
terminals (due to the absence of uplink interference calculations)
but may be prone to greater estimation errors depending on the
accuracy of the estimation calculation employed by uplink control
circuit 318.
[0093] The interference measurements obtained at uplink control
circuit 318 may relate to a neighboring signal power that affects
transmission of a concerned signal of uplink control circuit 318.
The neighboring signal power associated with the interference
measurements may occur sporadically, continuously, continuously
with some interruptions, etc. The level of interference may also
vary over time, e.g. the interference level may occasionally
increase and subsequently decrease and/or vice versa. The
interference can also relate to in-band interference or blocking
effects or out-of-band/spurious emission or any unwanted emissions
effects of a certain system affecting a neighboring system (e.g.
due to insufficient filtering of unwanted emissions in the
concerned network equipment). Uplink control circuit 318 may thus
apply method 600 to reduce such interference effects. Furthermore,
the interference effects may only concern a subset of users in a
given network/cell/etc. targeted by uplink control circuit 318. For
example, directive transmissions (such as e.g. MIMO
beamforming-based) may occur in the context of cmWave and mmWave
transmissions (cmWave: 3-30 GHz; mmWave: 30-300 GHz). Uplink
control circuit 318 may then identify the interference area (e.g.
based on 2D and/or 3D transmission angle to the concerned equipment
applying beamforming) and apply method 600 in the context of
interference reduction/avoidance to only to the concerned devices.
Typically, devices having beamforming directions pointing away from
the concerned neighboring network(s) may be able to use any
configuration as interference will be minimal.
[0094] Uplink control circuit 318 may thus obtain an estimated
uplink interference, which may be an aggregated uplink interference
estimate derived from radio measurements and/or interference
simulations. Uplink control circuit 318 may thus determine if the
estimated uplink interference experienced by the incumbent falls
within acceptable levels or not in 612. If the estimated uplink
interference does not fall within acceptable levels, uplink control
circuit 318 may initiate power control for shared spectrum uplink
in 614.
[0095] Uplink control circuit 318 may utilize instantaneous uplink
interference measurements in 612 and 614 (and subsequently
re-evaluate updated interference measurements if the interference
measurements change), average interference measurements calculated
as an average over a predefined period of time, maximum (or e.g.
average or minimum) interference measurements obtained over a
predefined period of time, or any other statistical and/or
deterministic interference measurement.
[0096] Uplink control circuit 318 may utilize the incumbent cell
distance characterization determined in 606 in order to perform
uplink power control. As shown in FIG. 5, certain licensee user
terminals may be located close to the incumbent cell (which may
have been selected as measurement terminals in 608) while other
licensee user terminals may be located distant from the incumbent
cell. Licensee user terminals proximate to the incumbent cell may
contribute far more interference to incumbent receivers than
licensee user terminals distant from the incumbent cell, and uplink
control circuit 318 may thus efficiently reduce uplink interference
by either prohibiting the proximate licensee user terminals from
using shared spectrum for uplink or by assigning the proximate
licensee user terminals relatively low uplink transmit powers.
[0097] Accordingly, uplink control circuit 318 may consider
incumbent cell distance during shared spectrum uplink power control
procedures. Specifically, uplink control circuit 318 may weight
uplink power control procedures towards restricting or limiting
licensee user terminals that are located closest to the incumbent
cell, such as introduced regarding FIG. 5. Uplink control circuit
318 may allow only certain licensee user terminals to utilize
shared spectrum for uplink and/or may assign specific shared
spectrum uplink transmit powers for certain licensee user
terminals.
[0098] For example, if uplink control circuit 318 determines in 612
that shared spectrum uplink power control is needed, uplink control
circuit 318 may rank the licensee user terminals in order according
to reported incumbent signal power estimate (received in 604) and
subsequently select a certain number of licensee user terminals to
authorize for shared spectrum uplink while prohibiting the
remaining licensee user terminals from utilizing shared spectrum
for uplink. It is noted that the remaining licensee user terminals
may still be permitted to utilize the shared spectrum for downlink,
and additionally may be able to utilize standard licensed spectrum
for both uplink and/or downlink.
[0099] Alternative to either allowing or not allowing licensee user
terminals to utilize shared spectrum for uplink, uplink control
circuit 318 may assign varying shared spectrum uplink transmit
powers to each licensee user terminal based on the incumbent signal
power estimate ranking. For example, uplink control circuit 318 may
assign high shared spectrum uplink transmit powers to licensee user
terminals that are located furthest from the incumbent cell, and
conversely assign low (or none) shared spectrum uplink transmit
powers to licensee user terminals located closest to the incumbent
cell. The licensee user terminals reporting the highest incumbent
signal power measurements may thus be allocated the lowest SUL
transmit powers or may be completely prohibited from any SUL
transmissions.
[0100] Alternatively, uplink control circuit 318 may compare the
incumbent signal power estimates reported by each licensee user
terminal to a predetermined threshold. Uplink control circuit 318
may then permit each licensee user terminal that reports an
incumbent signal power measurement below the predetermined
threshold to utilize shared spectrum for uplink while prohibiting
the remaining licensee user terminals that report incumbent signal
power measurements above the predetermined threshold from using
shared spectrum for uplink. However, such a threshold-based scheme
may have increased sensitivity to noise conditions, as each
licensee user terminal may report high incumbent signal power
measurements in the event that the licensee cell is subject to high
noise conditions (as will be detailed below regarding incumbent
signal power estimates by licensee user terminals). uplink control
circuit 318 may as a result unnecessarily prohibit licensee user
terminals from shared spectrum uplink usage that are not
substantially close to the incumbent cell due to erroneously high
reported incumbent signal power estimates.
[0101] Uplink control circuit 318 may additionally consider
beamforming capabilities of the licensee user terminals when
executing shared spectrum uplink power control in 614. For example,
one or more licensee user terminals may include sufficient antenna
systems that allow the licensee user terminals to transmit
directive beams, i.e. uplink beamforming. Accordingly, such
licensee user terminals may be able to direct uplink transmissions
to licensee base station 310, which subsequently may reduce the
amount of interference caused to the incumbent. Accordingly, uplink
control circuit 318 may allocate higher uplink transmit powers for
such licensee user terminals than licensee user terminals that are
not capable of beamforming.
[0102] Uplink control circuit 318 may additionally consider whether
the shared spectrum uplink transmit power of licensee user
terminals is sufficient for licensee base station 310 to receive
uplink transmissions. For example, if a licensee user terminal
utilizes a shared spectrum uplink transmit power that is too weak,
licensee base station 310 may not be able to successfully receive
uplink transmissions from the licensee user terminal. Uplink
control circuit 318 may thus face scenarios where uplink control
circuit 318 needs to reduce the shared spectrum uplink transmit
power of a given licensee user terminal due to excessive
interference, but doing so would result in insufficient shared
spectrum uplink transmit power for licensee base station 310 to
receive uplink transmission from the given licensee user terminal.
Uplink control circuit 318 may instead allocate the given licensee
user terminal to uplink transmissions on dedicated licensed
spectrum instead of shared spectrum (assuming dedicated licensed
spectrum is available) or may attempt to reduce the allocated
shared spectrum uplink transmit power of one or more additional
licensee user terminals in order to "compensate" for the excessive
interference caused by the given licensee user terminal.
[0103] It is also noted that only some of the licensee user
terminals may need or have requested uplink transmission resources,
and accordingly not all of the licensee user terminals may need to
utilize uplink in any capacity. Uplink control circuit 318 may thus
not consider such licensee user terminals for uplink transmit power
allocation.
[0104] After determining appropriate shared spectrum uplink power
control procedures in 614, uplink control circuit 318 may transmit
control signaling to each licensee user terminal that specifies a
shared spectrum uplink resource allocation, i.e. whether a given
licensee user terminal is permitted to use shared spectrum for
uplink and, if so, an allotted shared spectrum uplink transmit
power (which may be a maximum allowed shared spectrum uplink
transmit power).
[0105] Uplink control circuit 318 may thus be able to obtain a
shared spectrum uplink allocation similar to as shown in FIG. 5,
where only certain licensee user terminals located furthest from
the incumbent cell are permitted to use shared spectrum for uplink.
Depending on the criteria utilized for shared spectrum uplink
allocation, uplink control circuit 318 may be able to adjust the
distribution of shared spectrum uplink-enabled licensee user
terminals relative to the incumbent cell. For example, uplink
control circuit 318 may only allow the furthest licensee user
terminals to utilize shared spectrum for uplink if a "stricter"
shared spectrum uplink allocation criteria is employed (i.e. only
allowing a very limited number of shared spectrum uplink-enabled
licensee user terminals and/or utilizing a very low reported
incumbent signal power measurement threshold), while in contrast
uplink control circuit 318 may allow the furthest licensee user
terminals in addition to closer licensee user terminals to utilize
shared spectrum uplink if a "more relaxed" shared spectrum uplink
allocation criteria is employed (i.e. allowing a greater number of
shared spectrum uplink-enabled licensee user terminals and/or
utilizing a higher reported incumbent signal power measurement
threshold).
[0106] Uplink control circuit 318 may apply a dynamic approach to
shared spectrum uplink power control, and accordingly may adjust
the shared spectrum uplink allocation (i.e. which licensee user
terminals are allowed to transmit uplink on shared spectrum and, if
so, what shared spectrum uplink transmit power such mobile
terminals are permitted to use) and/or the measurement terminals
over time.
[0107] As depicted in FIG. 6, uplink control circuit 318 may return
to 610 if uplink control circuit 318 determines that shared
spectrum uplink power control is not needed in 612. Accordingly,
uplink control circuit 318 may obtain updated uplink interference
estimations from the measurement terminals in 610, and again
proceed to 612 in order to determine if shared spectrum uplink
power control is needed based on the updated uplink interference
measurements.
[0108] Similarly, as opposed to terminating method 600 following
614, uplink control circuit 318 may instead return to 610 (not
explicitly mapped in FIG. 6) to re-evaluate the shared spectrum
uplink interference based on updated shared spectrum uplink
estimations in 612. Uplink control circuit 318 may perform such a
repetition periodically in order to continuously re-evaluate the
current shared spectrum uplink interference over time in order to
ensure that shared spectrum uplink interference conditions remain
within acceptable levels.
[0109] Additionally or alternatively, uplink control circuit 318
may return to 602 following completion of 614 (or alternatively
following a negative result in 612; neither explicitly mapped in
FIG. 6), and accordingly may re-evaluate updated incumbent signal
power estimations reported by licensee user terminals in 602-604.
Uplink control circuit 318 may then utilize the updated incumbent
signal power estimations in order to obtain a new incumbent cell
distance for the licensee user terminals based on the updated
incumbent signal power estimations. As the licensee user terminals
may be mobile, such may ensure that uplink control circuit 318
maintains an accurate characterization of the distance from the
incumbent cell of each licensee user terminal.
[0110] Uplink control circuit 318 may then utilize the update
incumbent cell distances for each licensee user terminal (as
indicated by reported incumbent signal power estimates) in order to
re-select measurement terminals and/or in order to perform shared
spectrum uplink power control (if needed) in 614.
[0111] Such a dynamic approach may be advantageous as uplink
control circuit 318 may be able to obtain "feedback" from the
shared spectrum uplink power control performed in 614. For example,
uplink control circuit 318 may select certain licensee user
terminals to allow to utilize shared spectrum uplink in 614 in
order to reduce shared spectrum uplink interference to the
incumbent, and may subsequently obtain updated shared spectrum
uplink interference estimates from the measurement terminals in 610
(after returning to 610 following 614). Accordingly, uplink control
circuit 318 may be able to determine whether the initial shared
spectrum uplink power control in 614 was effective in reducing
shared spectrum uplink interference to within acceptable levels
and, if not, perform further shared spectrum uplink power control
(e.g. by allowing fewer licensee user terminals to utilize shared
spectrum uplink) in 614. Uplink control circuit 318 may repeat such
in a continuous process, and may use shared spectrum uplink
transmit power allocations in an analogous manner.
[0112] Uplink control circuit 318 may additionally be configured to
"increase" shared spectrum uplink allocations in the event that
shared spectrum interference estimates indicate in 612 that the
current shared spectrum uplink interference is appreciably within
acceptable levels. For example, as previously detailed uplink
control circuit 318 may compare an aggregated shared spectrum
uplink interference estimates (obtained via shared spectrum uplink
interference estimates reported by the measurement terminals in
610) to a predetermined threshold in 614 and initiate shared
spectrum uplink power control if the aggregated shared spectrum
uplink interference estimate exceeds the predetermined threshold.
