U.S. patent application number 15/289043 was filed with the patent office on 2017-11-30 for high frequency wireless communication system paging.
The applicant listed for this patent is QUALCOMM Incorporated. Invention is credited to Sony Akkarakaran, Tao Luo, Sumeeth Nagaraja.
Application Number | 20170347334 15/289043 |
Document ID | / |
Family ID | 60407800 |
Filed Date | 2017-11-30 |
United States Patent
Application |
20170347334 |
Kind Code |
A1 |
Akkarakaran; Sony ; et
al. |
November 30, 2017 |
HIGH FREQUENCY WIRELESS COMMUNICATION SYSTEM PAGING
Abstract
Systems and methods of wireless communication of a paging signal
are disclosed. According to some aspects of the disclosure, a
sequence of a plurality of beam configurations may be selected for
use in communicating a paging signal between a pair of wireless
devices. Beam configurations can include beam configurations of
different angular widths. Beam configurations may be iteratively
used to attempt to successfully communicate the paging signal
between the pair of wireless devices. Each iteration may use a beam
configuration of a different angular width and/or a plurality of
facing angles. Other aspects, embodiments, and features are also
claimed and described.
Inventors: |
Akkarakaran; Sony; (Poway,
CA) ; Luo; Tao; (San Diego, CA) ; Nagaraja;
Sumeeth; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Family ID: |
60407800 |
Appl. No.: |
15/289043 |
Filed: |
October 7, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62342656 |
May 27, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 25/0202 20130101;
H04W 68/06 20130101; H04W 16/28 20130101; H04W 68/04 20130101; H04B
7/0617 20130101; H04W 68/02 20130101; H04W 68/08 20130101 |
International
Class: |
H04W 68/02 20090101
H04W068/02; H04W 68/04 20090101 H04W068/04; H04L 25/02 20060101
H04L025/02; H04W 68/06 20090101 H04W068/06; H04B 7/06 20060101
H04B007/06 |
Claims
1. A method of wireless communication of a paging signal,
comprising: selecting a sequence of a plurality of beam
configurations of different angular widths for use in communicating
the paging signal between a pair of wireless devices; and
iteratively using beam configurations of the plurality of beam
configurations having different angular widths to attempt
communication of the paging signal between the pair of wireless
devices, wherein each iteration uses a beam having a respective one
of the different angular widths at a plurality of facing
angles.
2. The method of claim 1, wherein the iteratively using beam
configurations of the plurality of beam configurations is continued
until either each iteration for each beam configuration has used
its respective different angular width beam configuration at each
facing angle of the plurality of facing angles for that angular
width beam configuration or the paging signal has successfully been
communicated between the pair of wireless devices.
3. The method of claim 1, further comprising: initially selecting a
broad beam configuration of the plurality of beam configurations
and using the broad beam configuration at each facing angle of the
plurality of facing angles to transmit the paging signal; and
subsequently selecting a more narrow beam configuration of the
plurality of beam configurations and using the more narrow beam
configuration at each facing angle of the plurality of facing
angles to transmit the paging signal.
4. The method of claim 1, further comprising: monitoring, by a
first wireless device of the pair of wireless devices, for a
ready-to-be-paged indication from a second wireless device of the
pair of wireless devices; and refining the sequence of a plurality
of beam configurations for use in communicating the paging signal
based at least in part on the ready-to-be-paged indication.
5. The method of claim 4, wherein the ready-to-be-paged indication
is transmitted in response to the second wireless device
determining that broadcast paging has failed.
6. The method of claim 4, wherein the ready-to-be-paged indication
is transmitted by the second wireless device based at least in part
on downlink channel estimation by the second wireless device.
7. The method of claim 6, wherein the ready-to-be-paged indication
is transmitted by the second wireless device only if the downlink
channel estimation is below a threshold.
8. The method of claim 1, further comprising: selecting a first
configuration of the plurality of beam configurations and using the
first configuration at each facing angle of the plurality of facing
angles to transmit the paging signal encoded at a first code rate;
monitoring, by a first wireless device of the pair of wireless
devices, for a page response from a second wireless device of the
pair of wireless devices; and if no page response is received from
the second wireless device, selecting at least one of a second beam
configuration of the plurality of beam configurations for using the
second beam configuration to transmit the paging signal or a second
code rate to encode the paging signal for transmitting.
9. The method of claim 8, wherein the second beam configuration is
a beam configuration having a wider beam angle that the first beam
configuration and the second code rate is a code rate having a
lower code rate than the first code rate.
10. The method of claim 1, further comprising: collecting paging
messages for multiple wireless devices that are determined to use
similar beam configurations for paging signal transmission, wherein
the iteratively using beam configurations of the plurality of beam
configurations comprises selecting a configuration of the plurality
of beam configurations corresponding to the similar beam
configurations and using the selected configuration at each facing
angle of the plurality of facing angles for paging signal
transmission to the multiple wireless devices.
11. The method of claim 1, further comprising: selecting a sequence
of a plurality of beam configurations having a spatially broadest
beam configuration that will cover a determined distance between
the pair of wireless devices or that will cover a worst case
distance for the pair of wireless devices when a distance between
the pair of wireless devices is unknown.
12. The method of claim 1, further comprising: estimating a prior
probability distribution of a location of a wireless device of the
wireless device pair; and selecting a sequence of a plurality of
beam configurations to probabilistically result in the wireless
device receiving the paging signal based on the estimated prior
probability distribution.
13. A non-transitory computer-readable medium having program code
recorded thereon, the program code comprising: program code for
causing a computer to: select a sequence of a plurality of beam
configurations of different angular widths for use in communicating
the paging signal between a pair of wireless devices; and
iteratively use beam configurations of the plurality of beam
configurations having different angular widths to attempt
communication of the paging signal between the pair of wireless
devices, wherein each iteration uses a beam having a respective one
of the different angular widths at a plurality of facing
angles.
14. The non-transitory computer-readable medium of claim 13,
wherein the iteratively use of beam configurations of the plurality
of beam configurations is continued until either each iteration for
each beam configuration has used its respective different angular
width beam configuration at each facing angle of the plurality of
facing angles for that angular beam width configuration or the
paging signal has successfully been communicated between the pair
of wireless devices.
15. The non-transitory computer-readable medium of claim 13,
wherein the program code further causes the computer to: monitor,
by a first wireless device of the pair of wireless devices, for a
ready-to-be-paged indication from a second wireless device of the
pair of wireless devices; and refine the sequence of a plurality of
beam configurations for use in communicating the paging signal
based at least in part on the ready-to-be-paged indication.
16. The non-transitory computer-readable medium of claim 13,
wherein the program code further causes the computer to: select a
first configuration of the plurality of beam configurations and
using the first configuration at each facing angle of the plurality
of facing angles to transmit the paging signal encoded at a first
code rate; monitor, by a first wireless device of the pair of
wireless devices, for a page response from a second wireless device
of the pair of wireless devices; and select at least one of a
second beam configuration of the plurality of beam configurations
for using the second beam configuration to transmit the paging
signal or a second code rate to encode the paging signal for
transmitting if no page response is received from the second
wireless device.
17. The non-transitory computer-readable medium of claim 13,
wherein the program code further causes the computer to: select a
sequence of a plurality of beam configurations having a spatially
broadest beam configuration that will cover a determined distance
between the pair of wireless devices or that will cover a worst
case distance for the pair of wireless devices when a distance
between the pair of wireless devices is unknown.
18. The non-transitory computer-readable medium of claim 13,
wherein the program code further causes the computer to: estimate a
prior probability distribution of a location of a wireless device
of the wireless device pair; and select a sequence of a plurality
of beam configurations to probabilistically result in the wireless
device receiving the paging signal based on the estimated prior
probability distribution.
