U.S. patent application number 17/556148 was filed with the patent office on 2022-05-26 for local oscillator synchronization for coherent phased-array system.
This patent application is currently assigned to AT&T Intellectual Property I, L.P.. The applicant listed for this patent is AT&T Intellectual Property I, L.P., University of Notre Dame du Lac. Invention is credited to Ralf Bendlin, Jonathan David Chisum, Aditya Chopra, Nicholas Joseph Estes, Kang Gao, Bertrand Martyn Hochwald.
Application Number | 20220166458 17/556148 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-26 |
United States Patent
Application |
20220166458 |
Kind Code |
A1 |
Chopra; Aditya ; et
al. |
May 26, 2022 |
LOCAL OSCILLATOR SYNCHRONIZATION FOR COHERENT PHASED-ARRAY
SYSTEM
Abstract
Aspects of the subject disclosure may include, for example,
generating multiple digital reference pulses synchronously to a
master oscillator, selectively switching the multiple digital
reference pulses, and providing the switched pulses to multiple
radio modules operating within a millimeter wave spectrum. For each
radio module, counting cycles of an adjustable LO output signal
occurring between consecutive pulses of the switched digital
reference pulses, determining a difference between the count value
and a reference value, and adjusting the adjustable LO according to
the difference. A resulting corrected LO signal is synchronized to
the master oscillator. Other embodiments are disclosed.
Inventors: |
Chopra; Aditya; (Austin,
TX) ; Bendlin; Ralf; (Cedar Park, TX) ; Estes;
Nicholas Joseph; (South Bend, IN) ; Gao; Kang;
(San Diego, CA) ; Hochwald; Bertrand Martyn;
(South Bend, IN) ; Chisum; Jonathan David; (South
Bend, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AT&T Intellectual Property I, L.P.
University of Notre Dame du Lac |
Atlanta
South Bend |
GA
IN |
US
US |
|
|
Assignee: |
AT&T Intellectual Property I,
L.P.
Atlanta
GA
University of Notre Dame du Lac
South Bend
IN
|
Appl. No.: |
17/556148 |
Filed: |
December 20, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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17102666 |
Nov 24, 2020 |
11239877 |
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17556148 |
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International
Class: |
H04B 1/50 20060101
H04B001/50; H04B 1/00 20060101 H04B001/00 |
Goverment Interests
GOVERNMENT LICENSE RIGHTS
[0002] This invention was made with government support under
ECCS1731056 awarded by the National Science Foundation. The
government has certain rights in the invention.
Claims
1. A system, comprising: a digital pulse generator adapted to
provide a plurality of digital reference pulses synchronously
according to a radio frequency (RF) reference of a master
oscillator, wherein a pulse repetition rate of a digital reference
pulse of the plurality of digital reference pulses is substantially
less than a frequency of the RF reference; and a switch in
communication with the digital pulse generator and adapted to
selectively provide a switched digital reference pulse of the
plurality of digital reference pulses to a plurality of radio
modules adapted to operate in a millimeter wave spectrum, wherein
the switched digital reference pulse facilitates generation of an
error signal at each of a plurality of radio modules according to a
difference between a count of cycles of an adjustable local
oscillator (LO) between successive pulses of the switched digital
reference pulse and a reference value, an adjustable LO being
adapted to provide a corrected LO signal responsive to the error
signal, and wherein the corrected LO signal is synchronized to the
master oscillator.
2. The system of claim 1, wherein the plurality of radio modules
comprises 100 radio modules, each radio module of the plurality of
radio modules being synchronized to the master oscillator.
3. The system of claim 1, wherein each radio module of the
plurality of radio modules further comprises a modulator in
communication with the adjustable LO, and wherein the modulator is
adapted to one of modulate, demodulate or both modulate and
demodulate a millimeter wave signal based on the corrected LO
signal.
4. The system of claim 3, wherein each radio module of the
plurality of radio modules further comprises one of an
analog-to-digital converter (ADC), a digital-to-analog converter
(DAC), or both an ADC and a DAC coupled between a baseband digital
processor and the modulator.
5. The system of claim 1, further comprising a loop filter in
communication between an error detector that provides the error
signal and the adjustable LO, wherein the loop filter operates upon
the error signal to obtain a filtered error signal, and wherein the
adjustable LO is adapted to provide the corrected LO signal
responsive to the filtered error signal.
6. The system of claim 5, wherein the loop filter comprises an
integrator adapted to integrate the error signal to obtain an
integrated error signal, the adjustable LO being adapted to provide
the corrected LO signal responsive to the integrated error
signal.
7. The system of claim 1, wherein each radio module of the
plurality of radio modules further comprises a frequency multiplier
in communication with the adjustable LO, wherein the frequency
multiplier provides a multiplied corrected LO signal comprising a
multiple of the corrected LO signal operating within the millimeter
wave spectrum, and wherein the multiplied corrected LO signal is
coherent with another multiplied corrected LO signal of another
radio module of the plurality of radio modules.
8. The system of claim 7, wherein each radio module of the
plurality of radio modules further comprises a controllable phase
shifter, an antenna pattern of an antenna array in communication
with the plurality of radio modules being directed according to a
phase offset imparted by the controllable phase shifter.