However, if the aggregated shared spectrum uplink interference
estimate falls below the predetermined threshold, uplink control
circuit 318 may be able to "increase" shared spectrum uplink
allocation for the licensee user terminals, such as by permitting
more licensee user terminals to utilize shared spectrum for uplink
and/or increasing the allowed shared spectrum uplink transmit
powers for licensee user terminals. Similarly to as detailed above,
uplink control circuit 318 may dynamically evaluate the result of
such "increases" in shared spectrum uplink allocation to determine
if the shared spectrum interference level remains within acceptable
levels and perform further increases in shared spectrum uplink
allocation or initiate shared spectrum uplink power control
measures accordingly. Uplink control circuit 318 may utilize such
allowable increases in shared spectrum uplink transmit power in
order to ensure that licensee user terminals have sufficient uplink
transmit power to successfully transmit uplink signals to licensee
base station 310.
[0113] Uplink control circuit 318 may additionally be configured to
perform more aggressive shared spectrum uplink power control in 614
(and conversely more aggressive increases in shared spectrum uplink
allocation) dependent on the aggregated shared spectrum uplink
interference estimate. For example, if the aggregated shared
spectrum uplink interference estimate exceeds a predetermined
interference threshold by a substantial amount, uplink control
circuit 318 may aggressively reduce the number of licensee user
terminals permitted to utilize shared spectrum for uplink and/or
aggressively reduce the allowed shared spectrum uplink transmit
powers. Conversely, uplink control circuit 318 may only slightly
reduce the number of licensee user terminals permitted to utilize
shared spectrum for uplink and/or slightly reduce the allowed
shared spectrum uplink transmit power if the aggregated shared
spectrum uplink interference estimate exceeds a predetermined
interference threshold by only a small amount.
[0114] FIG. 7 shows method 700, which may be performed by each
licensee user terminal at a baseband processing circuit.
Accordingly, a licensee user terminal such as licensee user
terminal 410 may execute method 600 at baseband processing circuit
416, which may interact with radio processing circuit 414 and
antenna system 412 in order to receive and transmit wireless
signals.
[0115] Baseband processing circuit 416 may receive an incumbent
signal power estimation request as control signaling from licensee
base station 310 at 702, which may request a single-instance
incumbent signal power estimate, periodic incumbent signal power
estimates, or autonomous incumbent signal power estimates.
[0116] Baseband processing circuit 416 may then perform the
incumbent signal power estimation and report the incumbent signal
power estimate to licensee base station 310 as control signaling
(e.g. a measurement report) in 704.
[0117] Baseband processing circuit 416 may utilize downlink
reference signals in order to isolate the incumbent signal power
from received downlink signals, thus obtaining an incumbent signal
power estimate to report back to licensee base station 310. The
incumbent signal power estimation and reporting procedure of 704
may be summarized as follows: [0118] 704a. Receive time-domain
downlink signal [0119] 704b. Obtain frequency-domain downlink
signal [0120] 704c. Perform downlink signal power measurement
[0121] 704d. Calculate cross-correlation of frequency domain
downlink signal with known frequency-domain downlink reference
signal to obtain downlink reference signal channel response [0122]
704e. Calculate estimated downlink reference signal power from
downlink reference signal channel response [0123] 704f. Subtract
estimated downlink reference signal power from downlink signal
power measurement to obtain estimated incumbent signal power [0124]
704g. Report estimated incumbent signal power to licensee base
station 310
[0125] In contrast to requiring incumbent silence periods to obtain
incumbent signal power estimates, licensee user terminal 410 may be
able to exploit properties of downlink reference signals in order
to obtain incumbent signal power estimates without adjusting
incumbent operation. Specifically, various mobile communication
standards may utilize downlink reference signals to periodically
evaluate downlink channel quality as well as to maintain timing and
frequency synchronization between a base station and user. In
particular for an LTE context as specified by 3GPP, base stations
may periodically transmit downlink reference signals including
Primary Synchronization Signals (PSSs), Secondary Synchronization
Signals (SSSS), and Cell-specific Reference Signals (CRSs), which
base stations may transmit according to a certain predefined
configuration (i.e. pattern) in time and frequency. Similar
downlink reference signals may be provided depending on mobile
communication technologies and may be utilized in an analogous
manner, in particular downlink reference signals that offer high
levels of independence (i.e. low correlation) from other wireless
signals.
[0126] Baseband processing circuit 410 may thus receive a
time-domain downlink signal y.sub.d (t) at 704a during a specific
reference signal reception period (i.e. symbol interval(s)
containing a PSS, SSS, CRS symbol, etc.). Although any such
downlink reference signal may be utilized, PSS may be of particular
interest as a transmitting base station may only transmit PSS
symbols during a PSS symbol interval, i.e. may not transmit any
other downlink symbols other than PSS symbols (distributed over 62
central subcarrier of the LTE system bandwidth for a single symbol
interval) during a PSS occasion. However, it is noted that any
downlink reference signal may be analogously employed, in
particular downlink reference signals that allow for separation of
the downlink reference signal from other downlink signals, such as
by correlation properties as will be detailed below.
[0127] Accordingly, baseband processing circuit 410 may receive
downlink signal y.sub.d (t) during a PSS occasion of licensee base
station 310 given as
y.sub.d(t)=h.sub.rs(t)x.sub.rs(t)+h.sub.inc(t)x.sub.inc(t)+n(t),
(1)
where h.sub.rs(t) is the impulse response of the reference signal
channel (i.e. from licensee base station 310 to licensee user
terminal 410), x.sub.rs(t) is the time-domain reference signal
transmitted by licensee base station 310, h.sub.inc(t) is the
impulse response of the channel between the incumbent cell (may be
cumulative across all incumbent users and base stations in the
context of Equation (1)), x.sub.inc(t) is the time-domain signal
transmitted by the incumbent cell (may be cumulative across all
incumbent users and base stations in the context of Equation (1),
and n(t) is the time-domain noise signal. Baseband processing
circuit 416 may either receive the downlink signal during a
downlink subframe if the shared spectrum is utilized for a TDD
system or receive the downlink signal on a downlink band if the
shared spectrum is utilized for an FDD system. As the incumbent
signal x.sub.inc(t) originates from the incumbent, baseband
processing circuit 410 may not be able to decode or demodulate the
incumbent signal x.sub.inc(t).
[0128] Baseband processing circuit 416 may then transform the
received time-domain downlink signal of Equation (1) into the
frequency domain in 704b (e.g. by utilizing a frequency transform
operation such as a Fast Fourier Transform (FFT)) to yield
Y.sub.d(f)=H.sub.rs(f)*X.sub.rs(f)+H.sub.inc(f)*X.sub.inc(f)+N(f),
(2)
where Y.sub.d), H.sub.rs(f), X.sub.rs(f), H.sub.inc(f),
X.sub.inc(f), and N(f) give the respective frequency representation
of y.sub.d (t), h.sub.rs(t), x.sub.rs(t), h.sub.inc (t),
x.sub.inc(t), and n(t) and * denotes the convolution operation.
[0129] Baseband processing circuit 416 may additionally perform a
downlink signal power measurement (such as e.g. a Received Signal
Strength Indicator (RSSI) or similar signal power measurement) on
y.sub.d (t) in order to obtain the overall downlink signal power
P.sub.d in 704c given as
P.sub.d=P.sub.rs+P.sub.inc+P.sub.n, (3)
where P.sub.d is the total received downlink signal power, P.sub.rs
is the received downlink reference signal power, P.sub.inc is the
received incumbent signal power, and P.sub.n is the received noise
power.
[0130] As licensee base station 310 may not transmit any other
downlink symbols during a PSS occasion, downlink signal
measurements by baseband processing circuit 416 on shared spectrum
may only be composed of the reference signal, incumbent signal, and
noise. While the following description may substantially focus on
the application of PSS as the downlink reference signal, alternate
downlink reference signals such as the aforementioned SSS and CRS
in addition to other reference signals unique to other mobile
communication technologies may analogously employed. However,
certain downlink reference signals such as CRS may not offer the
advantage of PSS of isolated downlink reference signals, i.e. base
stations may transmit other downlink symbols during the same symbol
interval as CRS symbols. Accordingly, Equations (1) to (3) may
include additional contributions from other downlink symbols, and
accordingly may not provide as accurate downlink measurements or
may require further processing to isolate the received downlink
signal.
[0131] As specified by 3GPP, PSSs may be predefined sequences known
to both the base station and user, where each PSS is a Zadoff-Chu
sequence composed of 64 symbols generated with a specific sequence
root (with three possible roots in an LTE context, thus yielding
three possible PSS sequences). Such Zadoff-Chu sequences are
characterized as constant amplitude zero autocorrelation (CAZAC)
sequences, and accordingly exhibit special correlation and
autocorrelation properties. As a result, PSSs are substantially
independent from other signals, and accordingly will exhibit
substantially no correlation with signals other than matching PSSs,
where a PSS root sequence will produce a delta dirac function
.delta. when correlated with a zero-shifted version of itself and
substantially zero correlation with another signal. It is
appreciated that other downlink reference signals, including both
CRS (based on Gold sequences) and SSS (based on pseudorandom noise
sequences), may similarly exhibit a level of independence from
other signals and may analogously be applied for the reference
signal isolation.
[0132] Due to the aforementioned correlation characteristics of
PSSs, the following correlations hold
X.sub.rs(f) X.sub.rs(f)=.delta.(f),X.sub.rs(f) X.sub.inc(f)=0,
x.sub.rs(f) N(f)=0,X.sub.ul(f) N(f)=0, (4)
where .delta.(f) denotes the delta dirac function and denotes the
cross-correlation operation.
[0133] Accordingly, baseband processing circuit 416 may isolate the
downlink reference signal channel frequency response H.sub.rs(f) by
calculating the cross-correlation between the frequency-domain
received downlink signal Y.sub.d(f) and the frequency transform of
the downlink reference signal X.sub.rs(f) in 704d as follows
Y.sub.d(f) X.sub.rs(f)=H.sub.rs(f). (5)
[0134] As previously indicated, downlink reference signals such as
PSS may be predefined and thus known at both base stations and user
terminals. Accordingly, each licensee user terminal may have prior
knowledge of the downlink reference signal in both x.sub.rs(t) and
the corresponding frequency representation X.sub.rs(f) (e.g. as
each licensee user terminal will have previously determined the
group identity of licensee base station 310 during synchronization
and subsequent tracking using PSS).
[0135] Accordingly, baseband processing circuit 416 may isolate
H.sub.rs(f) from the received downlink signal Y.sub.d(f) via
cross-correlation as given in Equation (5). Baseband processing
circuit 416 may then calculate the estimated downlink reference
signal power {circumflex over (P)}.sub.rs (estimation of P.sub.rs
from Equation (3)) in 704e as
P ^ rs = 1 N [ H rs ( f ) * X rs ( f ) ] = 1 N [ X rs ( f ) * [ Y d
( f ) .star-solid. X rs ( f ) ] ] . ( 6 ) ##EQU00001##
[0136] Upon calculating {circumflex over (P)}.sub.rs from the
received downlink signal Y.sub.d(f), baseband processing circuit
416 may subsequently subtract {circumflex over (P)}.sub.rs from the
received downlink signal power P.sub.d in 704f to yield
P d - P rs = P rs - P ^ rs + P inc + P n , .apprxeq. P inc + P n ,
( 7 ) ##EQU00002##
where P.sub.rs-{circumflex over (P)}.sub.rs.apprxeq.0 assuming an
accurate estimate in the calculation of {circumflex over
(P)}.sub.rs in Equation (6).
[0137] Baseband processing circuit 416 may then report the
estimated incumbent signal power obtained from Equation (7) to
licensee base station 310 as control signaling (e.g. as a
measurement report). Such may be repeated at each licensee user
terminal, and accordingly each licensee user terminal may thus
obtain a signal power measurement containing the incumbent power
and noise power. As previously indicated, noise may be
statistically assumed constant over space and time for purposes of
incumbent power estimation relative to licensee base station 310,
and accordingly the signal power measurement obtained by each
licensee user terminal may be assumed to contain a substantially
equivalent contribution from noise. As the noise power may be
assumed constant signal power measurements at all licensee user
terminals, each licensee user terminal may then report the
estimated incumbent signal power measurement for P.sub.d-P.sub.rs
to licensee base station 310 (e.g. as a measurement report via
control signaling). Alternatively, each licensee user terminal may
process report the estimated incumbent signal power measurement for
P.sub.d-P.sub.rs in order to remove a noise estimate {circumflex
over (P)}.sub.n therefrom.