19. An apparatus configured for wireless communication of a paging
signal, the apparatus comprising: at least one processor; and a
memory coupled to the at least one processor, wherein the at least
one processor is configured: to select a sequence of a plurality of
beam configurations of different angular widths for use in
communicating the paging signal between a pair of wireless devices;
and to iteratively use beam configurations of the plurality of beam
configurations having different angular widths to attempt
communication of the paging signal between the pair of wireless
devices, wherein each iteration uses a beam having a respective one
of the different angular widths at a plurality of facing
angles.
20. The apparatus of claim 19, wherein the iteratively using beam
configurations of the plurality of beam configurations is continued
until either each iteration for each beam configuration has used
its respective different angular width beam configuration at each
facing angle of the plurality of facing angles for that angular
beam configuration or the paging signal has successfully been
communicated between the pair of wireless devices.
21. The apparatus of claim 19, wherein the at least one processor
is further configured: to initially select a broad beam
configuration of the plurality of beam configurations and use the
broad beam configuration at each facing angle of the plurality of
facing angles to transmit the paging signal; and to subsequently
select a more narrow beam configuration of the plurality of beam
configurations and use the more narrow beam configuration at each
facing angle of the plurality of facing angles to transmit the
paging signal.
22. The apparatus of claim 19, wherein the at least one processor
is further configured: to monitor, by a first wireless device of
the pair of wireless devices, for a ready-to-be-paged indication
from a second wireless device of the pair of wireless devices; and
to refine the sequence of a plurality of beam configurations for
use in communicating the paging signal based at least in part on
the ready-to-be-paged indication.
23. The apparatus of claim 22, wherein the ready-to-be-paged
indication is transmitted in response to the second wireless device
determining that broadcast paging has failed.
24. The apparatus of claim 22, wherein the ready-to-be-paged
indication is transmitted by the second wireless device based at
least in part on downlink channel estimation by the second wireless
device.
25. The apparatus of claim 24, wherein the ready-to-be-paged
indication is transmitted by the second wireless device only if the
downlink channel estimation is below a threshold.
26. The apparatus of claim 19, wherein the at least one processor
is further configured: to select a first configuration of the
plurality of beam configurations and using the first configuration
at each facing angle of the plurality of facing angles to transmit
the paging signal encoded at a first code rate; to monitor, by a
first wireless device of the pair of wireless devices, for a page
response from a second wireless device of the pair of wireless
devices; and to select at least one of a second beam configuration
of the plurality of beam configurations for using the second beam
configuration to transmit the paging signal or a second code rate
to encode the paging signal for transmitting if no page response is
received from the second wireless device.
27. The apparatus of claim 26, wherein the second beam
configuration is a beam configuration having a wider beam angle
that the first beam configuration and the second code rate is a
code rate having a lower code rate than the first code rate.
28. The apparatus of claim 19, wherein the at least one processor
is further configured: collect paging messages for multiple
wireless devices that are determined to use similar beam
configurations for paging signal transmission, wherein the
iteratively use of beam configurations of the plurality of beam
configurations selects a configuration of the plurality of beam
configurations corresponding to the similar beam configurations and
using the selected configuration at each facing angle of the
plurality of facing angles for paging signal transmission to the
multiple wireless devices.
29. The apparatus of claim 19, wherein the at least one processor
is further configured: to select a sequence of a plurality of beam
configurations having a spatially broadest beam configuration that
will cover a determined distance between the pair of wireless
devices or that will cover a worst case distance for the pair of
wireless devices when a distance between the pair of wireless
devise is unknown.
30. The apparatus of claim 19, wherein the at least one processor
is further configured: to estimate a prior probability distribution
of a location of a wireless device of the wireless device pair; and
to select a sequence of a plurality of beam configurations to
probabilistically result in the wireless device receiving the
paging signal based on the estimated prior probability
distribution.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 62/342,656, entitled, "HIGH FREQUENCY
WIRELESS COMMUNICATION SYSTEM PAGING", filed on May 27, 2016, which
is expressly incorporated by reference herein in its entirety as is
fully set forth below and for all applicable purposes.
TECHNICAL FIELD
[0002] Aspects of the present disclosure relate generally to
wireless communication systems, and more particularly, to paging in
wireless communication systems using high frequency carriers, such
as millimeter-wave carriers.
Introduction
[0003] Wireless communication networks are widely deployed to
provide various communication services such as voice, video, packet
data, messaging, broadcast, and the like. These wireless networks
may be multiple-access networks capable of supporting multiple
users by sharing the available network resources. Such networks,
which are usually multiple access networks, support communications
for multiple users by sharing the available network resources.
[0004] A wireless communication network may include a number of
base stations or node Bs that can support communication for a
number of user equipments (UEs). A UE may communicate with a base
station via downlink and uplink. The downlink (or forward link)
refers to the communication link from the base station to the UE,
and the uplink (or reverse link) refers to the communication link
from the UE to the base station.
[0005] A base station may transmit data and control information on
the downlink to a UE and/or may receive data and control
information on the uplink from the UE. On the downlink, a
transmission from the base station may encounter interference due
to transmissions from neighbor base stations or from other wireless
radio frequency (RF) transmitters. On the uplink, a transmission
from the UE may encounter interference from uplink transmissions of
other UEs communicating with the neighbor base stations or from
other wireless RF transmitters. This interference may degrade
performance on both the downlink and uplink.
[0006] As the demand for mobile broadband access continues to
increase, the possibilities of interference and congested networks
grows with more UEs accessing the long-range wireless communication
networks and more short-range wireless systems being deployed in
communities. Research and development continue to advance the
wireless communication technologies not only to meet the growing
demand for mobile broadband access, but to advance and enhance the
user experience with mobile communications.
BRIEF SUMMARY OF SOME EXAMPLE EMBODIMENTS
[0007] The following summarizes some aspects of the present
disclosure to provide a basic understanding of the discussed
technology. This summary is not an extensive overview of all
contemplated features of the disclosure, and is intended neither to
identify key or critical elements of all aspects of the disclosure
nor to delineate the scope of any or all aspects of the disclosure.
Its sole purpose is to present some concepts of one or more aspects
of the disclosure in summary form as a prelude to the more detailed
description that is presented later.
[0008] In one aspect of the disclosure, a method of wireless
communication of a paging signal is provided. The method includes
selecting a sequence of a plurality of beam configurations of
different angular widths for use in communicating the paging signal
between a pair of wireless devices. The method further includes
iteratively using beam configurations of the plurality of beam
configurations having different angular widths to attempt
communication of the paging signal between the pair of wireless
devices. Each iteration may use a beam having a respective one of
the different angular widths at a plurality of facing angles.
[0009] In an additional aspect of the disclosure, an apparatus
configured for wireless communication of a paging signal is
provided. The apparatus includes means for selecting a sequence of
a plurality of beam configurations of different angular widths for
use in communicating the paging signal between a pair of wireless
devices. The apparatus further includes means for iteratively using
beam configurations of the plurality of beam configurations having
different angular widths to attempt communication of the paging
signal between the pair of wireless devices. Each iteration may use
a beam having a respective one of the different angular widths at a
plurality of facing angles.
[0010] In an additional aspect of the disclosure, a non-transitory
computer-readable medium having program code recorded thereon. The
program code includes code to select a sequence of a plurality of
beam configurations of different angular widths for use in
communicating the paging signal between a pair of wireless devices.
The code further includes code to iteratively use beam
configurations of the plurality of beam configurations having
different angular widths to attempt communication of the paging
signal between the pair of wireless devices. Each iteration may use
a beam having a respective one of the different angular widths at a
plurality of facing angles.
[0011] In an additional aspect of the disclosure, an apparatus
configured for wireless communication of a paging signal is
disclosed. The apparatus includes at least one processor, and a
memory coupled to the processor. The processor is configured to
select a sequence of a plurality of beam configurations of
different angular widths for use in communicating the paging signal
between a pair of wireless devices. The processor is further
configured to iteratively use beam configurations of the plurality
of beam configurations having different angular widths to attempt
communication of the paging signal between the pair of wireless
devices. Each iteration may use a beam having a respective one of
the different angular widths at a plurality of facing angles.