9. The system of claim 8, wherein each radio module of the
plurality of radio modules further comprises a controllable
amplitude adjuster, an antenna pattern of the antenna array being
shaped according to an amplitude offset imparted by the
controllable amplitude adjuster.
10. A method, comprising: generating a plurality of digital
reference pulses synchronously according to a radio frequency (RF)
reference of a master oscillator, wherein a pulse repetition rate
of a digital reference pulse of the plurality of digital reference
pulses is substantially less than a frequency of the RF reference;
selectively switching the plurality of digital reference pulses to
obtain a plurality of switched digital reference pulses; and
providing the plurality of switched digital reference pulses to a
plurality of radio modules operating within a millimeter wave
spectrum the plurality of digital reference pulses countable at the
plurality of radio module according to a plurality of controllable
local oscillator (LO) output signals to obtain a plurality of count
values comparable with a reference value to obtain a plurality of
difference values, the plurality of controllable LOs adjustable
according to the plurality of difference values to obtain a
plurality of corrected LO signals synchronized to the master
oscillator.
11. The method of claim 10, wherein the plurality of radio modules
comprises 100 radio modules, each radio module of the plurality of
radio modules being synchronized to the master oscillator.
12. The method of claim 10, further comprising demodulating a
received millimeter wave signal according to a corrected LO signal
of the plurality of corrected LO signals to obtain a baseband
signal.
13. The method of claim 12, wherein the demodulating further
comprises down converting the received millimeter wave signal
according to the corrected LO signal of the plurality of corrected
LO signals to obtain a down-converted signal, the demodulating
applied to the down-converted signal.
14. The method of claim 12, further comprising converting the
baseband signal to a digital signal via an analog-to-digital
converter (ADC).
15. The method of claim 10, further comprising modulating a
corrected LO signal of the plurality of corrected LO signals
according to baseband information to obtain a modulated signal.
16. The method of claim 15, wherein the modulating further
comprises up converting an intermediate frequency signal according
to the corrected LO signal of the plurality of corrected LO signals
to obtain an up-converted signal operating within the millimeter
wave spectrum.
17. The method of claim 16, further comprising converting a digital
baseband signal to an analog signal via a digital-to-analog
converter (DAC).
18. A system, comprising: a digital pulse generator adapted to
provide a plurality of digital reference pulses according to a
radio frequency (RF) reference of a master oscillator, wherein a
pulse repetition rate of a digital reference pulse of the plurality
of digital reference pulses is substantially less than a frequency
of the RF reference; and a switch in communication with the digital
pulse generator that provides a respective digital reference pulse
of the plurality of digital reference pulses to each radio module
of a plurality of radio modules that are adapted to operate in a
millimeter wave spectrum, the respective digital reference pulse
countable at each radio module of the plurality of radio modules
according to a respective controllable local oscillator (LO) output
signal to obtain a respective count value comparable with a
reference value to obtain a difference, each respective
controllable LO being adapted to provide a corrected LO signal
responsive to the difference, the corrected LO signal being
coherent with other radio modules of the plurality of radio
modules.
19. The system of claim 18, wherein a dimension of a respective
radio module is no larger than a maximum dimension of a respective
antenna element, such that a size of each radio module is
determined according to the maximum dimension of the respective
antenna element.
20. The system of claim 18, wherein each radio module of the
plurality of radio modules comprises a respective mixer in
communication with the respective controllable LO and a respective
millimeter wave antenna, the respective mixer facilitating one of a
modulation, a demodulation, or both.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 17/102,666 filed on Nov. 24, 2020. The
contents of each of the foregoing is/are hereby incorporated by
reference into this application as if set forth herein in full.
FIELD OF THE DISCLOSURE
[0003] The subject disclosure relates to local oscillator
synchronization for coherent phased-array system.
BACKGROUND
[0004] The development of new wireless communications technologies
has traditionally been driven by a desire for higher data rates.
For example, in commercial cellular applications, rapid increases
in a number of end-users and complexity of mobile applications of
recent decades have demanded a wireless communications solution
that provides low latency while achieving high instantaneous data
rates in a complicated physical environment with an unknown (a
priori) number of users with unknown locations.
[0005] One solution to increase data rates includes moving to
higher carrier frequencies, e.g., including millimeter wave
frequencies operating at K-band and above, in which traditional
narrowband designs lead to high absolute operating bandwidths.
However, any move to such extreme frequencies does not come without
cost. One such approach, termed 5G New Radio (NR) marks a paradigm
shift from omnidirectional to directive communications as
higher-gain antennas are required to maintain a constant-power link
as the carrier frequency increases. Such requirements of high gain
are a consequence of the Friis equation, which states that, for
given antenna gain on transmit and receive, the receive power is
inversely proportional to the square of the operating frequency.
The current solution to this spatially-multiplexed paradigm is a
phased array.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Reference will now be made to the accompanying drawings,
which are not necessarily drawn to scale, and wherein:
[0007] FIG. 1 is a block diagram illustrating an exemplary,
non-limiting embodiment of a communications network in accordance
with various aspects described herein.