[0138] Accordingly, each licensee user terminal may obtain an
incumbent signal power estimate by processing downlink signals
according to known properties of downlink reference signals.
Licensee base station 310 may then receive and evaluate these
incumbent signal power estimations in 604 and 606 of method 600 to
characterize the incumbent cell distance for each licensee user
terminal, where licensee base station 310 may characterize licensee
user terminals that report the strongest incumbent signal power
estimates as being located the closest to the incumbent cell and
licensee user terminals that report the weakest incumbent signal
power estimates as being located the furthest from the incumbent
cell. As previously detailed, licensee base station 310 may select
measurement terminals and/or perform shared spectrum uplink power
control based on the reported incumbent signal power estimates.
[0139] Following incumbent signal power estimation reporting in
704, baseband processing circuit 416 may determine in 706 whether
licensee user terminal 410 has been assigned as a measurement
terminal, which may include receiving control signaling specifying
whether licensee user terminal 410 has been selected (or e.g.
assuming that licensee user terminal 410 has not been selected if
no control signaling is received.)
[0140] If baseband processing circuit 416 determines in 706 that
licensee user terminal has not been assigned as a measurement
terminal, baseband processing circuit 416 may proceed to 710 to
receive a shared spectrum uplink allocation via control signaling
from licensee base station 310 (as previously detailed regarding
614). Baseband processing circuit 416 may then in 712 perform
uplink communications according to the shared spectrum allocation
received in 710, which may include utilizing shared spectrum for
uplink, utilizing shared spectrum for uplink according to a shared
spectrum uplink transmit power threshold specified by licensee base
station 310, or not utilizing shared spectrum for uplink. It is
again noted that licensee user terminal 310 may additionally be
able to utilize shared spectrum for downlink and dedicated licensed
spectrum for uplink and/or downlink.
[0141] If baseband processing circuit 416 determines in 706 that
licensee user terminal 410 has been selected as measurement
terminal, baseband processing circuit 416 may need to perform
shared spectrum uplink interference estimations and report the
shared spectrum uplink interference estimations to licensee base
station 310. Accordingly, baseband processing circuit 416 may
identify in 706 via control signaling a request for shared spectrum
uplink interference estimations from licensee base station 310,
which may specify either single-instance estimations, periodic
estimations, or autonomous estimations. As licensee user terminal
410 is likely located proximate to the incumbent cell by virtue of
selection as a measurement terminal, it may be unlikely that
licensee user terminal 410 will be allocated any uplink
transmission resources. However, it is nevertheless recognized that
such may be possible (such as if interference to the incumbent is
very low), and accordingly baseband processing circuit 416 may
obtain a shared spectrum uplink allocation from licensee base
station 310 that baseband processing circuit 416 may utilize to
perform uplink transmissions on shared spectrum. While not
explicitly depicted in FIG. 7, licensee user terminal 410 may
additionally perform uplink and downlink communication on dedicated
licensed spectrum.
[0142] Baseband processing circuit 416 may then perform the uplink
interference estimation in 708. Baseband processing circuit 416 may
thus attempt to estimate the total interference contributed by all
licensee user terminals that are utilizing shared spectrum for
uplink transmissions. The uplink interference estimation of 708 may
be summarized as follows: [0143] 708a. Perform uplink signal power
measurement [0144] 708b. Perform downlink signal power measurement
[0145] 708c. Perform downlink reference signal power measurement
[0146] 708d. Calculate estimated uplink interference to the
incumbent [0147] 708e. Report estimated uplink interference to
licensee base station
[0148] Accordingly, baseband processing circuit 416 may first
perform an uplink signal power measurement in 708a to obtain the
received uplink signal power P.sub.u (e.g. during a TDD uplink
subframe or on a TDD uplink band), which may include receiving a
time-domain uplink signal y.sub.u(t) given as
y u ( t ) = i = 1 N up h ul i ( t ) x ul i ( t ) + h inc ( t ) x
inc ( t ) + n ( t ) , ( 8 ) ##EQU00003##
with corresponding frequency-domain uplink signal Y.sub.u(f)
Y u ( f ) = i = 1 N up H ul i ( f ) X ul i ( f ) + H inc ( f ) X
inc ( f ) + N ( f ) , ( 9 ) ##EQU00004##
where N.sub.up denotes the number of licensee user terminals using
shared spectrum for uplink, N.sub.ul.sup.i(t) and H.sub.ul.sup.i(f)
respectively denote the impulse response and channel response
between the i-th uplink licensee user terminal and licensee user
terminal 410, x.sub.ul.sup.i (t) and H.sub.ul.sup.i(f) respectively
denote the time-domain and frequency-domain uplink signal
transmitted by the i-the uplink licensee user terminal.
[0149] The received uplink signal power P.sub.u is thus given
as
P.sub.u=P.sub.ul+P.sub.inc+P.sub.n, (10)
where P.sub.ul is the uplink interference, P.sub.inc is the
received incumbent signal power, and P.sub.n is the received noise
signal power (both as introduced in Equation (3)).
[0150] Baseband processing circuit 416 may additionally perform a
downlink signal power measurement in 708b to obtain the downlink
signal power P.sub.d (as detailed regarding Equation (3) and 704c).
Baseband processing circuit 416 may either utilize the same
downlink signal power measurement for P.sub.d obtained in 704c or
may alternatively perform an updated downlink signal power
measurement to obtain P.sub.d.
[0151] Baseband processing circuit 416 may additionally perform a
downlink reference signal power measurement in 708c to obtain a
downlink reference signal power estimate {circumflex over
(P)}.sub.rs as detailed regarding Equation (6) and 704e. Baseband
processing circuit 416 may either obtain an updated downlink
reference signal power estimate {circumflex over (P)}.sub.rs (e.g.
based on an updated received downlink signal y.sub.a (t) and
Y.sub.d(f)) or may alternatively utilize the downlink reference
signal power estimate {circumflex over (P)}.sub.rs obtained in
704e.
[0152] Baseband processing circuit 416 may then obtain an uplink
interference estimate {circumflex over (P)}.sub.ul that
approximates P.sub.ul from Equation (10) using P.sub.d, P.sub.u,
and {circumflex over (P)}.sub.rs as obtained in 708a-708c.
Specifically, baseband processing circuit 416 may calculate
{circumflex over (P)}.sub.ul in 708d as
P ^ ul = P u + P ^ rs - P d = P ul + P inc + P n + P ^ rs - P rs -
P inc - P n = P ul + P ^ rs - P rs , ( 11 ) ##EQU00005##
i.e. by subtracting the received downlink signal power P.sub.d from
the received uplink signal power P.sub.u and adding the downlink
reference signal power estimation {circumflex over (P)}.sub.rs.
[0153] Assuming an accurate estimation for P.sub.rs in {circumflex
over (P)}.sub.rs, baseband processing circuit 416 may obtain
{circumflex over (P)}.sub.ul.apprxeq.P.sub.ul in 708d. Baseband
processing circuit 416 may thus obtain an estimate for the
interference to the incumbent caused by uplink transmissions of
licensee user terminals in 708, which baseband processing circuit
416 may subsequently report to licensee base station 310 in 708e.
Each measurement terminal may equivalently calculate and report
uplink interference estimations to licensee base station 310, which
(as detailed in regarding 610-614) licensee base station 310 may
utilize the uplink interference estimations to evaluate the current
levels of uplink interference and decide whether shared spectrum
uplink power control is necessary.
[0154] Accordingly, licensee base station 310 may be able to select
appropriate licensee user terminals to use as measurement terminals
and perform shared spectrum uplink power control procedures based
on incumbent signal power estimations reported by the licensee user
terminals.
[0155] In the procedures detailed above in FIG. 5 and FIG. 6,
licensee base station 310 may request that each licensee user
terminal perform and report incumbent signal power estimates (in
602-604 and 702-704). However, the calculations in 704a-704f may
require appreciable computational power and thus may result in a
large power penalty for each licensee user terminal.
[0156] In order to reduce power consumption at the licensee user
terminals, licensee base station 310 may instead make a
"preliminary" selection of licensee user terminals to request
incumbent signal power estimates from. In particular, licensee base
station 310 may require licensee user terminals to report downlink
channel conditions, which may be specified as part of a wireless
communication protocol (e.g. LTE, UMTS, GSM, CDMA, etc.).
Accordingly, the licensee user terminals may be required to measure
downlink reference signals and provide corresponding downlink
reference signal power measurements to licensee base station
310.
[0157] FIG. 8 shows message sequence chart 800 that illustrates a
preliminary selection of licensee user terminals by licensee base
station 310.
[0158] In 802, licensee base station 310 may perform a downlink
transmission, which may include a downlink reference signal (e.g.
PSS, SSS, CRS, etc.). Each licensee user terminal may receive the
downlink transmission and perform a downlink reference signal power
estimation at 804 (e.g. at baseband processing circuit 416 as
detailed regarding Equation (6) and 704a-704e). As previously
indicated, the wireless communication protocol utilized by licensee
base station 310 and the licensee user terminals may require the
licensee user terminals to periodically estimate and report
received downlink reference signal power. Accordingly, the licensee
user terminals may perform the downlink signal power estimate in
804 and subsequently report the downlink signal power estimate in
806 as part of the wireless communication protocol, such as via a
measurement procedure report.
[0159] Licensee base station 310 (uplink control circuit 318) may
then rank the licensee user terminals according to reported
downlink reference signal power in 808, such as in ascending order
by ranking the licensee user terminals that report the strongest
downlink signal power estimates the highest and the licensee user
terminals that report the weakest downlink signal power estimates
the lowest. Analogously to as detailed above regarding received
incumbent signal power, licensee base station 310 may characterize
the licensee user terminals that report the strongest downlink
signal power estimates as being located the closest to licensee
base station 310 and conversely characterize the licensee user
terminals that report the weakest downlink signal power estimates
as being located the furthest from licensee base station 310.
[0160] Accordingly, licensee base station 310 may be able to
determine which of the licensee user terminals are located at the
cell edge based on the ranking obtained in 808 (and may
additionally compare reported downlink reference signal power
estimates to a predetermined signal power threshold to further
identify cell-edge terminals). By identifying which of the licensee
user terminals are closest to the cell edge, licensee base station
310 may obtain a preliminary selection of licensee user terminals
that would be suitable for either measurement terminal selection or
shared spectrum uplink usage. Specifically, licensee base station
310 may wish to select only the licensee user terminals that are
located closest to the incumbent cell as measurement terminals (as
shown in FIG. 5), which accordingly may be located at the cell edge
of the licensee cell. Licensee base station 310 may thus
preliminarily select the cell-edge terminals identified in 808 for
eligibility in measurement terminal selection.
[0161] Similarly, licensee base station 310 may wish to select
licensee user terminals on the opposite edge of the licensee to
allow to utilize shared spectrum for uplink, as these licensee user
terminals may be located furthest from the incumbent cell and thus
will contribute the least to uplink interference to the
incumbent.
[0162] While licensee base station 310 may be able to identify the
cell-edge licensee user terminals based on reported downlink
reference signal power estimates, licensee base station 310 may not
be able to identify exactly where on the cell-edge each licensee
user terminal is located, and accordingly may not be able to select
measurement terminals or allocate shared spectrum uplink power
usage solely based on reported downlink reference signal power
estimates.
[0163] Licensee base station 310 (uplink control circuit 318) may
then assign the cell-edge licensee user terminals to estimate the
incumbent signal power in 810. Accordingly, some of the licensee
user terminals (identified as cell-edge terminals in 808) may be
assigned to estimate the incumbent signal power while others (not
identified as cell-edge terminals in 808) may not be assigned to
estimate the incumbent signal power. Accordingly, the licensee user
terminals that are not assigned to estimate the incumbent signal
power may not need to perform the incumbent signal power
calculations or reporting of 704a-704g, and accordingly may save
power; however, as these licensee user terminals do not report
incumbent signal power estimates licensee base station 310 may not
be able to consider these licensee user terminals as measurement
terminals and/or for shared spectrum uplink usage.