[0012] Other aspects, features, and embodiments of the present
invention will become apparent to those of ordinary skill in the
art, upon reviewing the following description of specific,
exemplary embodiments of the present invention in conjunction with
the accompanying figures. While features of the present invention
may be discussed relative to certain embodiments and figures below,
all embodiments of the present invention can include one or more of
the advantageous features discussed herein. In other words, while
one or more embodiments may be discussed as having certain
advantageous features, one or more of such features may also be
used in accordance with the various embodiments of the invention
discussed herein. In similar fashion, while exemplary embodiments
may be discussed below as device, system, or method embodiments it
should be understood that such exemplary embodiments can be
implemented in various devices, systems, and methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A further understanding of the nature and advantages of the
present disclosure may be realized by reference to the following
drawings. In the appended figures, similar components or features
may have the same reference label. Further, various components of
the same type may be distinguished by following the reference label
by a dash and a second label that distinguishes among the similar
components. If just the first reference label is used in the
specification, the description is applicable to any one of the
similar components having the same first reference label
irrespective of the second reference label.
[0014] FIG. 1 is a block diagram illustrating details of a wireless
communication system according to some embodiments of the present
disclosure.
[0015] FIG. 2 is a block diagram conceptually illustrating a design
of a base station/eNB and a UE configured according to some
embodiments of the present disclosure.
[0016] FIG. 3 is a block diagram illustrating details of a wireless
communication system adapted according to some embodiments of the
present disclosure.
[0017] FIG. 4 is a flow diagram showing operation in accordance
with some embodiments of the present disclosure.
DETAILED DESCRIPTION
[0018] The detailed description set forth below, in connection with
the appended drawings, is intended as a description of various
possible configurations and is not intended to limit the scope of
the disclosure. Rather, the detailed description includes specific
details for the purpose of providing a thorough understanding of
the inventive subject matter. It will be apparent to those skilled
in the art that these specific details are not required in every
case and that, in some instances, well-known structures and
components are shown in block diagram form for clarity of
presentation.
[0019] This disclosure relates generally to providing or
participating in authorized shared access between two or more
wireless communications systems, also referred to as wireless
communications networks. In various embodiments, the techniques and
apparatus may be used for wireless communication networks such as
code division multiple access (CDMA) networks, time division
multiple access (TDMA) networks, frequency division multiple access
(FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier
FDMA (SC-FDMA) networks, LTE networks, GSM networks, as well as
other communications networks. As described herein, the terms
"networks" and "systems" may be used interchangeably.
[0020] A CDMA network may implement a radio technology such as
universal terrestrial radio access (UTRA), cdma2000, and the like.
UTRA includes wideband-CDMA (W-CDMA) and low chip rate (LCR).
CDMA2000 covers IS-2000, IS-95, and IS-856 standards.
[0021] A TDMA network may implement a radio technology such as
Global System for Mobile Communications (GSM). 3GPP defines
standards for the GSM EDGE (enhanced data rates for GSM evolution)
radio access network (RAN), also denoted as GERAN. GERAN is the
radio component of GSM/EDGE, together with the network that joins
the base stations (for example, the Ater and Abis interfaces) and
the base station controllers (A interfaces, etc.). The radio access
network represents a component of a GSM network, through which
phone calls and packet data are routed from and to the public
switched telephone network (PSTN) and Internet to and from
subscriber handsets, also known as user terminals or user
equipments (UEs). A mobile phone operator's network may comprise
one or more GERANs, which may be coupled with UTRANs in the case of
a UMTS/GSM network. An operator network may also include one or
more LTE networks, and/or one or more other networks. The various
different network types may use different radio access technologies
(RATs) and radio access networks (RANs).
[0022] An OFDMA network may implement a radio technology such as
evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20,
flash-OFDM and the like. UTRA, E-UTRA, and GSM are part of
universal mobile telecommunication system (UMTS). In particular,
long term evolution (LTE) is a release of UMTS that uses E-UTRA.
UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided
from an organization named "3rd Generation Partnership Project"
(3GPP), and cdma2000 is described in documents from an organization
named "3rd Generation Partnership Project 2" (3GPP2). These various
radio technologies and standards are known or are being developed.
For example, the 3rd Generation Partnership Project (3GPP) is a
collaboration between groups of telecommunications associations
that aims to define a globally applicable third generation (3G)
mobile phone specification. 3GPP long term evolution (LTE) is a
3GPP project aimed at improving the universal mobile
telecommunications system (UMTS) mobile phone standard. The 3GPP
may define specifications for the next generation of mobile
networks, mobile systems, and mobile devices. For clarity, certain
aspects of the apparatus and techniques may be described below for
LTE implementations or in an LTE-centric way, and LTE terminology
may be used as illustrative examples in portions of the description
below; however, the description is not intended to be limited to
LTE applications. Indeed, the present disclosure is concerned with
shared access to wireless spectrum between networks using different
radio access technologies or radio air interfaces.
[0023] A new carrier type based on LTE/LTE-A including unlicensed
spectrum has also been suggested that can be compatible with
carrier-grade WiFi, making LTE/LTE-A with unlicensed spectrum an
alternative to WiFi. LTE/LTE-A, when operating in unlicensed
spectrum, may leverage LTE concepts and may introduce some
modifications to physical layer (PHY) and media access control
(MAC) aspects of the network or network devices to provide
efficient operation in the unlicensed spectrum and meet regulatory
requirements. The unlicensed spectrum used may range from as low as
several hundred Megahertz (MHz) to as high as tens of Gigahertz
(GHz), for example. In operation, such LTE/LTE-A networks may
operate with any combination of licensed or unlicensed spectrum
depending on loading and availability. Accordingly, it may be
apparent to one of skill in the art that the systems, apparatus and
methods described herein may be applied to other communications
systems and applications.
[0024] System designs may support various time-frequency reference
signals for the downlink and uplink to facilitate beamforming and
other functions. A reference signal is a signal generated based on
known data and may also be referred to as a pilot, preamble,
training signal, sounding signal, and the like. A reference signal
may be used by a receiver for various purposes such as channel
estimation, coherent demodulation, channel quality measurement,
signal strength measurement, and the like. MIMO systems using
multiple antennas generally provide for coordination of sending of
reference signals between antennas; however, LTE systems do not in
general provide for coordination of sending of reference signals
from multiple base stations or eNBs.
[0025] In some implementations, a system may utilize time division
duplexing (TDD). For TDD, the downlink and uplink share the same
frequency spectrum or channel, and downlink and uplink
transmissions are sent on the same frequency spectrum. The downlink
channel response may thus be correlated with the uplink channel
response. Reciprocity may allow a downlink channel to be estimated
based on transmissions sent via the uplink. These uplink
transmissions may be reference signals or uplink control channels
(which may be used as reference symbols after demodulation). The
uplink transmissions may allow for estimation of a space-selective
channel via multiple antennas.
[0026] In LTE implementations, orthogonal frequency division
multiplexing (OFDM) is used for the downlink--that is, from a base
station, access point or eNodeB (eNB) to a user terminal or UE. Use
of OFDM meets the LTE requirement for spectrum flexibility and
enables cost-efficient solutions for very wide carriers with high
peak rates, and is a well-established technology. For example, OFDM
is used in standards such as IEEE 802.11a/g, 802.16, High
Performance Radio LAN-2 (HIPERLAN-2, wherein LAN stands for Local
Area Network) standardized by the European Telecommunications
Standards Institute (ETSI), Digital Video Broadcasting (DVB)
published by the Joint Technical Committee of ETSI, and other
standards.