[0008] FIG. 2A is a block diagram illustrating an example,
non-limiting embodiment of a MIMO communication system functioning
within the communication network of FIG. 1 in accordance with
various aspects described herein.
[0009] FIG. 2B is a block diagram illustrating an example,
non-limiting embodiment of a MIMO radio functioning within the
communication network of FIG. 1 and the MIMO communication system
of FIG. 2A in accordance with various aspects described herein.
[0010] FIG. 2C is a block diagram illustrating an example,
non-limiting embodiment of a MIMO radio module functioning within
the communication network of FIG. 1 and the MIMO communication
system of FIG. 2A in accordance with various aspects described
herein.
[0011] FIG. 2D is planar view of an example, non-limiting
embodiment of a MIMO radio module functioning within the
communication network of FIG. 1 and the MIMO communication system
of FIG. 2A in accordance with various aspects described herein.
[0012] FIG. 2E is a block diagram illustrating an example,
non-limiting embodiment of a radio system including an antenna
array functioning within the communication network of FIG. 1 and
the MIMO communication system of FIG. 2A.
[0013] FIG. 2F is a block diagram illustrating an example,
non-limiting embodiment of a distributed, coherent LO system
functioning with the communication network of FIG. 1, the MIMO
communication system of FIG. 2A, and the radio system of FIG. 2E in
accordance with various aspects described herein.
[0014] FIG. 2G depicts a graphical representation of LO
synchronization signals according LO correction system functioning
with the communication network of FIG. 1, the MIMO communication
system of FIG. 2A, the radio system of FIG. 2E, and the
distributed, coherent LO system of FIG. 2F in accordance with
various aspects described herein.
[0015] FIG. 2H is a block diagram illustrating an example,
non-limiting embodiment of an LO correction system functioning with
the communication network of FIG. 1, the MIMO communication system
of FIG. 2A, the radio system of FIG. 2E, and the distributed,
coherent LO system of FIG. 2F in accordance with various aspects
described herein.
[0016] FIG. 2I depicts an illustrative embodiment of a process that
establishes synchronization of large numbers of LOs operating
within a millimeter wave system in accordance with various aspects
described herein.
[0017] FIG. 3 is a block diagram illustrating an example,
non-limiting embodiment of a virtualized communication network in
accordance with various aspects described herein.
[0018] FIG. 4 is a block diagram of an example, non-limiting
embodiment of a computing environment in accordance with various
aspects described herein.
[0019] FIG. 5 is a block diagram of an example, non-limiting
embodiment of a mobile network platform in accordance with various
aspects described herein.
[0020] FIG. 6 is a block diagram of an example, non-limiting
embodiment of a communication device in accordance with various
aspects described herein.
DETAILED DESCRIPTION
[0021] The subject disclosure describes, among other things,
illustrative embodiments for wireless communications systems in
general, and to next-generation wireless communications systems
with high-dimensional, low-resolution architectures for
power-efficient wireless communications in particular. Other
embodiments are described in the subject disclosure.
[0022] One or more aspects of the subject disclosure include a
system having multiple radio modules adapted to operate in a
millimeter wave spectrum, a master oscillator adapted to provide a
radio frequency (RF) reference, and a digital pulse generator in
communication with the master oscillator and adapted to provide a
group of digital reference pulses synchronously according to the RF
reference. A pulse repetition rate of a digital reference pulse is
substantially less than a frequency of the RF reference. The system
also includes a switch in communication with the digital pulse
generator and adapted to selectively provide a switched digital
reference pulse of the plurality of digital reference pulses to the
multiple radio modules. Each of the radio modules includes an
adjustable local oscillator (LO) adapted to provide an LO output
signal and a counter in communication with the switch and the
adjustable LO. The counter is adapted to count cycles of the LO
output signal occurring between consecutive pulses of the switched
digital reference pulse to obtain a count value. Each of the radio
modules also includes an error detector in communication with the
counter and the adjustable LO. The error detector is adapted to
generate an error signal according to a difference between the
count value and a reference value, wherein the adjustable LO is
adapted to provide a corrected LO signal responsive to the error
signal. The corrected LO signal is synchronized to the master
oscillator.
[0023] One or more aspects of the subject disclosure include a
process that includes generating multiple digital reference pulses
synchronized to an RF reference of a master oscillator. A pulse
repetition rate of a digital reference pulse of the multiple
digital reference pulses is substantially less than a frequency of
the RF reference. The multiple digital reference pulses are
selectively switched to obtain multiple switched digital reference
pulses. The multiple switched digital reference pulses are provided
to multiple radio modules operating within a millimeter wave
spectrum, wherein each of the radio modules includes an adjustable
LO. The process further includes counting cycles of an LO output
signal of the adjustable LO occurring between consecutive pulses of
the switched digital reference pulses to obtain a count value. A
difference is determined between the count value and a reference
value, and the adjustable LO is adjusted according to the
difference to obtain a corrected LO signal, wherein the corrected
LO signal is synchronized to the master oscillator.