[0164] Accordingly, the licensee user terminals assigned for
incumbent signal power estimation may estimate the incumbent signal
power in 812 (704a-704g) and report the incumbent signal power
estimates to licensee base station 310 at 814. The remaining
licensee use terminals not assigned for incumbent signal power
estimation may be assigned as other licensee user terminals as 822,
which may not be measurement terminals and may not use shared
spectrum for uplink activity (although may still utilize shared
spectrum for downlink and/or dedicated licensed spectrum for uplink
and downlink).
[0165] Licensee base station 310 (uplink control circuit 318) may
then rank the cell-edge user terminals according to reported
incumbent signal power estimates in 816, such as by ranking the
cell-edge user terminals that report the strongest incumbent signal
power estimates the highest and ranking the cell-edge user
terminals that report the weakest incumbent signal power estimates
the lowest. Licensee base station 310 may thus identify the
cell-edge user terminals that report the strongest incumbent signal
power estimates as being located closest to the incumbent while
identifying the cell-edge user terminals that report the weakest
incumbent signal power estimates as being located the furthest from
the incumbent.
[0166] Accordingly, licensee base station 310 (uplink control
circuit 318) may identify the cell-edge user terminals that report
the weakest incumbent signal power estimates as licensee user
terminals that are permitted to utilize shared spectrum for uplink
and subsequently assign these licensee user terminal to utilize
shared spectrum for uplink in 818. Licensee base station 310 may
identify the cell-edge licensee user terminals that report the
strongest incumbent signal power estimates as the measurement
terminals and subsequently assign these licensee user terminals as
measurement terminals in 820.
[0167] Each licensee user terminal may thus be assigned as either a
measurement terminal at 826, a shared spectrum licensee user
terminal at 824, or an "other" licensee user terminal at 822 (not
shared spectrum uplink and not a measurement terminal).
[0168] The measurement terminals may thus estimate the uplink
interference to the incumbent in 828 (708a-708d) and report the
estimated incumbent signal power to licensee base station in 832
(708e), which licensee base station 310 may utilize for shared
spectrum uplink power allocation.
[0169] The shared spectrum uplink terminals may be allowed to
utilize shared spectrum for uplink in 830, and accordingly may
begin uplink transmission on shared spectrum. Depending on the
uplink interference estimates reported by the measurement terminals
in 832, licensee base station 310 may adjust the shared spectrum
uplink power allocation for the shared spectrum uplink terminals,
such as by disabling shared spectrum uplink and/or reducing the
permitted shared spectrum uplink transmit power as part of shared
spectrum uplink power control procedures.
[0170] The other licensee user terminals may not be measurement
terminals and may not be allowed to utilize shared spectrum for
uplink, and accordingly may utilize dedicated licensed spectrum for
uplink and downlink potentially in addition to shared spectrum for
downlink. If licensee base station 310 determines that the uplink
interference to the incumbent is appreciably within acceptable
levels, licensee base station 310 may at a later time permit one or
more of the other licensee user terminals to utilize shared
spectrum for uplink (which may optionally also include requesting
incumbent signal power estimates from the other licensee user
terminals to allow licensee base station 310 to identify other
licensee user terminals located far from the incumbent cell that
may be suitable for shared spectrum uplink usage).
[0171] Licensee base station 310 may alternatively only select
licensee user terminals that wish to be allocated uplink resources
as measurement terminals and/or shared spectrum uplink terminals.
For example, only some of the licensee user terminals may have
requested uplink resources from licensee base station 310 (e.g. via
control signaling), and accordingly the remaining licensee user
terminals may only require downlink resources (either in a radio
active state or a radio idle state). Accordingly, licensee base
station 310 may only consider the licensee user terminals that have
requested uplink resources for measurement terminals and/or shared
spectrum uplink, and accordingly may allow the remaining licensee
user terminals to conserve power by avoiding any incumbent signal
power and/or uplink interference estimate calculations.
[0172] Accordingly, licensee base station 310 may rely on incumbent
signal power estimates reported by licensee user terminals in order
to identify measurement terminals and/or perform shared spectrum
uplink allocations. Licensee base station 310 may additionally
employ reported downlink reference signal estimates to tentatively
identify eligible measurement and shared spectrum uplink terminals,
which may conserve power at certain licensee user terminals as
these licensee user terminals may not need to calculate or report
incumbent signal power.
[0173] Furthermore, certain calculations detailed as being
performed by a licensee user terminal (e.g. baseband processing
circuit 416) in 704 and 708 may alternatively be performed by
licensee base station 310. For example, a licensee user terminal
such as licensee user terminal 410 may receive downlink and/or
uplink signals and report signal power estimates back to licensee
base station 310, which may subsequently (at uplink control circuit
318) perform some or all of the calculations detailed in 704 and/or
708 in order to obtain incumbent signal power and uplink
interference estimates. Furthermore, licensee user terminals may
utilize device-to-device communication schemes such as Proximity
Services (ProSe, also known as D2D), WiFi Direct, or Bluetooth, in
order to aggregate calculations. For example, one or more mobile
terminals may provide a specific mobile terminal with obtained
signal power measurements needed for incumbent signal power and/or
uplink interference calculations. The specific mobile terminal may
then perform the calculations for the one or more mobile terminals,
which may include averaging or aggregating (including selecting a
single value to report) signal power measurements and/or
calculation results, and report the resulting individual or
aggregated measurements to licensee base station 310. Such may
allow the one or more mobile terminals to offload processing in
order to conserve power.
[0174] Additionally, while the uplink control processing at a
licensee base station has been detailed above as being performed by
an uplink control circuit located at the licensee base station,
some or all of the processing may be performed at a separate
component located in the core network that is interfaced with
licensee base station 310. For example, an LSA or SAS entity may be
interfaced with licensee base station 310, and licensee base
station 310 may provide various signal power and interference
measurements to this LSA or SAS entity. The LSA or SAS entity may
then perform the requisite processing (e.g. to identify measurement
terminals and/or to determine appropriate shared spectrum uplink
power allocation measures) and provide the results to licensee base
station 310. It is thus not limited that the uplink control circuit
be located at a single licensee base station.
[0175] It is noted that FIG. 5 depicts a simplified scenario in
which a single incumbent cell is located proximate to a single
licensee cell. In actual implementations, more than one incumbent
cell may be located proximate to a licensee cell, which may affect
the incumbent signal power measurements reported to licensee base
station 310 by the licensee user terminals. Licensee base station
310 may nevertheless adopt an equivalent approach in selecting
measurement terminals and allocating shared spectrum uplink based
on incumbent signal power estimates reported by the licensee user
terminals. For example, if licensee base station 310 is surrounded
by incumbent cells, licensee base station 310 may select cell-edge
terminals on all sides as measurement terminals as such cell-edge
terminals will report strong incumbent signal power estimates due
to the proximity to one or more of the surrounding incumbent cells.
Licensee base station 310 may additionally allocate higher shared
spectrum uplink transmit powers to licensee user terminals located
proximate to licensee base station 310 (e.g. at the center of the
licensee cell) as such licensee user terminals may be the furthest
from the surrounding incumbent cells.
[0176] Similarly, an implemented spectrum sharing scheme may
provide multiple shared spectrum bands, e.g. where licensee base
station 310 shares multiple frequency bands with one or more
incumbents. The procedures detailed above may equivalently be
applied to each individual shared spectrum band, and may
additionally allow for licensee base station 310 to switch licensee
user terminals between shared spectrum bands in order to better
manage uplink interference.
[0177] FIG. 9 shows method 900 at a control device of a first
wireless network. As shown in FIG. 9, method 900 includes
estimating a proximity to a second wireless network for each of a
plurality of user terminals based on a measurement of the second
wireless network reported by each of the plurality of user
terminals (910), selecting one or more measurement terminals from
the plurality of user terminals based on the estimated proximity of
each of the plurality of user terminals (920), and receiving one or
more interference measurements from the one or more measurement
terminals that indicate interference to the second wireless network
caused by the first wireless network (930).
[0178] In one or more further exemplary aspects of the disclosure,
one or more of the features described above in reference to FIGS.
1-8 may be further incorporated into method 900. In particular,
method 900 may be configured to perform further and/or alternate
processes as detailed regarding licensee base station 310 and/or
uplink control circuit 318.
[0179] FIG. 10 shows method 1000 at a control device of a first
wireless network. As shown in FIG. 10, method 1000 includes
estimating a proximity to a second wireless network for each of a
plurality of user terminals based on a measurement of the second
wireless network reported by each of the plurality of user
terminals (1010), determining whether the second wireless network
is experiencing excessive interference from the first wireless
network (1020), and if the second wireless network is experiencing
excessive interference from the first wireless network, adjusting a
transmit power allocation of one or more selected user terminals of
the plurality of user terminals based on the estimated proximity to
the second wireless network for each of the one or more selected
user terminals (1030).
[0180] In one or more further exemplary aspects of the disclosure,
one or more of the features described above in reference to FIGS.
1-8 may be further incorporated into method 1000. In particular,
method 1000 may be configured to perform further and/or alternate
processes as detailed regarding licensee base station 310 and/or
uplink control circuit 318.
[0181] FIG. 11 shows method 1100 at a user terminal. As shown in
FIG. 11, method 1100 includes receiving a composite signal
including a first received signal from a first wireless network and
a second received signal from a second wireless network (1110),
calculating a correlation between the composite signal and a local
reference signal to determine a signal power measurement of the
second received signal (1120), reporting the signal power
measurement to the first wireless network as a measurement report
(1130), and receiving control signaling in response to the
measurement report that specifies an assigned operation
configuration for the user terminal (1140).
[0182] In one or more further exemplary aspects of the disclosure,
one or more of the features described above in reference to FIGS.
1-8 may be further incorporated into method 1100. In particular,
method 1100 may be configured to perform further and/or alternate
processes as detailed regarding licensee user terminal 410 and/or
baseband processing circuit 416.
[0183] The above description may thus relate to interference
between two (or more) networks, which may include two networks of
the same radio access technology or two networks of different radio
access technologies. The networks may each operate on available
spectrum, which may be the overall pool of spectral radio resources
(by frequency) available to the networks. The spectrum available to
each network may be different, and may include both exclusive
spectrum (e.g. only available to certain network operators based on
licensing) and non-exclusive spectrum (e.g. available to more than
one network operator). The available spectrum may be shared between
two (or more) networks, such as according to the spectrum sharing
systems detailed herein, which may include spectrum sharing on an
incumbent/licensee basis.
[0184] Furthermore, shared spectrum may be accessed according to a
tier system that defines higher- and lower-tier users, which may
range (in order from high to low) in e.g. LSA from incumbent to
licensee users and in e.g. SAS from incumbent users to priority
users (e.g. PAL users) to general users (e.g. GAA users). The
shared spectrum allocated may be dynamic, and accordingly may be
dynamically reassigned by a controller entity (e.g. LSA controller,
SAS entity, etc.) between incumbents and various tiered licensee
users. The shared spectrum may be specified as spectrum
information, which may include specific frequency bands.
[0185] The various users in shared spectrum schemes may need to
consider interference levels, in particular between licensee users
and incumbents, which may include licensee users monitoring the
level of interference to an incumbent in order to ensure that the
interference remains below certain levels. Certain networks may
cause interference to other networks, which may occur when radio
activity by a first network interrupts, obstructs, or degrades
radio activity of at least a second network. Accordingly, licensee
users may have an interference level allowance that dictates a
permitted level of interference to an incumbent. Such interference
level allowances may be stored in a storage element responsible for
holding and providing interference level allowances, which may be
dynamic and thus may change over time. Such storage elements may be
located within licensee networks within incumbent networks, and/or
separately from both licensee and incumbent networks, which may
include storage elements located within SAS and/or LSA components
(such as e.g. LSA controllers and SAS entities).
[0186] While the above description has focused on LSA and SAS
spectrum sharing systems, further bands may also emerge as
candidates for spectrum sharing, including in particular frequency
bands under 6 GHz traditionally utilized for wireless
communications as well as centimeter- and millimeter-wavelength
bands above 6 GHz. Accordingly, the descriptions herein are
considered demonstrative in nature and may be analogously applied
to any spectrum sharing scheme independent of the particular
frequency bands targeted for sharing.