[0027] Time frequency physical resource blocks (also denoted here
in as resource blocks or "RBs" for brevity) may be defined in OFDM
systems as groups of transport carriers (e.g. sub-carriers) or
intervals that are assigned to transport data. The RBs are defined
over a time and frequency period. Resource blocks are comprised of
time-frequency resource elements (also denoted here in as resource
elements or "REs" for brevity), which may be defined by indices of
time and frequency in a slot. Additional details of LTE RBs and REs
are described in the 3GPP specifications, such as, for example,
3GPP TS 36.211.
[0028] UMTS LTE supports scalable carrier bandwidths from 20 MHz
down to 1.4 MHZ. In LTE, an RB is defined as 12 sub-carriers when
the subcarrier bandwidth is 15 kHz, or 24 sub-carriers when the
sub-carrier bandwidth is 7.5 kHz. In an exemplary implementation,
in the time domain there is a defined radio frame that is 10 ms
long and consists of 10 subframes of 1 millisecond (ms) each. Every
subframe consists of 2 slots, where each slot is 0.5 ms. The
subcarrier spacing in the frequency domain in this case is 15 kHz.
Twelve of these subcarriers together (per slot) constitute an RB,
so in this implementation one resource block is 180 kHz. Six
Resource blocks fit in a carrier of 1.4 MHz and 100 resource blocks
fit in a carrier of 20 MHz.
[0029] FIG. 1 shows a wireless network 100 for communication
according to some embodiments. While discussion of the technology
of this disclosure is provided relative to an LTE-A network (shown
in FIG. 1), this is for illustrative purposes. Principles of the
technology disclosed can be used in other network deployments,
including fifth generation networks. As appreciated by those
skilled in the art, components appearing in FIG. 1 are likely to
have related counterparts in other network arrangements.
[0030] Turning back to FIG. 1, the wireless network 100 includes a
number of evolved node Bs (eNBs) 105 and other network entities. An
eNB may be a station that communicates with the UEs and may also be
referred to as a base station, a node B, an access point, and the
like. Each eNB 105 may provide communication coverage for a
particular geographic area. In 3GPP, the term "cell" can refer to
this particular geographic coverage area of an eNB and/or an eNB
subsystem serving the coverage area, depending on the context in
which the term is used.
[0031] An eNB may provide communication coverage for a macro cell
or a small cell, such as a pico cell or a femto cell, and/or other
types of cell. A macro cell generally covers a relatively large
geographic area (e.g., several kilometers in radius) and may allow
unrestricted access by UEs with service subscriptions with the
network provider. A small cell, such as a pico cell, would
generally cover a relatively smaller geographic area and may allow
unrestricted access by UEs with service subscriptions with the
network provider. A small cell, such as a femto cell, would also
generally cover a relatively small geographic area (e.g., a home)
and, in addition to unrestricted access, may also provide
restricted access by UEs having an association with the femto cell
(e.g., UEs in a closed subscriber group (CSG), UEs for users in the
home, and the like). An eNB for a macro cell may be referred to as
a macro eNB. An eNB for a small cell may be referred to as a small
cell eNB, a pico eNB, a femto eNB or a home eNB. In the example
shown in FIG. 1, the eNBs 105a, 105b and 105c are macro eNBs for
the macro cells 110a, 110b and 110c, respectively. The eNBs 105x,
105y, and 105z are small cell eNBs, which may include pico or femto
eNBs that provide service to small cells 110x, 110y, and 110z,
respectively. An eNB may support one or multiple (e.g., two, three,
four, and the like) cells.
[0032] The wireless network 100 may support synchronous or
asynchronous operation. For synchronous operation, the eNBs may
have similar frame timing, and transmissions from different eNBs
may be approximately aligned in time. For asynchronous operation,
the eNBs may have different frame timing, and transmissions from
different eNBs may not be aligned in time.
[0033] The UEs 115 are dispersed throughout the wireless network
100, and each UE may be stationary or mobile. It should be
appreciated that, although a mobile apparatus is commonly referred
to as user equipment (UE) in standards and specifications
promulgated by the 3rd Generation Partnership Project (3GPP), such
apparatus may also be referred to by those skilled in the art as a
mobile station (MS), a subscriber station, a mobile unit, a
subscriber unit, a wireless unit, a remote unit, a mobile device, a
wireless device, a wireless communications device, a remote device,
a mobile subscriber station, an access terminal (AT), a mobile
terminal, a wireless terminal, a remote terminal, a handset, a
terminal, a user agent, a mobile client, a client, or some other
suitable terminology. Within the present document, a "mobile"
apparatus or UE need not necessarily have a capability to move, and
may be stationary. Some non-limiting examples of a mobile
apparatus, such as may comprise embodiments of one or more of the
UEs 115, include a mobile, a cellular (cell) phone, a smart phone,
a session initiation protocol (SIP) phone, a laptop, a personal
computer (PC), a notebook, a netbook, a smart book, a tablet, and a
personal digital assistant (PDA). A mobile apparatus may
additionally be an "Internet of things" (IoT) device such as an
automotive or other transportation vehicle, a satellite radio, a
global positioning system (GPS) device, a logistics controller, a
drone, a multi-copter, a quad-copter, a smart energy or security
device, a solar panel or solar array, municipal lighting, water, or
other infrastructure; industrial automation and enterprise devices;
consumer and wearable devices, such as eyewear, a wearable camera,
a smart watch, a health or fitness tracker, a mammal implantable
device, medical device, a digital audio player (e.g., MP3 player),
a camera, a game console, etc.; and digital home or smart home
devices such as a home audio, video, and multimedia device, an
appliance, a sensor, a vending machine, intelligent lighting, a
home security system, a smart meter, etc. A mobile apparatus, such
as the UEs 115, may be able to communicate with macro eNBs, pico
eNBs, femto eNBs, relays, and the like. In FIG. 1, a lightning bolt
(e.g., the communication links 125) indicates wireless
transmissions between a UE and a serving eNB, which is an eNB
designated to serve the UE on the downlink and/or uplink, or
desired transmission between eNBs. Although backhaul communication
134 is illustrated as wired backhaul communications that may occur
between eNBs, it should be appreciated that backhaul communications
may additionally or alternatively be provided by wireless
communications.
[0034] LTE/-A utilizes orthogonal frequency division multiplexing
(OFDM) on the downlink and single-carrier frequency division
multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the
system bandwidth into multiple (K) orthogonal subcarriers, which
are also commonly referred to as tones, bins, or the like. Each
subcarrier may be modulated with data. In general, modulation
symbols are sent in the frequency domain with OFDM and in the time
domain with SC-FDM. The spacing between adjacent subcarriers may be
fixed, and the total number of subcarriers (K) may be dependent on
the system bandwidth. For example, K may be equal to 72, 180, 300,
600, 900, and 1200 for a corresponding system bandwidth of 1.4, 3,
5, 10, 15, or 20 megahertz (MHz), respectively. The system
bandwidth may also be partitioned into sub-bands. For example, a
sub-band may cover 1.08 MHz, and there may be 1, 2, 4, 8 or 16
sub-bands for a corresponding system bandwidth of 1.4, 3, 5, 10,
15, or 20 MHz, respectively.
[0035] FIG. 2 shows a block diagram of a design of a base
station/eNB 105 and a UE 115, which may be one of the base
stations/eNBs and one of the UEs in FIG. 1. For a restricted
association scenario, the eNB 105 may be the small cell eNB 105z in
FIG. 1, and the UE 115 may be the UE 115z, which in order to access
small cell eNB 105z, would be included in a list of accessible UEs
for small cell eNB 105z. The eNB 105 may also be a base station of
some other type. The eNB 105 may be equipped with antennas 234a
through 234t, and the UE 115 may be equipped with antennas 252a
through 252r.