[0024] One or more aspects of the subject disclosure include a
multiple input multiple output (MIMO) radio, which includes
multiple radio modules adapted to operate in a millimeter wave
spectrum, a master oscillator adapted to provide an RF reference,
and a digital pulse generator in communication with the master
oscillator. The digital pulse generator is adapted to provide
multiple digital reference pulses based on the RF reference. The
MIMO radio also includes a switch in communication with the digital
pulse generator and adapted to provide respective digital reference
pulses to each of the radio modules. Each radio module includes a
controllable LO adapted to provide an LO output signal and a
counter in communication with the switch and the controllable LO,
wherein the counter is adapted to count according to the LO output
signal and the respective digital reference pulses to obtain a
count value. Each radio module further includes a difference
detector in communication with the counter and the controllable LO,
wherein the difference detector is adapted to determine a
difference between the count value and a reference value. The
controllable LO is adapted to provide a corrected LO signal
responsive to the difference, wherein the corrected LO signal is
coherent with other radio modules of the multiple radio
modules.
[0025] High-resolution, high peak-to-average-power communication
modulation formats such as OFDM (LTE) have traditionally required
both the base station (BS) and user equipment (BE) to maintain a
high degree of linearity. An imposition of such linearity
requirements, however, limits efficiencies and indirectly a maximum
practical power output of a transmitter. Such linearity
requirements have also necessitated any mixing circuits as may be
used in either transmit or receive operation, to incorporate
high-powered local oscillators. Linearity in gain stages and low
noise amplifiers is also paramount. This ultimately results in a
system with inefficient amplification and high-power requirements.
In a massive MIMO deployment scenario, the power consumption of the
transceiver system scales roughly linearly with the number of
transmitter/receiver (Tx/Rx) elements, which can prove impractical
for systems employing high peak-to-average power ratio modulations
requiring traditional highly-linear design. This downside is
further compounded in the phased array system, which employs
high-resolution complex amplitude control, typically in the RF
chain, to achieve beamforming at the expense of power consumption
and efficiency.
[0026] The example embodiments disclosed herein use low-resolution,
e.g., single-bit or perhaps a few bit, transmitters and/or
receivers and/or transceivers as means of relaxing the linearity
and power requirements of next-generation wireless communications.
An easily replicable, low power, low cost, RF-in, bits-out one-bit
receiver cell forms the basic building block of a nonlinear MIMO
cellular system. This transceiver architecture enables simple
beamforming in the digital domain.
[0027] The devices, systems and techniques disclosed herein may be
applicable to any wireless communications application, but are
particularly suitable for high-frequency cellular communications
operating at frequencies within K-band and above K-band, at which
the propagation characteristics of microwave and millimeter-wave
signals typically rely on high-gain antennas and encourage spatial
multiplexing. The inherent spectral inefficiency of low-resolution
modulation schemes becomes less of a concern when fewer end users
are sharing identical space-bandwidth. Additionally, as the carrier
frequency increases, solid-state amplifiers are less able to
provide gain due to transistor parasitics, which result in a finite
maximum operating frequency that further increases complexity and
power consumption for a given output power. At least one
counterintuitive technique disclosed herein is to operate one or
more RF signal processing devices, such as LOs, signal combiners,
square law detectors and/or transistor amplifiers in their most
efficient nonlinear regime to reduce power consumption.
[0028] The illustrative examples provided herein include
ultra-low-power, low-complexity, scalable radio receivers, such as
the example MIMO radio cells. These radio cells exploit
nonlinearities in their devices and/or circuits to obtain very low
power consumption and ease of fabrication in a variety of
technologies for wide bandwidths and at very high carrier
frequencies. Such radio cell may include a receiver or a
transmitter or receiver and transmitter. In at least some
embodiments, the radio cell is configured to demodulate or to
modulate or to modulate and demodulate a single bit, or perhaps a
few bits, e.g., two bits per symbol. At least some of the
illustrative example radio cells disclosed herein include energy
detectors, such as envelope detectors and/or square law detectors
that utilize detection directly from a received RF carrier, without
requiring down-conversion and/or the use of mixers and/or local
oscillators, such as U.S. patent application Ser. No. 16/988,103,
entitled "Ultra-Low-Power Millimeter-Wave to Baseband Receiver
Module for Scalable Massive MIMO," which is incorporated herein by
reference in its entirety. Other illustrative example radio cells
disclosed herein include signal combiners adapted to convert phase
modulated signals, e.g., PSK signals, to amplitude modulated
signals, e.g., pulse amplitude modulated signals suitable for
detection by energy detectors, such as the aforementioned envelope
detectors and/or square law detectors, as disclosed in U.S. patent
application Ser. No. 17/103,152, entitled "Low-Resolution,
Low-Power, Radio Frequency Receiver," Attorney Docket No.
2020-0176_7785-2315A, which is also incorporated herein by
reference in its entirety. Beneficially, such single-bit receivers
and/or transmitters and/or transceivers relax linearity and power
requirements of next-generation wireless communications. The simple
radio cells disclosed herein are low power, low cost, easily
replicable RF-in, bits-out, low-bit receivers, e.g., one-bit
receivers, that form basic building block of a nonlinear MIMO
cellular system. It is understood that, without limitation, such
transceiver architectures enable simple beamforming in the digital
domain.