[0187] The above description includes references related to a
"proximity to a wireless network", such as in the incumbent cell
distance employed by uplink control circuit 318. Such a proximity
to a wireless network includes i) the minimum geographic distance
of users from one network (network "A") to users of another network
(network "B"). Then, the "distance between both networks"
corresponds to the geographic distance of those two users (one from
network "A" and the other one from network "B") such that the
distance becomes minimum, ii) the average distance of a sub-set of
users from network "A" and network "B" is considered, typically the
subset is chosen such that the distances between users from the
"network "A" subset" and the "network "B" subset" are minimum, iii)
any other sub-set of users may be taken from network "A" and
network "B" based on metrics such as geographic distance, signal
strength at the BS/AP of network "A" and/or network "B" or other
network nodes, geographic distance from serving/neighboring BS/AP,
etc., iv) the distance of users from network "A" (and "B") and
their respective distance to their respective serving BS/AP.
[0188] Those users with large distance to the serving BS/AP are
considered to be at the cell edge and those close to a neighboring
cell, a specific neighboring cell may be identified through
calculation of an angle of a connecting line between the concerned
user device and its serving cell, v) the users of a cell may be
split into a hierarchy of sub-sets, e.g. users with the largest
distance from the serving BS/AP may be part of the tier-1
hierarchy, users with a medium distance from the serving BS/AP may
be part of the tier-2 hierarchy, users with the smallest distance
from the serving BS/AP may be part of the tier-3 hierarchy; then,
the average distance of users from selected tiers between two
neighboring cells is calculated. Distances can be determined for
example by measuring the propagation delay, by considering the
propagation delay of the strongest signal components in a multipath
propagation environment (requires the derivation of the channel
impulse response), etc.
[0189] Furthermore, licensees in spectrum sharing schemes may not
be limited to MNOs, and accordingly a licensee may refer to any
entity that licenses spectrum in spectrum sharing scheme.
Additionally, the interference mitigation detailed herein may be
applied to any two or more networks (e.g. the incumbent network and
the licensee network included in wireless network 300), where the
two or more networks may utilize the same RAT or different RATS.
Furthermore, the two or more networks may be party of a priority
hierarchy, such as where a first network has a higher priority than
a second network and accordingly interference from the second
network onto the first network may need to be minimized/kept below
a (predefined) threshold/prevented/reduced/etc.
[0190] It is appreciated that the terms "user equipment", "UE",
"mobile terminal", etc., may apply to any wireless communication
device, including cellular phones, tablets, laptops, personal
computers, and any number of additional electronic devices capable
of wireless communications.
[0191] It is appreciated that implementations of methods detailed
herein are demonstrative in nature, and are thus understood as
capable of being implemented in a corresponding device. Likewise,
it is appreciated that implementations of devices detailed herein
are understood as capable of being implemented as a corresponding
method. It is thus understood that a device corresponding to a
method detailed herein may include a one or more components
configured to perform each aspect of the related method.
[0192] All acronyms defined in the above description additionally
hold in all claims included herein.
[0193] The following examples pertain to further aspects of the
disclosure:
[0194] Example 1 is a method at a control device of a first
wireless network for obtaining interference measurements, the
method including estimating a proximity to a second wireless
network for a plurality of user terminals based on a measurement of
the second wireless network reported by the plurality of user
terminals, selecting one or more measurement terminals from the
plurality of user terminals based on the estimated proximity of the
plurality of user terminals, and receiving one or more interference
measurements from the one or more measurement terminals that
indicate interference to the second wireless network related to the
first wireless network.
[0195] In Example 2, the subject matter of Example 1 can optionally
include wherein the first wireless network and the second wireless
network operate on a shared frequency band.
[0196] In Example 3, the subject matter of Example 1 or 2 can
optionally include wherein selecting one or more measurement
terminals from the plurality of user terminals based on the
estimated proximity of the plurality of user terminals includes
selecting one or more of the plurality of user terminals that
report the strongest measurements of the second wireless network as
the one or more measurement terminals.
[0197] In Example 4, the subject matter of any one of Examples 1 to
3 can optionally include wherein estimating a proximity to a second
wireless network for a plurality of user terminals based on a
measurement of the second wireless network reported by the
plurality of user terminals includes determining that one or more
first user terminals of the plurality of user terminals that report
strong measurements are located closer to the second wireless
network than one or more second user terminals of the plurality of
user terminals that report weak measurements.
[0198] In Example 5, the subject matter of any one of Examples 1 to
4 can optionally further include receiving the measurement of the
second wireless network from each respective user terminal of the
plurality of user terminals.
[0199] In Example 6, the subject matter of Example 1 can optionally
include wherein estimating a proximity to a second wireless network
for a plurality of user terminals based on a measurement of the
second wireless network reported by the plurality of user terminals
includes estimating the proximity to the second wireless network
for the plurality of user terminals relative to the proximity of
the other user terminals of the plurality of user terminals to the
second wireless network based on the measurement of the second
wireless network reported by the plurality of user terminals.
[0200] In Example 7, the subject matter of Example 1 can optionally
include wherein the measurement of the second wireless network
reported by the plurality of user terminals is a signal power
measurement of the second wireless network, and wherein estimating
a proximity to a second wireless network for a plurality of user
terminals based on a measurement of the second wireless network
reported by the plurality of user terminals includes ranking the
plurality of user terminals in order according to the signal power
measurement reported by the plurality of user terminals.
[0201] In Example 8, the subject matter of Example 1 can optionally
include wherein the measurement of the second wireless network
reported by the plurality of user terminals is a signal power
measurement of the second wireless network, and wherein estimating
a proximity to a second wireless network for a plurality of user
terminals based on a measurement of the second wireless network
reported by the plurality of user terminals includes at least one
of ranking the plurality of user terminals according to the signal
power measurement reported by the plurality of user terminals,
comparing a signal power measurement reported by a first user
terminal of the plurality of user terminals to a signal power
measurement reported by a second user terminal of the plurality of
user terminals, comparing the signal power measurement reported by
the plurality of user terminals to a signal power threshold, or
calculating an approximate proximity from the second wireless
network based on the signal power measurement.
[0202] In Example 9, the subject matter of Example 1 can optionally
further include estimating a proximity to a transmission point of
the first wireless network of a further plurality of user terminals
based on a measurement of the transmission point reported by the
further plurality of user terminals, and selecting the plurality of
user terminals from the further plurality of user terminals based
on the estimated proximity of the further plurality of user
terminals from the transmission point.
[0203] In Example 10, the subject matter of Example 9 can
optionally further include selecting the user terminals of the
further plurality of user terminals that have the farthest
estimated proximity from the transmission point as the plurality of
user terminals.
[0204] In Example 11, the subject matter of any one of Examples 1
to 10 can optionally further include determining whether to perform
uplink power control based on the one or more interference
measurements.
[0205] In Example 12, the subject matter of Example 11 can
optionally include wherein determining whether to perform uplink
power control based on the one or more interference measurements
includes determining to perform uplink power control if the one or
more interference measurements indicate excessive interference to
the second wireless network.
[0206] In Example 13, the subject matter of Example 12 can
optionally further include selecting one or more target user
terminals from the plurality of user terminals to reduce allocated
uplink transmit power based on the estimated proximity of the one
or more target user terminals from the second wireless network.
[0207] In Example 14, the subject matter of Example 15 can
optionally further include transmitting control signaling to the
one or more target terminals that specifies a reduction in uplink
transmit power allocation.
[0208] In Example 15, the subject matter of Example 11 can
optionally include wherein determining whether to perform uplink
power control based on the one or more interference measurements
includes comparing the one or more interference measurements to a
predetermined interference threshold, and determining to perform
uplink power control if the one or more interference measurements
satisfy the predetermined interference threshold.
[0209] In Example 16, the subject matter of Example 15 can
optionally include wherein the first wireless network is a licensee
in a spectrum sharing system and the second wireless network is an
incumbent in the spectrum sharing system, and wherein the
predetermined interference threshold is based on an incumbent
protection interference threshold of the spectrum sharing
system.
[0210] In Example 17, the subject matter of Example 16 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system and the incumbent
protection interference threshold is an interference threshold for
the protection zone.
[0211] In Example 18, the subject matter of Example 15 can
optionally include wherein determining whether to perform uplink
power control based on the one or more interference measurements
further includes determining not to perform uplink power control if
the one or more interference measurements is below the
predetermined interference threshold.
[0212] In Example 19, the subject matter of any one of Examples 1
to 18 can optionally include wherein the measurement of the second
wireless network reported by a first user terminal of the plurality
of user terminals is a signal power measurement that indicates a
signal power of a signal received by the first user terminal from
the second wireless network.
[0213] In Example 20, the subject matter of any one of Examples 1
to 19 can optionally include wherein the plurality of user
terminals utilize a first radio frequency band that overlaps with a
second radio frequency band utilized by the second wireless
network.
[0214] In Example 21, the subject matter of any one of Examples 1
to 20 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network.
[0215] In Example 22, the subject matter of any one of Examples 1
to 21 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network as
part of a spectrum sharing system.
[0216] In Example 23, the subject matter of any one of Examples 1
to 22 can optionally include wherein the first wireless network is
a licensee in a spectrum sharing system and the second wireless
network is an incumbent in the spectrum sharing system.
[0217] In Example 24, the subject matter of Example 23 can
optionally include wherein the spectrum sharing system is a
Licensed Shared Access (LSA) system or a Spectrum Access System
(SAS) system.
[0218] In Example 25, the subject matter of Example 23 or 24 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system.
[0219] In Example 26, the subject matter of any one of Examples 1
to 25 can optionally include wherein the control device is a base
station of the first wireless network.
[0220] In Example 27, the subject matter of any one of Examples 1
to 25 can optionally include wherein the control device is located
at a base station of the first wireless network.
[0221] In Example 28, the subject matter of any one of Examples 1
to 27 can optionally include wherein the first wireless network is
operated by a different network operator than the second wireless
network.
[0222] Example 29 is a network control device including a network
control circuit configured to perform the method of any one of
Examples 1 to 28.
[0223] Example 30 is a base station device including a network
control circuit configured to perform the method of any one of
Examples 1 to 28.
[0224] Example 31 is a non-transitory computer readable medium
storing instructions which when executed by a processor control the
processor to perform the method of any one of Examples 1 to 28.
[0225] Example 32 is a method at a control device of a first
wireless network for performing transmission power control, the
method including estimating a proximity to a second wireless
network for a plurality of user terminals based on a measurement of
the second wireless network reported by the plurality of user
terminals, determining whether the second wireless network is
experiencing excessive interference from the first wireless
network, and if the second wireless network is experiencing
excessive interference from the first wireless network, adjusting a
transmit power allocation of one or more selected user terminals of
the plurality of user terminals based on the estimated proximity to
the second wireless network for the one or more selected user
terminals.
[0226] In Example 33, the subject matter of Example 32 can
optionally include wherein the first wireless network and the
second wireless network operate on a shared frequency band.
[0227] In Example 34, the subject matter of Example 32 or 33 can
optionally further include if the second wireless network is not
experiencing excessive interference from the first wireless
network, performing one of maintaining the transmit power
allocation of the one or more selected user terminals, or
increasing the transmit power allocation of one or more further
user terminals of the plurality of user terminals.
[0228] In Example 35, the subject matter of Example 34 can
optionally include wherein increasing the transmit power allocation
of one or more further user terminals of the plurality of user
terminals includes selecting one or more user terminals of the
plurality of user terminals that have far estimated proximities to
the second wireless network as the one or more further user
terminals.
[0229] In Example 36, the subject matter of Example 32 can
optionally further include selecting the one or more selected user
terminals from the plurality of user terminals based on which of
the plurality of user terminals have close estimated proximities to
the second wireless network.
[0230] In Example 37, the subject matter of Example 32 can
optionally include wherein adjusting a transmit power allocation of
one or more selected user terminals of the plurality of user
terminals based on the estimated proximity to the second wireless
network for the one or more selected user terminals includes
selecting one or more user terminals of the plurality of user
terminals that have close estimated proximities to the second
wireless network as the one or more selected user terminals, and
reducing the transmit power allocation of the one or more selected
user terminals.
[0231] In Example 38, the subject matter of Example 32 can
optionally include wherein adjusting a transmit power allocation of
one or more selected user terminals of the plurality of user
terminals based on the estimated proximity to the second wireless
network for the one or more selected user terminals includes
selecting one or more user terminals of the plurality of user
terminals that have close estimated proximities to the second
wireless network as the one or more selected user terminals, and
allocating zero uplink transmit power for the one or more selected
user terminals.