[0036] At the eNB 105, a transmit processor 220 may receive data
from a data source 212 and control information from a
controller/processor 240. The control information may be for the
PBCH, PCFICH, PHICH, PDCCH, etc. The data may be for the PDSCH,
etc. The transmit processor 220 may process (e.g., encode and
symbol map) the data and control information to obtain data symbols
and control symbols, respectively. The transmit processor 220 may
also generate reference symbols, e.g., for the PSS, SSS, and
cell-specific reference signal. A transmit (TX) multiple-input
multiple-output (MIMO) processor 230 may perform spatial processing
(e.g., precoding) on the data symbols, the control symbols, and/or
the reference symbols, if applicable, and may provide output symbol
streams to the modulators (MODs) 232a through 232t. Each modulator
232 may process a respective output symbol stream (e.g., for OFDM,
etc.) to obtain an output sample stream. Each modulator 232 may
further process (e.g., convert to analog, amplify, filter, and
upconvert) the output sample stream to obtain a downlink signal.
Downlink signals from modulators 232a through 232t may be
transmitted via the antennas 234a through 234t, respectively.
[0037] At the UE 115, the antennas 252a through 252r may receive
the downlink signals from the eNB 105 and may provide received
signals to the demodulators (DEMODs) 254a through 254r,
respectively. Each demodulator 254 may condition (e.g., filter,
amplify, downconvert, and digitize) a respective received signal to
obtain input samples. Each demodulator 254 may further process the
input samples (e.g., for OFDM, etc.) to obtain received symbols. A
MIMO detector 256 may obtain received symbols from all the
demodulators 254a through 254r, perform MIMO detection on the
received symbols if applicable, and provide detected symbols. A
receive processor 258 may process (e.g., demodulate, deinterleave,
and decode) the detected symbols, provide decoded data for the UE
115 to a data sink 260, and provide decoded control information to
a controller/processor 280.
[0038] On the uplink, at the UE 115, a transmit processor 264 may
receive and process data (e.g., for the PUSCH) from a data source
262 and control information (e.g., for the PUCCH) from the
controller/processor 280. The transmit processor 264 may also
generate reference symbols for a reference signal. The symbols'
from the transmit processor 264 may be precoded by a TX MIMO
processor 266 if applicable, further processed by the modulators
254a through 254r (e.g., for SC-FDM, etc.), and transmitted to the
eNB 105. At the eNB 105, the uplink signals from the UE 115 may be
received by the antennas 234, processed by the demodulators 232,
detected by a MIMO detector 236 if applicable, and further
processed by a receive processor 238 to obtain decoded data and
control information sent by the UE 115. The processor 238 may
provide the decoded data to a data sink 239 and the decoded control
information to the controller/processor 240.
[0039] The controllers/processors 240 and 280 may direct the
operation at the eNB 105 and the UE 115, respectively. The
controller/processor 240 and/or other processors and modules at the
eNB 105 may perform or direct the execution of various processes
for the techniques described herein. The controllers/processor 280
and/or other processors and modules at the UE 115 may also perform
or direct the execution of the functional blocks illustrated in
FIG. 4, and/or other processes for the techniques described herein.
The memories 242 and 282 may store data and program codes for the
eNB 105 and the UE 115, respectively, A scheduler 244 may schedule
UEs for data transmission on the downlink and/or uplink.
[0040] Attention has been given to utilizing higher frequency
carriers for enabling higher data rate communications. In
particular, millimeter-wave wireless communication systems (e.g.,
operating at 28 GHz, 60 GHz, and greater) have the potential of
providing much higher data rates compared to systems operating in
the sub-6 GHz frequencies. Moreover, there remains availability of
large contiguous spectrum in these bands in many regions and
jurisdictions.
[0041] The use of such high frequency carriers, such as
millimeter-wave, in wireless communication systems is not, however,
without challenges. For example, millimeter-wave communications
suffer from very high attenuation of the transmitted signal as
compared with sub-6 GHz signal transmissions. Moreover,
millimeter-wave signals are highly susceptible to blockage (e.g.,
due to obstacles, such as buildings, foliage, terrain, etc., in the
signal path) due to the small wavelength of the signals,
[0042] Although beamforming might be performed (e.g., at Tx and/or
Rx antennas) in an attempt to counteract the signal attenuation or
to provide directional beams in order to best utilize the channel,
the use of beamforming with respect to high frequency carriers
(e.g., millimeter-wave) in some wireless communication systems
(e.g., many cellular communication system configurations) presents
its own challenges. For example, the use of beamforming creates a
challenge for paging, such as in wireless communication systems
where paging is implemented to wake up idle/sleep-mode UEs that
only listen at periodic intervals. In particular, where the UE
location is unknown to the network, especially with a long,
sleep-cycle, it is difficult to determine the direction in which to
beamform the paging signal for a particular UE. Although it may be
possible to sweep (e.g., azimuthally) the beamforming direction,
for the paging signal, it is desirable to keep UE wake-up time as
low as possible at each paging cycle; but enough time must be
allowed to sweep through the possible Tx and Rx beamforming
directions so the can read the page. Further, concurrent
transmission/reception of multiple beam directions implies
replicating the analog beamforming units and is thus expensive in
equipment cost and thus also undesirable.
[0043] Referring again to FIG. 1, in operation according to aspects
of the disclosure, various of the communication devices (e.g., one
or more of eNBs 105 and/or UEs 115) of wireless network 100 are
adapted to utilize high frequency carriers, such as millimeter-wave
(e.g., one or more frequency band within 28 GHz-300 GHz), for
implementing wireless communications. Circuitry of the
communication devices participating in such high frequency
communications may implement beamforming with respect to the high
frequency wireless signals, such as to accommodate signal
attenuation associated with the use of high frequency carriers, to
facilitate increased channel capacity, to avoid or mitigate
interference, etc. For example, one of eNBs 105 may implement
beamforming with respect to signal transmissions (i.e., downlink
transmission beamforming) and/or receiving signals (i.e., uplink
receiving beamforming). Additionally or alternatively, one or more
of UEs 115 may implement beamforming with respect to signal
transmissions (i.e., uplink transmission beamforming) and/or
receiving signals (i.e., downlink receiving beamforming). Such
transmission beamforming may be provided through MIMO processor 230
performing precoding (e.g., under control of controller/processor
240) on signals to be transmitted by eNB 105 (e.g., downlink
signals) and/or MIMO processor 226 performing precoding (e.g.,
under control of controller/processor 280) on signals to be
transmitted by UE 115). Receiving beamforming may be provided
through MIMO detector 236 performing spatial decoding (e.g., under
control of controller/processor 240) on signals received by eNB 105
(e.g., uplink signals) and/or MIMO detector 256 performing spatial
decoding (e.g., under control of controller/processor 280) on
signals received by UE 115 (e.g., downlink signals).
[0044] In accordance with aspects of the disclosure, devices of
wireless network 100 implement paging, such as to wake up
idle/sleep-mode ones of UEs 115. To conserve power, UEs 115 may
operate to only listen at periodic intervals for such paging
signals (e.g., when operating in an idle or sleep mode).
Accordingly, one or more devices of wireless network 100 are
adapted according to concepts herein to employ robust and efficient
paging techniques facilitating the use of beamforming in
association with high frequency communications. For example, paging
techniques implemented according to aspect of the disclosure enable
receiving a paging signal transmitted using a high frequency
carrier (e.g., millimeter-wave) with transmission beamforming
and/or with receiving beamforming.
[0045] Generally in beamforming scenarios there is a tradeoff
between beam range and beam spatial width/angle. In particular,
with respect to both transmitter and receiver beamforming, a
wide-angle beam will have lower penetration (e.g., less distance
from the beamforming device) into a service area while providing
larger azimuthal coverage (e.g., broader radial spread) of the
service area. Narrow beams, however, provide higher penetration
(e.g., more distance from the beamforming device) into a service
area while providing lower azimuthal coverage (e.g., narrower
radial spread). This is illustrated in FIG. 3, wherein exemplary
beams 310a and 310b, as may have been transmission or receive
beamformed by eNB 105a, are relatively narrow beams (e.g.,
azimuthal beam width less than 30.degree., such as 10.degree.
azimuthal beams) providing penetration to the edge of call 110a. In
contrast, exemplary beam 310c, also as may have been transmission
or receive beamformed by eNB 105a, is a relatively broad beam
(e.g., azimuthal beam width greater than 60.degree., such as
120.degree. azimuthal beams) providing penetration appreciably
short of the edge of cell 110a.