[0029] Referring now to FIG. 1, a block diagram is shown
illustrating an example, non-limiting embodiment of a
communications network 100 in accordance with various aspects
described herein. For example, communications network 100 can
facilitate in whole or in part receiving, by a first radio module
at a first location, a wireless MIMO signal, to obtain a first
received RF signal. Alternatively or in addition, the
communications network 100 may facilitate in whole or in part
transmitting, by the first radio module at a first location, a
wireless MIMO signal, to obtain a first transmitted RF signal.
[0030] The MIMO signal of a first received RF signal may include
information originating at a remote MIMO transmitter and conveyed
via a wireless channel. In at least some embodiments, e.g., for
on-off-keying (OOK) modulation, an envelope of the first received
RF signal may be detected by the first radio module without
requiring a local oscillator, to obtain a first detected baseband
signal. For phase modulated received RF signals, e.g., according to
phase-shift keying (PSK), including binary PSK (BPSk), differential
PSK (DPSK), and the like, a local oscillator may be mixed with the
first received RF signal to obtain a baseband signal that may be
detected using a square law detector, e.g., an envelope detector.
The first detected baseband signal is compared to a reference value
to obtain a first digital signal that is provided to a digital
processor. The digital processor also obtains a second digital
signal from a second radio module receiving the wireless MIMO
signal at a second location and determines an estimate of the
information originating at the remote MIMO transmitter according to
the first and second digital signals. In particular, a
communications network 125 is presented for providing broadband
access 110 to a plurality of data terminals 114 via access terminal
112, wireless access 120 to a plurality of mobile devices 124 and
vehicle 126 via base station or access point 122, voice access 130
to a plurality of telephony devices 134, via switching device 132
and/or media access 140 to a plurality of audio/video display
devices 144 via media terminal 142. In addition, communication
network 125 is coupled to one or more content sources 175 of audio,
video, graphics, text, and/or other media. While broadband access
110, wireless access 120, voice access 130 and media access 140 are
shown separately, one or more of these forms of access can be
combined to provide multiple access services to a single client
device (e.g., mobile devices 124 can receive media content via
media terminal 142, data terminal 114 can be provided voice access
via switching device 132, and so on).
[0031] The communications network 125 includes a plurality of
network elements (NE) 150, 152, 154, 156, etc., for facilitating
the broadband access 110, wireless access 120, voice access 130,
media access 140 and/or the distribution of content from content
sources 175. The communications network 125 can include a circuit
switched or packet switched network, a voice over Internet protocol
(VoIP) network, Internet protocol (IP) network, a cable network, a
passive or active optical network, a 4G, 5G, or higher generation
wireless access network, WIMAX network, UltraWideband network,
personal area network or other wireless access network, a broadcast
satellite network and/or other communications network.
[0032] In at least some embodiments, the base station or access
point 122 may be adapted to include a low-power radio, such as a
low-power MIMO radio 182, having a PSK transmitter, and/or an PSK
receiver and/or an PSK transceiver according to the low-power,
low-complexity radios and related devices disclosed herein.
Likewise, in at least some embodiments, the mobile devices 124 and
vehicle 126 may be adapted to include a low-power radio, such as a
low-power MIMO radio, 183a, 183b, 183c, generally 183, having a PSK
transmitter, and/or an PSK receiver and/or an PSK transceiver
according to the low-power, low-complexity radios and related
devices disclosed herein.
[0033] In various embodiments, the access terminal 112 can include
a digital subscriber line access multiplexer (DSLAM), cable modem
termination system (CMTS), optical line terminal (OLT) and/or other
access terminal. The data terminals 114 can include personal
computers, laptop computers, netbook computers, tablets or other
computing devices along with digital subscriber line (DSL) modems,
data over coax service interface specification (DOCSIS) modems or
other cable modems, a wireless modem such as a 4G, 5G, or higher
generation modem, an optical modem and/or other access devices.
[0034] In various embodiments, the base station or access point 122
can include a 4G, 5G, or higher generation base station, an access
point that operates via an 802.11 standard such as 802.11n,
802.11ac or other wireless access terminal. The mobile devices 124
can include mobile phones, e-readers, tablets, phablets, wireless
modems, and/or other mobile computing devices.
[0035] In various embodiments, the switching device 132 can include
a private branch exchange or central office switch, a media
services gateway, VoIP gateway or other gateway device and/or other
switching device. The telephony devices 134 can include traditional
telephones (with or without a terminal adapter), VoIP telephones
and/or other telephony devices.
[0036] In various embodiments, the media terminal 142 can include a
cable head-end or other TV head-end, a satellite receiver, gateway
or other media terminal 142. The display devices 144 can include
televisions with or without a set top box, personal computers
and/or other display devices.
[0037] In various embodiments, the content sources 175 include
broadcast television and radio sources, video on demand platforms
and streaming video and audio services platforms, one or more
content data networks, data servers, web servers and other content
servers, and/or other sources of media.