[0232] In Example 39, the subject matter of any one of Examples 32
to 38 can optionally further include receiving one or more
interference measurements from one or more measurement terminals,
and wherein determining whether the second wireless network is
experiencing excessive interference from the first wireless network
includes determining whether the second wireless network is
experiencing excessive interference from the first wireless network
based on the one or more interference measurements.
[0233] In Example 40, the subject matter of Example 39 can
optionally include wherein the one or more measurement terminals
are user terminals of the plurality of user terminals.
[0234] In Example 41, the subject matter of Example 39 can
optionally further include selecting one or more measurement
terminals from the plurality of user terminals, and receiving one
or more one or more interference measurements from one or more
measurement terminals, and wherein determining whether the second
wireless network is experiencing excessive interference from the
first wireless network includes determining whether the second
wireless network is experiencing excessive interference from the
first wireless network based on the one or more interference
measurements.
[0235] In Example 42, the subject matter of Example 41 can
optionally include wherein determining whether the second wireless
network is experiencing excessive interference from the first
wireless network based on the one or more interference measurements
includes determining whether the one or more interference
measurements satisfy predetermined interference criteria.
[0236] In Example 43, the subject matter of Example 42 can
optionally include wherein the first wireless network is a licensee
in a spectrum sharing system and the second wireless network is an
incumbent in the spectrum sharing system, and wherein the
predetermined interference criteria is interference criteria of the
spectrum sharing system.
[0237] In Example 44, the subject matter of Example 42 can
optionally include wherein the first wireless network operates in a
protection zone of the spectrum sharing system, and wherein the
predetermined interference criteria is protection zone interference
criteria.
[0238] In Example 45, the subject matter of Example 41 can
optionally include wherein determining whether the second wireless
network is experiencing excessive interference from the first
wireless network based on the one or more interference measurements
includes comparing the one or more interference measurements to a
predetermined interference threshold.
[0239] In Example 46, the subject matter of Example 45 can
optionally include wherein the first wireless network is a licensee
in a spectrum sharing system and the second wireless network is an
incumbent in the spectrum sharing system, and wherein the
predetermined interference threshold is an interference threshold
of the spectrum sharing system.
[0240] In Example 47, the subject matter of Example 41 can
optionally include wherein selecting one or more measurement
terminals from the plurality of user terminals includes selecting
the one or more measurement terminals from the plurality of user
terminals based on the estimated proximity to the second wireless
network for the one or more measurement terminals.
[0241] In Example 48, the subject matter of Example 47 can
optionally include wherein selecting the one or more measurement
terminals from the plurality of user terminals based on the
estimated proximity to the second wireless network for the one or
more measurement terminals includes selecting one or more user
terminals of the plurality of user terminals that have the closest
estimated proximities to the second wireless network of the
plurality of user terminals as the one or more measurement
terminals.
[0242] In Example 49, the subject matter of any one of Examples 32
to 48 can optionally include wherein adjusting a transmit power
allocation of one or more selected user terminals of the plurality
of user terminals based on the estimated proximity to the second
wireless network for the one or more selected user terminals
includes transmitting control signaling to the one or more selected
user terminals that specifies an adjustment in transmit power
allocation.
[0243] In Example 50, the subject matter of any one of Examples 32
to 49 can optionally include wherein adjusting a transmit power
allocation of one or more selected user terminals of the plurality
of user terminals based on the estimated proximity to the second
wireless network for the one or more selected user terminals
includes selecting one or more user terminals of the plurality of
user terminals that report the strongest measurements of the second
wireless network as the one or more selected terminals, and
reducing the transmit power allocation of the one or more selected
user terminals.
[0244] In Example 51, the subject matter of Example 32 can
optionally include wherein estimating a proximity to a second
wireless network for a plurality of user terminals based on a
measurement of the second wireless network reported by the
plurality of user terminals includes determining that one or more
first user terminals of the plurality of user terminals that report
strong measurements of the second wireless network are located
closer to the second wireless network than one or more second user
terminals of the plurality of user terminals that report weak
measurements of the second wireless network.
[0245] In Example 52, the subject matter of Example 32 can
optionally include wherein estimating a proximity to a second
wireless network for a plurality of user terminals based on a
measurement of the second wireless network reported by the
plurality of user terminals includes estimating the proximity to
the second wireless network for the plurality of user terminals
relative to the proximity of the other user terminals of the
plurality of user terminals to the second wireless network based on
the measurement of the second wireless network reported by the
plurality of user terminals.
[0246] In Example 53, the subject matter of Example 32 can
optionally include wherein the measurement of the second wireless
network reported by the plurality of user terminals is a signal
power measurement of the second wireless network, and wherein
estimating a proximity to a second wireless network for a plurality
of user terminals based on a measurement of the second wireless
network reported by the plurality of user terminals includes
ranking the plurality of user terminals in order according to the
signal power measurement reported by the plurality of user
terminals.
[0247] In Example 54, the subject matter of Example 32 can
optionally include wherein the measurement of the second wireless
network reported by the plurality of user terminals is a signal
power measurement of the second wireless network, and wherein
estimating a proximity to a second wireless network for a plurality
of user terminals based on a measurement of the second wireless
network reported by the plurality of user terminals includes at
least one of ranking the plurality of user terminals according to
the signal power measurement reported by the plurality of user
terminals, comparing a signal power measurement reported by a first
user terminal of the plurality of user terminals to a signal power
measurement reported by a second user terminal of the plurality of
user terminals, comparing the signal power measurement reported by
the plurality of user terminals to a signal power threshold, or
calculating an approximate proximity from the second wireless
network based on the signal power measurement.
[0248] In Example 55, the subject matter of any one of Examples 32
to 54 can optionally include wherein the measurement of the second
wireless network reported by a first user terminal of the plurality
of user terminals is a signal power measurement that indicates a
signal power of a signal received by the first user terminal from
the second wireless network.
[0249] In Example 56, the subject matter of any one of Examples 32
to 55 can optionally include wherein the plurality of user
terminals utilize a first radio frequency band that overlaps with a
second radio frequency band utilized by the second wireless
network.
[0250] In Example 57, the subject matter of any one of Examples 32
to 56 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network.
[0251] In Example 58, the subject matter of any one of Examples 32
to 57 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network as
part of a spectrum sharing system.
[0252] In Example 59, the subject matter of any one of Examples 32
to 58 can optionally include wherein the first wireless network is
a licensee in a spectrum sharing system and the second wireless
network is an incumbent in the spectrum sharing system.
[0253] In Example 60, the subject matter of Example 59 can
optionally include wherein the spectrum sharing system is a
Licensed Shared Access (LSA) system or a Spectrum Access System
(SAS) system.
[0254] In Example 61, the subject matter of Example 59 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system.
[0255] In Example 62, the subject matter of any one of Examples 32
to 61 can optionally include wherein the control device is a base
station of the first wireless network.
[0256] In Example 63, the subject matter of any one of Examples 32
to 62 can optionally include wherein the control device is located
at a base station of the first wireless network.
[0257] In Example 64, the subject matter of any one of Examples 32
to 63 can optionally include wherein the first wireless network is
operated by a different network operator than the second wireless
network.
[0258] Example 65 is a network control device including a network
control circuit configured to perform the method of any one of
Examples 32 to 64.
[0259] Example 66 is a base station device including a network
control circuit configured to perform the method of any one of
Examples 32 to 64.
[0260] Example 67 is a non-transitory computer readable medium
storing instructions which when executed by a processor control the
processor to perform the method of any one of Examples 32 to
64.
[0261] Example 68 is a method at a user terminal for reporting
measurements, the method including receiving a composite signal
including a first received signal from a first wireless network and
a second received signal from a second wireless network,
calculating a correlation between the composite signal and a local
reference signal to determine a signal power measurement of the
second received signal, reporting the signal power measurement to
the first wireless network as a measurement report, and receiving
control signaling in response to the measurement report that
specifies an assigned operation configuration for the user
terminal.
[0262] In Example 69, the subject matter of Example 68 can
optionally include wherein the first wireless network and the
second wireless network operate on a shared frequency band.
[0263] In Example 70, the subject matter of Example 68 or 69 can
optionally include wherein the receiving control signaling in
response to the measurement report that specifies an operation
assignment for the user terminal includes receiving a measurement
operation assignment, the method further including performing an
interference measurement that indicates interference to the second
wireless network, and reporting the interference measurement to the
first wireless network.
[0264] In Example 71, the subject matter of Example 70 can
optionally include wherein the interference measurement indicates
interference to the second wireless network related to the first
wireless network.
[0265] In Example 72, the subject matter of Example 70 can
optionally include wherein performing an interference measurement
that indicates interference to the second wireless network includes
subtracting a downlink reference signal power measurement from an
uplink signal power measurement to obtain a signal power
measurement difference, and subtracting an estimated reference
signal power measurement from the signal power measurement
difference to obtain the interference measurement.
[0266] In Example 73, the subject matter of any one of Examples 68
to 72 can optionally include wherein the receiving control
signaling in response to the measurement report that specifies an
operation assignment for the user terminal includes receiving a
transmit power operation assignment that specifies a transmit
power, the method further including transmitting signals according
to the transmit power.
[0267] In Example 74, the subject matter of any one of Examples 68
to 73 can optionally include wherein calculating a correlation
between the composite signal and a local reference signal to
determine a signal power measurement of the second received signal
includes calculating a cross-correlation between the composite
signal and the local reference signal to obtain the signal power
measurement of the second received signal.
[0268] In Example 75, the subject matter of any one of Examples 68
to 73 can optionally include wherein calculating a correlation
between the composite signal and a local reference signal to
determine a signal power measurement of the second received signal
includes calculating a cross-correlation between the composite
signal and the local reference signal to obtain a reference signal
channel response, calculating a reference signal power measurement
from the reference signal channel response, and subtracting the
reference signal power measurement from a signal power measurement
of the composite signal to obtain the signal power measurement of
the second received signal.
[0269] In Example 76, the subject matter of Example 75 can
optionally include wherein calculating a cross-correlation between
the composite signal and the local reference signal to obtain a
reference signal channel response includes calculating the
cross-correlation between the composite signal and the local
reference signal in the frequency domain to obtain the reference
signal channel response as a reference signal channel frequency
response.
[0270] In Example 77, the subject matter of Example 76 can
optionally include wherein calculating a reference signal power
measurement from the reference signal channel response includes
calculating the reference signal power measurement from the
reference signal channel frequency response.
[0271] In Example 78, the subject matter of any one of Examples 68
to 77 can optionally include wherein the first received signal
includes a downlink reference signal transmitted by a transmission
point of the first wireless network.
[0272] In Example 79, the subject matter of Example 78 can
optionally include wherein receiving a composite signal including a
first received signal from a first wireless network and a second
received signal from a second wireless network includes receiving
the composite signal during a downlink reference signal occasion of
the first wireless network.
[0273] In Example 80, the subject matter of Example 78 can
optionally include wherein the downlink reference signal is
uncorrelated with the second received signal.
[0274] In Example 81, the subject matter of any one of Examples 78
to 80 can optionally include wherein the downlink reference signal
is a Primary Synchronization Signal (PSS), a Secondary
Synchronization Signal (SSS), or a Cell-specific Reference Signal
(CRS).
[0275] In Example 82, the subject matter of any one of Examples 68
to 81 can optionally include wherein reporting the signal power
measurement to the first wireless network as a measurement report
includes transmitting the measurement report to an access point of
the first wireless network.
[0276] In Example 83, the subject matter of any one of Examples 68
to 82 can optionally include wherein receiving a composite signal
including a first received signal from a first wireless network and
a second received signal from a second wireless network includes
receiving the composite signal during a downlink subframe of the
first wireless network or receiving the composite signal on a
downlink frequency band of the first wireless network.
[0277] In Example 84, the subject matter of any one of Examples 68
to 83 can optionally include wherein the composite signal further
includes noise, and wherein the signal power measurement is a
signal power measurement of the noise and the second received
signal.
[0278] In Example 85, the subject matter of any one of Examples 68
to 84 can optionally include wherein the first wireless network
utilizes a first radio frequency band that overlaps with a second
radio frequency band utilized by the second wireless network.
[0279] In Example 86, the subject matter of any one of Examples 68
to 85 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network.