[0046] Although various beam formed by eNB 105a are shown in FIG.
3, it should be understood that UEs (e.g., UEs 115a and 115b) may
likewise form various beams. For example, the UEs may be capable of
forming beams having configurations (e.g., width and gain), or some
subset thereof, corresponding to the beams a corresponding eNB is
capable of forming. Beamforming by the UEs is not, however,
illustrated in FIG. 3 for simplicity of the drawing and to avoid
confusing illustrations.
[0047] As can be appreciated from the illustration of FIG. 3, use
of beam 310c for transmission of a paging signal by eNB 105a,
although providing relatively large azimuthal coverage (e.g.,
greater than 60.degree. azimuthal coverage) within cell 110a,
illuminates UE 115a but fails to illuminate UE 115b. Accordingly,
where the paging signal is intended for UE 115b, its transmission
using beam 310c is unlikely to result in waking UE 115b from an
idle or sleep mode. In contrast, beam 310b illuminates UE 115b (but
not UE 115a), and thus a paging signal intended for UE 115b
transmitted using beam 310c may result in waking UE 115B from an
idle or sleep mode. However, with UE 115b operating in an idle or
sleep mode (e.g., only listening for paging or other relevant
signals at periodic intervals), eNB 105a may not have sufficient
information regarding the location of UE 115b to know to beamform
beam 310b. For example, eNB 105a may instead beamform a beam in a
different azimuthal direction (e.g., beam 310a) that does not
illuminate UE 115b.
[0048] Devices of wireless network 100 are therefore adapted
according to concepts herein to implement paging in multiple stages
to facilitate the use of beamforming in association with high
frequency (e.g., 6 GHz and above) communications. For example, eNB
105a (e.g., operating under control of multiple stage paging logic
implemented by controller/processor 240) operable in accordance
with aspects herein may provide multiple paging stages, wherein
each paging stage implements different beamforming attributes
(e.g., picking one point on the above tradeoff).
[0049] In implementation of a multiple paging stage technique
according to aspects of the present disclosure, it is understood
that UEs (e.g., UE 115a relatively near the cell center) near the
transmitter (e.g., eNB 105a) may be reached even with a spatially
diffuse beam (e.g., beam 310c). Using a spatially narrow beam
(e.g., beam 310a) in this case may cause increased wake-up time to
scan multiple beam directions (e.g., azimuthally sweeping the beam,
or selecting different beam facing angles (the azimuthal angle at
which the direction of the primary lobe of the beam is directed or
centered), until the UE is illuminated). Moreover, the extra gain
from the narrow beam is likely unnecessary due to the UE being near
the transmitter. However, UEs (e.g., UE 115b relatively near the
cell edge) further away from the transmitter (e.g., eNB 105a) may
require more beamforming gain (e.g., as provided by beam 310b) in
order to be illuminated. In particular, the further away the UE is
from the transmitter, generally the more the beamforming gain
needed, and correspondingly there may be a need to scan more number
of narrow beams.
[0050] In accordance with aspects of a multiple paging stage
technique, information regarding the location and/or operation of
the devices is taken into account in implementing the multiple
stage paging. For example, a UE (e.g., UE 115a or UE 115b) and/or
eNB (e.g., eNB 105a) may be aware of the distance between them
(e.g., based upon signal strength information, signal to noise
ratio, etc.), although the direction may be completely unknown. A
multiple stage paging technique may use such distance information
to determine (e.g., through operation of logic of
controller/processor 240 and/or logic of controller/processor 280)
that the spatially broadest beams that will cover that distance are
to be formed (e.g., at the eNB for transmitting and/or the UE for
receiving), wherein the azimuthal direction of the beam may then be
swept until the UE is illuminated or all directions are covered.
For example, where distance information is known with respect to UE
115a, logic of controller/processor 240 may determine that
beamforming to provide a beam configuration (e.g., width and gain)
corresponding to that of beam 310c is to be implemented, whereby
one or more beams having the determined configuration may be swept
azimuthally. Similarly, where distance information is known with
respect to UE 115b, logic of controller/processor 240 may determine
that beamforming to provide a beam configuration (e.g., width and
gain) corresponding to that of beam 310b is to be implemented,
whereby one or more beams having the determined configuration may
be swept azimuthally. The use of such an appropriately broad beam
for transmitting the paging signal provides for illuminating the
desired UE with the paging signal transmission using a minimal
number of directions to be swept by the beam.
[0051] It should be appreciated, however, that such information may
not always be available for use in implementing the multiple stage
paging according to aspects of the disclosure. For example, both
distance and direction information may be unknown with respect to a
wireless communication device pair (e.g., eNB 105a and UE 115a or
115b). In operation of a multiple stage paging technique, the
distance may be assumed to be the worst case distance (e.g., UE
disposed at the cell edge, such as UE 115b) and the spatially
broadest beams that will cover that distance (e.g., beams having
width and gain corresponding to that of beams 310a and 310b) are to
be formed. For example, where distance information is not known
with respect to UE 115a, logic of controller/processor 240 may
determine that beamforming to provide a beam configuration (e.g.,
width and gain) corresponding to that of beams 310a and 310b is to
be implemented, whereby one or more beams having the determined
configuration may be swept azimuthally until the UE is illuminated
or all directions are covered. The foregoing operation, selecting a
beam configuration for the worst case distance is, however,
suboptimal if the distance is not in fact worst case.
[0052] Accordingly, a multiple stage paging technique may operate
to initially select a broad beam configuration (e.g.,
omnidirectional beam, 180.degree. beam, 120.degree. beam, etc.) and
transmit a paging signal using the selected beam (e.g., scanning
the beam where less than the service area is illuminated by the
selected beam). Thereafter, if the desired UE fails to provide a
page response, the multiple stage paging technique may operate to
select a more narrow beam configuration and transmit the paging
signal using the selected beam (e.g., scanning the beam). Selection
of an iteratively more narrow beam configuration and the
transmission of the paging signal may, for example, be repeated
until the desired UE provides a page response, the most narrow beam
configuration (e.g., a predetermined minimum beam width selected
for multiple stage paging, a minimum beam width achievable by the
beam forming circuitry, etc.) has been selected and scanned, or a
timeout has been reached.
[0053] Additionally or alternatively, a multiple stage paging
technique may operate to implement a probabilistic approach
according to aspects of the present disclosure. For example, given
a prior probability distribution of UE location within the cell,
and a sequence of beams of varying spatial angle and direction used
at the eNB and/or UE, the resulting mean time to successfully
decode the paging signal can be computed. Logic of
controller/processor 240 and/or controller/processor 280 may be
adapted to optimize the beam sequence to minimize this mean
decoding time. For example, the logic may estimate the prior
probability distribution of the UE location based on previous
transmissions between the UE and eNB and select a sequence of
beamforming configurations to probabilistically result in the UE
receiving the paging signal within a calculated mean time. It
should be appreciated that such an approach may suffer errors due
to inaccuracies in the probability estimates (e.g., the UE and eNB
could have different estimates, either or both of which could be
inaccurate). However, assuming a probability uniform within the
cell provides a robust approach against these errors. For suitable
path-loss models, a multiple stage paging technique operable to
scan all beam directions with progressively narrower beams may be
optimal in such a case.