[0038] In various embodiments, the communications network 125 can
include wired, optical and/or wireless links and the network
elements 150, 152, 154, 156, etc., can include service switching
points, signal transfer points, service control points, network
gateways, media distribution hubs, servers, firewalls, routers,
edge devices, switches and other network nodes for routing and
controlling communications traffic over wired, optical and wireless
links as part of the Internet and other public networks as well as
one or more private networks, for managing subscriber access, for
billing and network management and for supporting other network
functions.
[0039] FIG. 2A is a block diagram illustrating an example,
non-limiting embodiment of a MIMO communication system 200
functioning within the communication network of FIG. 1 in
accordance with various aspects described herein. According to the
illustrative example, the MIMO communication system 200 includes a
transmitter portion 201 and a nonlinear receiver portion 202. The
transmitter portion 201 includes an M-bit digital beamforming
system 203 in communication with M antennas or radiating elements
204a, 204b, . . . , 204M, generally 204. The receiver portion 202
includes N antennas 205a, 205b, . . . , 205N, generally 205. Each
of the antennas 205 is coupled to a respective radio receiver 206a,
206b, . . . , 206N, generally 206, which are coupled, in turn, to
an N-bit digital receiver processing system 207. Wireless
communication signals propagate between the transmitter portion 201
and the receiver portion 202 via a wireless channel 208.
[0040] The example nonlinear receiver portion 202 uses an RF-in,
bits-out approach that is well-suited for a low-cost, low-power
solution to the scaling problem that arises in massive MIMO. The
receiver portion 202 may include one or more highly efficient
antenna-coupled nonlinear amplifiers and one or more low-power RF
signal processing elements that may include detector elements.
Low-power RF signal processing elements may include, without
limitation, power dividing/summing devices, such as Wilkinson power
dividers, local oscillators operating at low power and/or nonlinear
rectifying elements, e.g., diodes, that facilitate a
direct-to-baseband demodulator, sometimes referred to as an
on-off-keying (OOK) demodulator. The low-powered LO, when applied
to a mixer, is sometimes referred to as a starved mixer. By
combining a received PSK-modulated RF signal with an LO signal
operating at the RF carrier, the PSK signal can be converted to one
or more PAM signals, e.g., I and/or I and Q PAM signals. The
resulting PAM signals are provided to a detector element to obtain
baseband output signals. In at least some embodiments, baseband
signals can be digitized, e.g., using a comparator that may be
configured with a fixed and/or an adjustable threshold upon which
comparisons are determined.
[0041] It is understood that in at least some embodiments baseband
processing may occur prior to digitization. For example, one or
more of gain, filtering and/or attenuation may be applied to one or
more of the baseband signals. Filtering may include passive
filtering and/or active filtering. In a massive MIMO deployment,
the digital outputs of each nonlinear receiver chain may be further
processed in a digital domain to achieve an enhanced, and ideally a
maximum channel capacity. In a full-rank channel, capacity
saturates with the number of transmitters, assuming more receivers
than transmitters, one-bit-per-transmitter as the signal to noise
ratio increases. Consequently, more than one bit-per-channel use
may be achieved as a number of transmitter and receiver chains
increase; this is exemplified by the trivial case of M
single-input-single-output (SISO) channels with one transmitter and
one receiver, which can achieve M bits-per-channel use.
[0042] Although the illustrative examples disclosed herein refer to
envelope detection or OOK, it is understood that other
communication techniques may be used. For example, information may
be impressed upon a transmitted RF according to a different
modulation, such as phase modulations, e.g., PSK and/or
differential PSK (DPSK). In such applications, the receivers
disclosed herein may be adapted as disclosed herein to perform
detection to obtain baseband signals according to the type of
modulation applied to the RF signal. Such applications may use well
established techniques, such as DPSK, energy thresholding or a
combination thereof.
[0043] FIG. 2B is a block diagram illustrating an example,
non-limiting embodiment of a MIMO radio module or cell 210
functioning within the communication network of FIG. 1 and the MIMO
communication system of FIG. 2A in accordance with various aspects
described herein. The example MIMO radio cell 210 includes at least
one antenna 211, an RF signal processing/detection module 215, a
baseband amplifier 216, and an ADC, e.g., a 1-bit ADC 217. In at
least some embodiments, the MIMO cell 210 includes one or more of
an antenna coupler 213 and an RF amplifier 214 (both shown in
phantom). It is understood that some embodiments may not require a
separate antenna coupler 213. Alternatively or in addition, at
least some embodiments may not require an amplifier 214. Depending
on the desired degree of baseband analog processing, some
embodiments may not require the baseband amplifier 216. For
example, a minimal MIMO radio module may include an antenna 211, an
RF signal processing/detection module 215 and a 1-bit ADC, without
necessarily requiring one or more of the antenna coupler 213 or the
RF amplifier 214 and baseband amplifier 216.