[0280] In Example 87, the subject matter of any one of Examples 68
to 86 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network as
part of a spectrum sharing system.
[0281] In Example 88, the subject matter of any one of Examples 68
to 87 can optionally include wherein the first wireless network is
a licensee in a spectrum sharing system and the second wireless
network is an incumbent in the spectrum sharing system.
[0282] In Example 89, the subject matter of Example 88 can
optionally include wherein the spectrum sharing system is a
Licensed Shared Access (LSA) system or a Spectrum Access System
(SAS) system.
[0283] In Example 90, the subject matter of Example 88 or 89 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system.
[0284] In Example 91, the subject matter of any one of Examples 68
to 90 can optionally include wherein the first wireless network is
operated by a different network operator than the second wireless
network.
[0285] Example 92 is a mobile terminal including a radio processing
circuit and a baseband processing circuit configured to interact
with the radio processing circuit to transmit and receive radio
signals, the baseband processing circuit further configured to
perform the method of any one of Examples 68 to 91.
[0286] Example 93 is a non-transitory computer readable medium
storing instructions which when executed by a processor control the
processor to perform the method of any one of Examples 68 to
91.
[0287] Example 94 is a baseband processing circuit configured to
retrieve instructions from a memory which when executed by the
baseband processing circuit control the baseband processing circuit
to perform the method of any one of Examples 68 to 91.
[0288] Example 95 is a network control system for a first wireless
network including a network control circuit configured to manage
radio communications of the first wireless network, the network
control circuit further configured to estimate a proximity to a
second wireless network for a plurality of user terminals based on
a measurement of the second wireless network reported by the
plurality of user terminals, select one or more measurement
terminals from the plurality of user terminals based on the
estimated proximity of the plurality of user terminals, and receive
one or more interference measurements from the one or more
measurement terminals that indicate interference to the second
wireless network related to the first wireless network.
[0289] In Example 96, the subject matter of Example 95 can
optionally further include a radio transceiver configured to
transmit and receive radio signals on the first wireless
network.
[0290] In Example 97, the subject matter of Example 95 or 96 can
optionally include wherein the first wireless network and the
second wireless network operate on a shared frequency band.
[0291] In Example 98, the subject matter of any one of Examples 95
to 97 can optionally include wherein the network control circuit is
configured to select one or more measurement terminals from the
plurality of user terminals based on the estimated proximity of the
plurality of user terminals by selecting one or more of the
plurality of user terminals that report the strongest measurements
of the second wireless network as the one or more measurement
terminals.
[0292] In Example 99, the subject matter of any one of Examples 95
to 98 can optionally include wherein the network control circuit is
configured to estimate a proximity to a second wireless network for
a plurality of user terminals based on a measurement of the second
wireless network reported by the plurality of user terminals by
determining that one or more first user terminals of the plurality
of user terminals that report strong measurements are located
closer to the second wireless network than one or more second user
terminals of the plurality of user terminals that report weak
measurements.
[0293] In Example 100, the subject matter of any one of Examples 95
to 99 can optionally include wherein the network control circuit is
further configured to receive the measurement of the second
wireless network from each respective user terminal of the
plurality of user terminals.
[0294] In Example 101, the subject matter of Example 95 can
optionally include wherein the network control circuit is
configured to estimate a proximity to a second wireless network for
a plurality of user terminals based on a measurement of the second
wireless network reported by the plurality of user terminals by
estimating the proximity to the second wireless network for the
plurality of user terminals relative to the proximity of the other
user terminals of the plurality of user terminals to the second
wireless network based on the measurement of the second wireless
network reported by the plurality of user terminals.
[0295] In Example 102, the subject matter of Example 95 can
optionally include wherein the measurement of the second wireless
network reported by the plurality of user terminals is a signal
power measurement of the second wireless network, and wherein the
network control circuit is configured to estimate a proximity to a
second wireless network for a plurality of user terminals based on
a measurement of the second wireless network reported by the
plurality of user terminals by ranking the plurality of user
terminals in order according to the signal power measurement
reported by the plurality of user terminals.
[0296] In Example 103, the subject matter of Example 95 can
optionally include wherein the measurement of the second wireless
network reported by the plurality of user terminals is a signal
power measurement of the second wireless network, and wherein the
network control circuit is configured to estimate a proximity to a
second wireless network for a plurality of user terminals based on
a measurement of the second wireless network reported by the
plurality of user terminals by performing at least one of ranking
the plurality of user terminals according to the signal power
measurement reported by the plurality of user terminals, comparing
a signal power measurement reported by a first user terminal of the
plurality of user terminals to a signal power measurement reported
by a second user terminal of the plurality of user terminals,
comparing the signal power measurement reported by the plurality of
user terminals to a signal power threshold, or calculating an
approximate proximity from the second wireless network based on the
signal power measurement.
[0297] In Example 104, the subject matter of Example 95 can
optionally include wherein the network control circuit is further
configured to estimate a proximity to a transmission point of the
first wireless network of a further plurality of user terminals
based on a measurement of the transmission point reported by the
further plurality of user terminals, and select the plurality of
user terminals from the further plurality of user terminals based
on the estimated proximity of the further plurality of user
terminals from the transmission point.
[0298] In Example 105, the subject matter of Example 104 can
optionally include wherein the network control circuit is further
configured to select the user terminals of the further plurality of
user terminals that have the farthest estimated proximity from the
transmission point as the plurality of user terminals.
[0299] In Example 106, the subject matter of any one of Examples 95
to 105 can optionally include wherein the network control circuit
is further configured to determine whether to perform uplink power
control based on the one or more interference measurements.
[0300] In Example 107, the subject matter of Example 106 can
optionally include wherein the network control circuit is
configured to determine whether to perform uplink power control
based on the one or more interference measurements by determining
to perform uplink power control if the one or more interference
measurements indicate excessive interference to the second wireless
network.
[0301] In Example 108, the subject matter of Example 107 can
optionally include wherein the network control circuit is further
configured to select one or more target user terminals from the
plurality of user terminals to reduce allocated uplink transmit
power based on the estimated proximity of the one or more target
user terminals from the second wireless network.
[0302] In Example 109, the subject matter of Example 108 can
optionally include wherein the network control circuit is further
configured to transmit control signaling to the one or more target
terminals that specifies a reduction in uplink transmit power
allocation.
[0303] In Example 110, the subject matter of Example 106 can
optionally include wherein the network control circuit is
configured to determine whether to perform uplink power control
based on the one or more interference measurements by comparing the
one or more interference measurements to a predetermined
interference threshold, and determining to perform uplink power
control if the one or more interference measurements satisfy the
predetermined interference threshold.
[0304] In Example 111, the subject matter of Example 110 can
optionally include wherein the first wireless network is a licensee
in a spectrum sharing system and the second wireless network is an
incumbent in the spectrum sharing system, and wherein the
predetermined interference threshold is based on an incumbent
protection interference threshold of the spectrum sharing
system.
[0305] In Example 112, the subject matter of Example 111 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system and the incumbent
protection interference threshold is an interference threshold for
the protection zone.
[0306] In Example 113, the subject matter of Example 110 can
optionally include wherein the network control circuit is
configured to determine whether to perform uplink power control
based on the one or more interference measurements by determining
not to perform uplink power control if the one or more interference
measurements is below the predetermined interference threshold.
[0307] In Example 114, the subject matter of any one of Examples 95
to 113 can optionally include wherein the measurement of the second
wireless network reported by a first user terminal of the plurality
of user terminals is a signal power measurement that indicates a
signal power of a signal received by the first user terminal from
the second wireless network.
[0308] In Example 115, the subject matter of any one of Examples 95
to 114 can optionally include wherein the plurality of user
terminals utilize a first radio frequency band that overlaps with a
second radio frequency band utilized by the second wireless
network.
[0309] In Example 116, the subject matter of any one of Examples 95
to 115 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network.
[0310] In Example 117, the subject matter of any one of Examples 95
to 116 can optionally include wherein the first wireless network
utilizes a shared frequency with the second wireless network as
part of a spectrum sharing system.
[0311] In Example 118, the subject matter of any one of Examples 95
to 117 can optionally include wherein the first wireless network is
a licensee in a spectrum sharing system and the second wireless
network is an incumbent in the spectrum sharing system.
[0312] In Example 119, the subject matter of Example 118 can
optionally include wherein the spectrum sharing system is a
Licensed Shared Access (LSA) system or a Spectrum Access System
(SAS) system.
[0313] In Example 120, the subject matter of Example 118 or 119 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system.
[0314] In Example 121, the subject matter of any one of Examples 95
to 120 can optionally include wherein the control device is a base
station of the first wireless network.
[0315] In Example 122, the subject matter of any one of Examples 95
to 121 can optionally include wherein the control device is located
at a base station of the first wireless network.
[0316] In Example 123, the subject matter of any one of Examples 95
to 122 can optionally include wherein the first wireless network is
operated by a different network operator than the second wireless
network.
[0317] In Example 124, the subject matter of any one of Examples 95
to 123 can optionally include configured as a base station of the
first wireless network.
[0318] Example 125 is a network control system for a first wireless
network including a network control circuit configured to manage
radio communications of the first wireless network, the network
control circuit further configured to estimate a proximity to a
second wireless network for a plurality of user terminals based on
a measurement of the second wireless network reported by the
plurality of user terminals, determine whether the second wireless
network is experiencing excessive interference from the first
wireless network, and if the second wireless network is
experiencing excessive interference from the first wireless
network, adjust a transmit power allocation of one or more selected
user terminals of the plurality of user terminals based on the
estimated proximity to the second wireless network for the one or
more selected user terminals.
[0319] In Example 126, the subject matter of Example 125 can
optionally include wherein the first wireless network and the
second wireless network operate on a shared frequency band.
[0320] In Example 127, the subject matter of Example 125 or 126 can
optionally include wherein the network control circuit is further
configured to if the second wireless network is not experiencing
excessive interference from the first wireless network, perform one
of maintaining the transmit power allocation of the one or more
selected user terminals, or increasing the transmit power
allocation of one or more further user terminals of the plurality
of user terminals.
[0321] In Example 128, the subject matter of Example 127 can
optionally include wherein the network control circuit is
configured to increase the transmit power allocation of one or more
further user terminals of the plurality of user terminals by
selecting one or more user terminals of the plurality of user
terminals that have far estimated proximities to the second
wireless network as the one or more further user terminals.
[0322] In Example 129, the subject matter of Example 125 can
optionally include wherein the network control circuit is further
configured to select the one or more selected user terminals from
the plurality of user terminals based on which of the plurality of
user terminals have close estimated proximities to the second
wireless network.
[0323] In Example 130, the subject matter of Example 125 can
optionally include wherein the network control circuit is
configured to adjust a transmit power allocation of one or more
selected user terminals of the plurality of user terminals based on
the estimated proximity to the second wireless network for the one
or more selected user terminals by selecting one or more user
terminals of the plurality of user terminals that have close
estimated proximities to the second wireless network as the one or
more selected user terminals, and reducing the transmit power
allocation of the one or more selected user terminals.
[0324] In Example 131, the subject matter of Example 125 can
optionally include wherein the network control circuit is
configured to adjust a transmit power allocation of one or more
selected user terminals of the plurality of user terminals based on
the estimated proximity to the second wireless network for the one
or more selected user terminals by selecting one or more user
terminals of the plurality of user terminals that have close
estimated proximities to the second wireless network as the one or
more selected user terminals, and allocating zero uplink transmit
power for the one or more selected user terminals.
[0325] In Example 132, the subject matter of any one of Examples
125 to 131 can optionally include wherein the network control
circuit is further configured to receive one or more interference
measurements from one or more measurement terminals, and wherein
the network control circuit is configured to determine whether the
second wireless network is experiencing excessive interference from
the first wireless network by determining whether the second
wireless network is experiencing excessive interference from the
first wireless network based on the one or more interference
measurements.
[0326] In Example 133, the subject matter of Example 132 can
optionally include wherein the one or more measurement terminals
are user terminals of the plurality of user terminals.
[0327] In Example 134, the subject matter of Example 132 can
optionally include wherein the network control circuit is further
configured to select one or more measurement terminals from the
plurality of user terminals, and receive one or more one or more
interference measurements from one or more measurement terminals,
and wherein the network control circuit is configured to determine
whether the second wireless network is experiencing excessive
interference from the first wireless network by determining whether
the second wireless network is experiencing excessive interference
from the first wireless network based on the one or more
interference measurements.