[0054] Multiple stage paging techniques according to aspects of the
present disclosure may be utilized in combination with further
techniques to improve paging efficiency. For example, in addition
to or in the alternative to using beamforming gain to reach
cell-edge users, a multiple stage paging technique may utilize a
lower code-rate (e.g., higher redundancy in a forward error
correction code (FEC) used for transmitting data), and thus avoid
having to sweep multiple beam directions or minimizing the number
of beam directions swept and/or minimizing the number of different
beam configurations utilized in attempting to communicate the
paging signal. For example, a multiple stage paging technique may
use low code-rate (high overhead/redundancy) paging messages to
reach cell-edge UEs (e.g., UE 115b) that do not send a page
response after the initial sequence of beams. In such
implementations, low code-rate pages on omnidirectional (or
wide-angled) beams may be utilized as an alternative to shorter
pages sent sequentially on multiple narrower beams. In operation
according to some multiple stage paging implementations, downlink
channel estimates (e.g., downlink SINR-based criterion) may be used
in determining whether the UE listens to the "regular" pages (e.g.,
encoded with a standard code-rate) or the low-code-rate pages.
[0055] As another example of further techniques that may be
utilized in combination with a multiple stage paging technique
according to aspects of the disclosure, multiple stage paging may
not only be implemented with respect to blind paging signal
transmission, but may additionally or alternatively be implemented
in combination with an on-demand paging technique. In an on-demand
paging technique utilized according to aspects of the present
disclosure, at a paging cycle wake-up, the UE may operate to send
the network a ready-to-be-paged transmission (e.g., a data packet,
symbol, bit, flag, or other indicator that the UE is prepared
and/or standing by to be paged). Such transmission of a
ready-to-be-paged indication may be utilized (e.g., by logic of
controller/processor 240) to help the network to determine the UE's
location and/or distance and thus choose the beamforming
configuration (e.g., direction and/or gain) appropriately when
transmitting the paging signal. The ready-to-be-paged transmission
implemented according to some aspects includes the UE ID, and may
itself be sent on multiple beams to facilitate the eNB to receiving
the indication.
[0056] It can be understood from the discussion above regarding
FIG. 3, UEs sufficiently near the cell center (e.g., UE 115a) may
not require the overhead of the aforementioned ready-to-be-paged
indication. In some scenarios, UEs may be blindly paged even with
an omnidirectional or wide-angled beam from the eNB. Thus, the
overhead for UE's transmission of ready-to-be-paged indications can
be reduced in accordance with aspects of the disclosure. For
example, a UE may, at a paging cycle wake-up, first attempt
receiving a page on an omnidirectional or wide-angled beam (e.g.,
120.degree. beam), and transmit the ready-to-be-paged indication
only if this reception fails (e.g., broadcast paging fails). The
eNB may operate to listen for either a page response or the
ready-to-be-paged indication, whereby upon hearing the latter
indication the eNB re-pages the UE using a refined sequence of
beams based on this indication. The ready-to-be-paged indication
may thus tell the eNB that narrower beams should be used in paging
the UE.
[0057] It should be appreciated, however, that the foregoing UE's
page reception may have failed because there was no page sent by
the network. In operation according to some aspects of the
disclosure, the UE may attempt to identify this scenario (e.g.,
through operation of logic of controller/processor 280) based on
downlink channel estimation (e.g., signal to interference plus
noise ratio (SINR)) using the beam reference signals. Where the UE
determines (e.g., if the downlink SINR is above a threshold) that
page reception failed during a paging cycle wake-up because there
was no page sent, the UE may operate to skip transmission of the
ready-to-be-paged indicator. In accordance with aspects herein, the
paging cycles may be designed to be closely aligned with the
periodicity of the reference signals, to aid in such channel
estimation (e.g., downlink SINR estimation). Additionally or
alternatively, the UE may operate to skip transmission of the
aforementioned ready-to-be-paged indication in low mobility
situations, such as where the multiple stage paging technique uses
the last known UE location in determining a beam configuration for
the paging signal. It should be appreciated that the last known
location is an example of a-priori probability distribution of the
UE, wherein a multiple stage paging technique implementing a
probabilistic approach according to aspects of the present
disclosure may initially select a beam in the direction of the UE's
prior location for transmitting a paging signal. The UE may
additionally or alternatively attempt to receive the paging signal
using a beam in that direction. If unsuccessful, and the UE
determines (using sensors, prior transmissions, etc.) that it had
not moved, the UE may operate to conclude that there was no paging
signal transmitted, and thus skip transmitting the
ready-to-be-paged indication.
[0058] Referring now to FIG. 4, flow 400 illustrating operation of
a multiple stage paging technique implemented according to aspects
of the present disclosure is shown. The processes of flow 400 may,
for example, be implemented by logic of eNB 105 and/or UE 115
(e.g., logic of controller/processor 240 and/or
controller/processor 280).
[0059] At block 401 of the illustrated implementation, a sequence
of a plurality of beam configurations for communicating a paging
signal is selected (e.g., by multiple stage paging logic
implemented by controller/processor 240 of eNB 105 and/or by
multiple stage paging logic implemented by controller/processor 280
of UD 115). For example, the plurality of beam configurations may
comprise beam configurations for forming beams of varying angular
widths as described above. The particular sequence of beam
configurations may be selected using information regarding the
location of the UE, a known prior location of the UE, movement of
the UE, the distance between the UE and the basestation, the
probability distribution of UE location, etc. (e.g., as may be
stored within memory 242 of eNB 105 and/or memory 282 of UE 115, as
may be obtained by multiple stage paging logic implemented by
controller/processor 240 of eNB 105 and/or by multiple stage paging
logic implemented by controller/processor 280 of UD 115, etc.).
[0060] Multiple stage paging logic operates to select a beam
configuration of the plurality of beam configurations at block 402
of the illustrated implementation. For example, a first beam
configuration (e.g., a beam configuration providing a spatially
broadest beam that will cover a distance between the eNB and UE, a
beam configuration providing the broadest beam of the plurality of
beam configurations, a beam configuration providing a beam
probabilistically determined to result in the UE receiving the
paging signal, etc.) of the beam configurations for attempting
communication of the paging signal between the eNB and UE may be
selected.
[0061] At block 403 of the illustrated implementation multiple
stage paging logic operates to select a facing angle (the azimuthal
angle at which the direction of the primary lobe of the beam is
directed or centered) for a beam formed using the selected beam
configuration. For example, a first facing angle (e.g., a facing
angle in the direction of a last known location of the UE, a facing
angle in the direction of a predicted location of the UE, etc.) for
attempting communication of the paging signal between the eNB and
UE may be selected.
[0062] Communication of the paging signal using a beam formed
according to the selected beam configuration at the selected facing
angle is attempted at block 404 of the illustrated implementation.
For example, the eNB may operate to form a beam at the selected
facing angle using the selected beam configuration and to transmit
the paging signal using the formed beam (e.g., using transmit
processor 220, TX MIMO processor 230, one or more of mods 232a
through 232t, and one or more of antennas 234a through 234t
operating under control of controller/processor 240 of eNB 105).
Additionally or alternatively, the UE may operate to form a beam at
the selected facing angle using the selected beam configuration and
attempt to receive the paging signal using the formed beam (e.g.,
using one or more of antennas 252a through 252r, one or more of
demods 254a through 252r, MIMO detector 256, and receive processor
258 operating under control of controller/processor 280 of UE
115).
[0063] A determination is made regarding whether the paging signal
has successfully been communicated between the eNB and the UE at
block 405 of the illustrated implementation. For example, upon
receiving the paging signal the UE (e.g., using transmit processor
264, TX MIMO processor 266, one or more of mods 254a through 254r,
and one or more of antennas 252a through 252r operating under
control of controller/processor 280 of UE 115) may provide a paging
response to the eNB (e.g., using one or more of antennas 234a
through 234t, one or more of demods 232a through 232t, MIMO
detector 236, and receive processor 238 operating under control of
controller/processor 240 of eNB 105), whereby each such device
determines that the paging signal has been successfully
communicated. If it is determined that the paging signal has been
successfully communicated, processing according to the illustrated
implementation proceeds to block 406 wherein wireless
communications appropriate to the page are conducted. However, if
it is determined that the paging signal has not been successfully
communicated, processing according to the illustrated
implementation proceeds to block 407.