[0044] In at least some embodiments, the RF signal
processing/detection module 215 receives an LO signal to facilitate
detection of PSK and DPSK signals. In some embodiments, the MIMO
radio cell 210 includes an LO 209 (shown in phantom) that provides
an LO signal operating at a carrier wave frequency of the received
RF signals. The LO 209 is operated in a low-power configuration,
resulting in a so-called "starved" mixer, in which the LO signal
level biases a nonlinear element such as a diode well below the
threshold voltage/built-in potential, e.g., a diode, of a mixer
and/or a signal detector to which the LO signal may be applied. In
some embodiments, the LO 209 is integral to the RF signal
processing/detection module 215. Alternatively or in addition, the
LO 209 may be separate from the RF signal processing/detection
module 215, but integral to the MIMO radio cell 210. It is
envisioned that in at least some embodiments, a single LO module
209 may supply an LO signal to more than one such RF signal
processing/detection modules 215 and/or to more than one MIMO radio
cells 210. In some embodiments, the LO 209 may be phase locked to
the received RF signal, e.g., using feedback control, such as a
phase locked loop (PLL). Alternatively or in addition, the LO 209
may operate without necessarily being phase locked to the RF
signal, e.g., without an application of feedback control to further
simplify the radio architecture.
[0045] Due to the very large bandwidths available in millimeter
wave spectrum, digital-to-analog converters (DAC) and ADCs must
work at very high sampling rates. Since their power consumption
scales approximately linearly in the sampling rate and
exponentially in the number of bits per sample, only very few data
converters are employed in state-of-the-art systems and a base
station with hundreds of antenna elements may only have a handful
of data converters. Unlike fully analog beamforming systems, where
phase and amplitude can individually be controlled per antenna
element, limiting the number of data converters compromises
robustness and mobility rendering millimeter wave spectrum less
attractive for new use cases such as ultra-reliable low latency
communications (URLLC).
[0046] Such simplified, or minimal complexity MIMO radio cells 210
offer several advantages. For example, a minimally complex module
or cell may occupy a relatively small area of a MIMO receiver
portion 202. Space savings may be advantageous for mobile device
applications, e.g., for a mobile phone, a tablet, a PC, for
appliance applications, such as smart TVs, and/or Internet of
Things (IoT) devices, e.g., home appliances, printers, security
system components, surveillance cameras, residential controllers,
personal assistants, cloud-based voice service appliances, and the
like. In the illustrative example, the dipole antenna 218 has a
maximum dimension determined by its length, L. The example MIMO
radio cell 210 occupies an area defined by the dipole antenna
length L, and a module width, W. In at least some embodiments, the
width W is less than the length L, i.e., W<L, such that an area
occupied by the module is less than a square of the maximum antenna
dimension, i.e., A=L.times.W.ltoreq.L.sup.2.
[0047] Dimensions of an antenna, such as the example dipole antenna
218, which happens to be a bowtie type of dipole antenna adapted to
provide a relatively wide operational bandwidth, may be determined
from an antenna calculator. For example, a length L may be
determined according to: L=0.75.lamda.. Likewise, a width w may be
determined according to w=0.25.lamda.. For example, the MIMO radio
cell 210 configured to operate in the Ka band, having a frequency
between about 26.5-40 GHz, and a corresponding free-space
wavelength between about 11.1 and 7.5 mm. Assuming operation at a
center frequency of about 33 GHz, the free-space wavelength is
about 9.1 mm, may have a length L.apprxeq.6.8 mm and a width
w.apprxeq.2.3 mm. Accordingly, an area occupied by a Ka band MIMO
radio may be less than about 7 mm.times.7 mm.apprxeq.50
mm.sup.2.
[0048] Other advantages of simplified, or minimal complexity MIMO
radio cells 210 include relatively low power requirements and
relatively low thermal load. According to the examples disclosed
herein, the MIMO radio cells 210 use simple energy detectors, such
as envelope detectors, or square law detectors. Such simple
detectors may operate on the received RF signal directly without
requiring any local operator and/or mixing to obtain an
intermediate frequency between RF and baseband, as would be typical
for millimeter wave digital communication systems. Rather the
simple detectors may obtain a baseband signal directly from the RF
signal according to an envelope of the RF signal and/or from a PSK
and/or DPSK type receiver employing a low powered LO in combination
with a nonlinear device providing a mixing of the RF and the LO.
Moreover, the low-resolution, e.g., single-bit, ADC may be operated
in a nonlinear region, e.g., using a simple comparator circuit,
without requiring high-resolution, linear ADCs, as would be typical
for millimeter wave digital communication systems. Still further,
should signal amplification be used, e.g., providing an LNA 214
between the antenna 218 and the RF processing/detection module 215,
the LNA 214 does not need to be operated in a linear region. As the
low-resolution ADC solution relies upon a simple comparator circuit
217, linearity of the received signal does not need to be
preserved. Accordingly, the amplifier, e.g., LNA 214, may be
operated in a nonlinear region, e.g., in saturation. As is true
with operation of the low-power LO 209, it is understood that
operation of an amplifier, e.g., LNA 214, without regard to
preserving linearity, e.g., in saturation, may be accomplished a
substantially less power dissipation that would be required for
linear operation. Likewise, operating the minimal complexity MIMO
radio cell 210 requires relatively low power, certainly much less
than traditional digital communication receivers operating in
comparable wavelengths. Consumption of less power results in
generation of less of a thermal load, e.g., according to component
inefficiencies, power requirements and/or circuital resistive
losses.