[0328] In Example 135, the subject matter of Example 134 can
optionally include wherein the network control circuit is
configured to determine whether the second wireless network is
experiencing excessive interference from the first wireless network
based on the one or more interference measurements by determining
whether the one or more interference measurements satisfy
predetermined interference criteria.
[0329] In Example 136, the subject matter of Example 135 can
optionally include wherein the first wireless network is a licensee
in a spectrum sharing system and the second wireless network is an
incumbent in the spectrum sharing system, and wherein the
predetermined interference criteria is interference criteria of the
spectrum sharing system.
[0330] In Example 137, the subject matter of Example 135 can
optionally include wherein the first wireless network operates in a
protection zone of the spectrum sharing system, and wherein the
predetermined interference criteria is protection zone interference
criteria.
[0331] In Example 138, the subject matter of Example 134 can
optionally include wherein the network control circuit is
configured to determine whether the second wireless network is
experiencing excessive interference from the first wireless network
based on the one or more interference measurements by comparing the
one or more interference measurements to a predetermined
interference threshold.
[0332] In Example 139, the subject matter of Example 138 can
optionally include wherein the first wireless network is a licensee
in a spectrum sharing system and the second wireless network is an
incumbent in the spectrum sharing system, and wherein the
predetermined interference threshold is an interference threshold
of the spectrum sharing system.
[0333] In Example 140, the subject matter of Example 134 can
optionally include wherein the network control circuit is
configured to select one or more measurement terminals from the
plurality of user terminals by selecting the one or more
measurement terminals from the plurality of user terminals based on
the estimated proximity to the second wireless network for the one
or more measurement terminals.
[0334] In Example 141, the subject matter of Example 140 can
optionally include wherein the network control circuit is
configured to select the one or more measurement terminals from the
plurality of user terminals based on the estimated proximity to the
second wireless network for the one or more measurement terminals
by selecting one or more user terminals of the plurality of user
terminals that have the closest estimated proximities to the second
wireless network of the plurality of user terminals as the one or
more measurement terminals.
[0335] In Example 142, the subject matter of any one of Examples
125 to 141 can optionally include wherein the network control
circuit is configured to adjust a transmit power allocation of one
or more selected user terminals of the plurality of user terminals
based on the estimated proximity to the second wireless network for
the one or more selected user terminals by transmitting control
signaling to the one or more selected user terminals that specifies
an adjustment in transmit power allocation.
[0336] In Example 143, the subject matter of any one of Examples
125 to 142 can optionally include wherein the network control
circuit is configured to adjust a transmit power allocation of one
or more selected user terminals of the plurality of user terminals
based on the estimated proximity to the second wireless network for
the one or more selected user terminals by selecting one or more
user terminals of the plurality of user terminals that report the
strongest measurements of the second wireless network as the one or
more selected terminals, and reducing the transmit power allocation
of the one or more selected user terminals.
[0337] In Example 144, the subject matter of Example 125 can
optionally include wherein the network control circuit is
configured to estimate a proximity to a second wireless network for
a plurality of user terminals based on a measurement of the second
wireless network reported by the plurality of user terminals by
determining that one or more first user terminals of the plurality
of user terminals that report strong measurements of the second
wireless network are located closer to the second wireless network
than one or more second user terminals of the plurality of user
terminals that report weak measurements of the second wireless
network.
[0338] In Example 145, the subject matter of Example 125 can
optionally include wherein the network control circuit is
configured to estimate a proximity to a second wireless network for
a plurality of user terminals based on a measurement of the second
wireless network reported by the plurality of user terminals by
estimating the proximity to the second wireless network for the
plurality of user terminals relative to the proximity of the other
user terminals of the plurality of user terminals to the second
wireless network based on the measurement of the second wireless
network reported by the plurality of user terminals.
[0339] In Example 146, the subject matter of Example 125 can
optionally include wherein the measurement of the second wireless
network reported by the plurality of user terminals is a signal
power measurement of the second wireless network, and wherein the
network control circuit is configured to estimate a proximity to a
second wireless network for a plurality of user terminals based on
a measurement of the second wireless network reported by the
plurality of user terminals by ranking the plurality of user
terminals in order according to the signal power measurement
reported by the plurality of user terminals.
[0340] In Example 147, the subject matter of any one of Examples
125 to 146 can optionally include wherein the measurement of the
second wireless network reported by a first user terminal of the
plurality of user terminals is a signal power measurement that
indicates a signal power of a signal received by the first user
terminal from the second wireless network.
[0341] In Example 148, the subject matter of any one of Examples
125 to 147 can optionally include wherein the plurality of user
terminals utilize a first radio frequency band that overlaps with a
second radio frequency band utilized by the second wireless
network.
[0342] In Example 149, the subject matter of any one of Examples
125 to 148 can optionally include wherein the first wireless
network utilizes a shared frequency with the second wireless
network.
[0343] In Example 150, the subject matter of any one of Examples
125 to 149 can optionally include wherein the first wireless
network utilizes a shared frequency with the second wireless
network as part of a spectrum sharing system.
[0344] In Example 151, the subject matter of any one of Examples
125 to 150 can optionally include wherein the first wireless
network is a licensee in a spectrum sharing system and the second
wireless network is an incumbent in the spectrum sharing
system.
[0345] In Example 152, the subject matter of Example 151 can
optionally include wherein the spectrum sharing system is a
Licensed Shared Access (LSA) system or a Spectrum Access System
(SAS) system.
[0346] In Example 153, the subject matter of Example 151 or 152 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system.
[0347] In Example 154, the subject matter of any one of Examples
125 to 153 can optionally include wherein the first wireless
network is operated by a different network operator than the second
wireless network.
[0348] In Example 155, the subject matter of any one of Examples
125 to 154 can optionally include configured as a base station of
the first wireless network.
[0349] Example 156 is a mobile terminal including a radio
processing circuit and a baseband processing circuit configured to
interact with the radio processing circuit to transmit and receive
radio signals, the baseband processing circuit further configured
to receive a composite signal including a first received signal
from a first wireless network and a second received signal from a
second wireless network, calculate a correlation between the
composite signal and a local reference signal to determine a signal
power measurement of the second received signal, report the signal
power measurement to the first wireless network as a measurement
report, and receive control signaling in response to the
measurement report that specifies an assigned operation
configuration for the user terminal.
[0350] In Example 157, the subject matter of Example 156 can
optionally include wherein the first wireless network and the
second wireless network operate on a shared frequency band.
[0351] In Example 158, the subject matter of Example 156 or 157 can
optionally include wherein the baseband processing circuit is
configured to receive control signaling in response to the
measurement report that specifies an operation assignment for the
user terminal by receiving a measurement operation assignment, the
baseband processing circuit further configured to perform an
interference measurement that indicates interference to the second
wireless network, and report the interference measurement to the
first wireless network.
[0352] In Example 159, the subject matter of Example 158 can
optionally include wherein the interference measurement indicates
interference to the second wireless network related to the first
wireless network.
[0353] In Example 160, the subject matter of Example 158 can
optionally include wherein the baseband processing circuit is
configured to perform an interference measurement that indicates
interference to the second wireless network by subtracting a
downlink reference signal power measurement from an uplink signal
power measurement to obtain a signal power measurement difference,
and subtracting an estimated reference signal power measurement
from the signal power measurement difference to obtain the
interference measurement.
[0354] In Example 161, the subject matter of any one of Examples
156 to 160 can optionally include wherein the baseband processing
circuit is configured to receive control signaling in response to
the measurement report that specifies an operation assignment for
the user terminal by receiving a transmit power operation
assignment that specifies a transmit power, the baseband processing
circuit further configured to transmit signals according to the
transmit power.
[0355] In Example 162, the subject matter of any one of Examples
156 to 161 can optionally include wherein the baseband processing
circuit is configured to calculate a correlation between the
composite signal and a local reference signal to determine a signal
power measurement of the second received signal by calculating a
cross-correlation between the composite signal and the local
reference signal to obtain the signal power measurement of the
second received signal.
[0356] In Example 163, the subject matter of any one of Examples
156 to 161 can optionally include wherein the baseband processing
circuit is configured to calculate a correlation between the
composite signal and a local reference signal to determine a signal
power measurement of the second received signal by calculating a
cross-correlation between the composite signal and the local
reference signal to obtain a reference signal channel response,
calculating a reference signal power measurement from the reference
signal channel response, and subtracting the reference signal power
measurement from a signal power measurement of the composite signal
to obtain the signal power measurement of the second received
signal.
[0357] In Example 164, the subject matter of Example 163 can
optionally include wherein the baseband processing circuit is
configured to calculate a cross-correlation between the composite
signal and the local reference signal to obtain a reference signal
channel response by calculating the cross-correlation between the
composite signal and the local reference signal in the frequency
domain to obtain the reference signal channel response as a
reference signal channel frequency response.
[0358] In Example 165, the subject matter of Example 164 can
optionally include wherein the baseband processing circuit is
configured to calculate a reference signal power measurement from
the reference signal channel response by calculating the reference
signal power measurement from the reference signal channel
frequency response.
[0359] In Example 166, the subject matter of any one of Examples
156 to 165 can optionally include wherein the first received signal
includes a downlink reference signal transmitted by a transmission
point of the first wireless network.
[0360] In Example 167, the subject matter of Example 166 can
optionally include wherein the baseband processing circuit is
configured to receive a composite signal including a first received
signal from a first wireless network and a second received signal
from a second wireless network by receiving the composite signal
during a downlink reference signal occasion of the first wireless
network.
[0361] In Example 168, the subject matter of Example 166 can
optionally include wherein the downlink reference signal is
uncorrelated with the second received signal.
[0362] In Example 169, the subject matter of any one of Examples
166 to 168 can optionally include wherein the downlink reference
signal is a Primary Synchronization Signal (PSS), a Secondary
Synchronization Signal (SSS), or a Cell-specific Reference Signal
(CRS).
[0363] In Example 170, the subject matter of Example one can
optionally include Examples 156 to 169, wherein the baseband
processing circuit is configured to report the signal power
measurement to the first wireless network as a measurement report
by transmitting the measurement report to an access point of the
first wireless network.
[0364] In Example 171, the subject matter of any one of Examples
156 to 170 can optionally include wherein the baseband processing
circuit is configured to receive a composite signal including a
first received signal from a first wireless network and a second
received signal from a second wireless network by receiving the
composite signal during a downlink subframe of the first wireless
network or receiving the composite signal on a downlink frequency
band of the first wireless network.
[0365] In Example 172, the subject matter of any one of Examples
156 to 171 can optionally include wherein the composite signal
further includes noise, and wherein the signal power measurement is
a signal power measurement of the noise and the second received
signal.
[0366] In Example 173, the subject matter of any one of Examples
156 to 172 can optionally include wherein the first wireless
network utilizes a first radio frequency band that overlaps with a
second radio frequency band utilized by the second wireless
network.
[0367] In Example 174, the subject matter of any one of Examples
156 to 173 can optionally include wherein the first wireless
network utilizes a shared frequency with the second wireless
network.
[0368] In Example 175, the subject matter of any one of Examples
156 to 174 can optionally include wherein the first wireless
network utilizes a shared frequency with the second wireless
network as part of a spectrum sharing system.
[0369] In Example 176, the subject matter of any one of Examples
156 to 175 can optionally include wherein the first wireless
network is a licensee in a spectrum sharing system and the second
wireless network is an incumbent in the spectrum sharing
system.
[0370] In Example 177, the subject matter of Example 176 can
optionally include wherein the spectrum sharing system is a
Licensed Shared Access (LSA) system or a Spectrum Access System
(SAS) system.
[0371] In Example 178, the subject matter of Example 176 or 177 can
optionally include wherein the first wireless network is located in
a protection zone of the spectrum sharing system.
[0372] In Example 179, the subject matter of any one of Examples
156 to 178 can optionally include wherein the first wireless
network is operated by a different network operator than the second
wireless network.
[0373] While the invention has been particularly shown and
described with reference to specific embodiments, it should be
understood by those skilled in the art that various changes in form
and detail may be made therein without departing from the spirit
and scope of the invention as defined by the appended claims. The
scope of the invention is thus indicated by the appended claims and
all changes which come within the meaning and range of equivalency
of the claims are therefore intended to be embraced.
* * * * *