[0064] A determination is made (e.g., by multiple stage paging
logic implemented by controller/processor 240 of eNB 105 and/or by
multiple stage paging logic implemented by controller/processor 280
of UD 115) at block 407 of the illustrated implementation regarding
whether all facing angles (e.g., all facing angles of a plurality
of facing angles, all facing angles determined to provide coverage
of a service area, etc.) have been used for the selected beam
configuration. If it is determined that not all of the facing
angles have been used, processing according to the illustrated
implementation returns to block 403 wherein a next facing angle is
selected for a beam of the selected beam configuration. However, if
it is determined that all facing angles have been used, processing
according to the illustrated implementation proceeds to block
408.
[0065] A determination is made (e.g., by multiple stage paging
logic implemented by controller/processor 240 of eNB 105 and/or by
multiple stage paging logic implemented by controller/processor 280
of UD 115) at block 408 of the illustrated implementation regarding
whether all beam configurations have been used for the selected
sequence of beam configurations. If it is determined that not all
of the beam configurations have been used, processing according to
the illustrated implementation returns to block 402 wherein a next
beam configuration of the sequence of beam configurations is
selected. However, if it is determined that all beam configurations
have been used, processing according to the illustrated
implementation proceeds to block 409 wherein processing
commensurate with no paging signal communication is performed
(e.g., a determination may be made that no paging signal was
communicated and a next epoch of a paging cycle may be awaited, a
UE may determine that a ready-to-be-paged indication is to be
communicated, a different sequence of beam configurations for
attempting paging signal communication may be selected and flow 400
repeated, etc.).
[0066] It should be appreciated that the processes of boxes 402-408
(as indicated by box 410) provide for iteratively using beam
configurations to attempt to successfully communicate the paging
signal between the eNB and the UE. Iteratively using beam
configurations according to flow 400 may, for example, be continued
(e.g., by multiple stage paging logic implemented by
controller/processor 240 of eNB 105 and/or by multiple stage paging
logic implemented by controller/processor 280 of UD 115) until
either each iteration for each beam configuration has used its
respective different angular width beam configuration at each
facing angle of the plurality of facing angles or the paging signal
has successfully been communicated between the pair of wireless
devices.
[0067] The particular beam configuration needed by the eNB at a
given stage in the paging procedure may be different from the beam
configuration needed with respect to other signals (e.g., broadcast
signals, data to other UEs, etc.). Creating multiple beams
simultaneously may require extra complexity in the RF part of the
transmitter. For data transmissions, this complexity can be
contained by time division multiplex (TDM) scheduling, wherein only
one UE is scheduled at any given time. However, paging messages may
be short and TDM scheduling of pages can waste eNB resources.
Accordingly, in operation according to some aspects of the
disclosure, paging messages to multiple UEs that require or may
otherwise use similar beam configurations for paging signal
transmission may be collected together and sent simultaneously as a
group on the same beam.
[0068] Those of skill in the art would understand that information
and signals may be represented using any of a variety of different
technologies and techniques. For example, data, instructions,
commands, information, signals, bits, symbols, and chips that may
be referenced throughout the above description may be represented
by voltages, currents, electromagnetic waves, magnetic fields or
particles, optical fields or particles, or any combination
thereof.
[0069] The functional blocks and modules in FIGS. 5-7 may comprise
processors, electronics devices, hardware devices, electronics
components, logical circuits, memories, software codes, firmware
codes, etc., or any combination thereof.
[0070] Those of skill would further appreciate that the various
illustrative logical blocks, modules, circuits, and algorithm steps
described in connection with the disclosure herein may be
implemented as electronic hardware, computer software, or
combinations of both. To clearly illustrate this interchangeability
of hardware and software, various illustrative components, blocks,
modules, circuits, and steps have been described above generally in
terms of their functionality. Whether such functionality is
implemented as hardware or software depends upon the particular
application and design constraints imposed on the overall system.
Skilled artisans may implement the described functionality in
varying ways for each particular application, but such
implementation decisions should not be interpreted as causing a
departure from the scope of the present disclosure. Skilled
artisans will also readily recognize that the order or combination
of components, methods, or interactions that are described herein
are merely examples and that the components, methods, or
interactions of the various aspects of the present disclosure may
be combined or performed in ways other than those illustrated and
described herein.
[0071] The various illustrative logical blocks, modules, and
circuits described in connection with the disclosure herein may be
implemented or performed with a general-purpose processor, a
digital signal processor (DSP), an application specific integrated
circuit (ASIC), a field programmable gate array (FPGA) or other
programmable logic device, discrete gate or transistor logic,
discrete hardware components, or any combination thereof designed
to perform the functions described herein. A general-purpose
processor may be a microprocessor, but in the alternative, the
processor may be any conventional processor, controller,
microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0072] The steps of a method or algorithm described in connection
with the disclosure herein may be embodied directly in hardware, in
a software module executed by a processor, or in a combination of
the two. A software module may reside in RAM memory, flash memory,
ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a
removable disk, a CD-ROM, or any other form of storage medium known
in the art. An exemplary storage medium is coupled to the processor
such that the processor can read information from, and write
information to, the storage medium. In the alternative, the storage
medium may be integral to the processor. The processor and the
storage medium may reside in an ASIC. The ASIC may reside in a user
terminal. In the alternative, the processor and the storage medium
may reside as discrete components in a user terminal.
[0073] In one or more exemplary designs, the functions described
may be implemented in hardware, software, firmware, or any
combination thereof. If implemented in software, the functions may
be stored on or transmitted over as one or more instructions or
code on a computer-readable medium. Computer-readable media
includes both computer storage media and communication media
including any medium that facilitates transfer of a computer
program from one place to another. Computer-readable storage media
may be any available media that can be accessed by a general
purpose or special purpose computer. By way of example, and not
limitation, such computer-readable media can comprise RAM, ROM,
EEPROM, CD-ROM or other optical disk storage, magnetic disk storage
or other magnetic storage devices, or any other medium that can be
used to carry or store desired program code means in the form of
instructions or data structures and that can be accessed by a
general-purpose or special-purpose computer, or a general-purpose
or special-purpose processor. Also, a connection may be properly
termed a computer-readable medium. For example, if the software is
transmitted from a website, server, or other remote source using a
coaxial cable, fiber optic cable, twisted pair, or digital
subscriber line (DSL), then the coaxial cable, fiber optic cable,
twisted pair, or DSL, are included in the definition of medium.
Disk and disc, as used herein, includes compact disc (CD), laser
disc, optical disc, digital versatile disc (DVD), floppy disk and
blu-ray disc where disks usually reproduce data magnetically, while
discs reproduce data optically with lasers. Combinations of the
above should also be included within the scope of computer-readable
media.
[0074] As used herein, including in the claims, the term "and/or,"
when used in a list of two or more items, means that any one of the
listed items can be employed by itself, or any combination of two
or more of the listed items can be employed. For example, if a
composition is described as containing components A, B, and/or C,
the composition can contain A alone; B alone; C alone; A and B in
combination; A and C in combination; B and C in combination; or A,
B, and C in combination. Also, as used herein, including in the
claims, "or" as used in a list of items prefaced by "at least one
of" indicates a disjunctive list such that, for example, a list of
"at least one of A, B, or C" means A or B or C or AB or AC or BC or
ABC (i.e., A and B and C) or any of these in any combination
thereof.
[0075] The previous description of the disclosure is provided to
enable any person skilled in the art to make or use the disclosure.
Various modifications to the disclosure will be readily apparent to
those skilled in the art, and the generic principles defined herein
may be applied to other variations without departing from the
spirit or scope of the disclosure. Thus, the disclosure is not
intended to be limited to the examples and designs described herein
but is to be accorded the widest scope consistent with the
principles and novel features disclosed herein.
* * * * *