[0049] Beneficially, the factors contributing to smaller, simpler
and cooler MIMO receiver modules also reduce initial costs as well
as operational costs, e.g., lower power consumption and cooling.
The reduced module size and reduced thermal load further allows
more MIMO receiver modules to be used in the same space than would
otherwise be possible with traditional MIMO receivers employing
higher-resolution ADCs, and/or LNAs operating in their linear
regions, digital receivers and/or detectors employing traditional
LO-mixer combinations, e.g., not starved, but rather operating in a
linear region. The reduced cost, thermal load and size permit
larger numbers to be used within the same footprint, which is well
adapted for massively MIMO systems. It is envisioned that massively
MIMO systems may employ scores, if not hundreds, or even more MIMO
receiver modules.
[0050] The example MIMO radio cell 210 includes a dipole antenna
218--in this instance, a bowtie antenna 218. It is understood that
in general the antenna 211 may include a balanced structure, such
as a dipole, an unbalanced structure, such as a monopole, and/or a
patch. The antenna may be a resonant structure, such as the example
dipole antenna 218, having a length L that approximates one-half of
an operating wavelength (.lamda.), i.e., L.apprxeq..lamda./2.
Without limitation, the antenna 211 may include an electric-field
sensing element, a magnetic-field sensing element, or a combination
of both an electric-field and a magnetic-field sensing elements. By
way of non-limiting example, it is understood that antenna 211 may
include a wire structure, such as a dipole, a monopole, or a loop.
It is understood that a loop antenna 211 may be configured
according to varying geometries, e.g., a circular loop, an
elliptical loop, a square loop, and a rectangular loop. A wire
structure antenna 211 may be free-standing, e.g., formed from a
rigid conductor and/or formed on a substrate 219 and/or similar
supporting structure. The antenna 211 may be substantially
omnidirectional, such as the example dipole 218 structure.
Alternatively or in addition, the antenna 211 may offer some
directivity.
[0051] It is understood further that the antenna 211 may operate
according to a preferred polarization, such as a linear
polarization, a circular polarization, or more generally, an
elliptical polarization. By way of example, the dipole antenna 218
may be replaced with a crossed dipole, in which two dipole antennas
are positioned in an orthogonal arrangement and coupled to a common
antenna terminal 212 via a phase shifting element, e.g., a
90-degree phase shifter. Still other antenna 211 may include
antenna arrays, such as Yagi antenna arrays, log-periodic
structures, spiral antennas and the like.
[0052] The antenna coupler 213 is positioned between the antenna
terminal 212 and the RF processing/detection module 215. For
embodiments, in which a gain element, such as the example LNA 214
is included, the antenna coupler 213 may be positioned between the
antenna terminal 212 and the LNA 214. In at least some embodiments,
the antennal coupler 213 is positioned at the antenna terminal 212.
The antenna coupler 213 may include a matching network, such as a
conjugate matching network matching a driving point impedance of
the antenna 211 to a characteristic impedance of a transmission
line extending between the antenna coupler 213 and one or more of
the gain element 214 and the RF processing/detection module
215.
[0053] Alternatively or in addition, the antenna coupler 213
includes a balun. The balun is adapted to facilitate a coupling of
a balanced structure, such as the example dipole antenna 218 and an
unbalanced structure, such as an unbalanced transmission line.
Baluns can facilitate operation of a balanced device, such as the
example dipole antenna 218 by promoting a substantially symmetric
current distribution between each half of the dipole antenna 218.
Baluns may include one or more of transmission lines, lumped
elements, e.g., capacitors and/or inductors, including transmission
line elements, e.g., .lamda./4 transmission line segments, and the
like. In at least some embodiments, the balun structure may include
a lossy element, such as a ferrite element and/or RF chokes adapted
to absorb and/or otherwise prevent propagation of unbalanced
currents.
[0054] In at least some embodiments, the MIMO radio cell 210
includes one or more filters. Filters may include, without
limitation, high-pass filters, low-pass filters and band-pass
filters. In at least some embodiments, filters may be analog
filters, e.g., constructed according to lumped resistor and/or
inductor and/or capacitor components. Alternatively or in addition,
analog filters may utilize one or more waveguide segments, such as
waveguide lengths, shorted waveguide stubs and/or open waveguide
stubs positioned at predetermined lengths along a waveguide, and
the like. One or more filters may be provided, for example, at one
or more of the antenna terminal 212, the antenna coupler 213, an
input of the LNA 214, and output of the LNA, an input of the RF
processing/detection module 215 and/or at the output of the RF
processing/detection module 215, and/or the output of a baseband
processing stage, such as the example baseband amplifier 216. In
some embodiments the filters may be high-pass filters adapted to
block DC currents. Alternatively or in addition, the filters may be
low-pass filters adapted to pass baseband currents.
[0055] The RF processing/detection module 215 may include any
device having a non-linear characteristic curve, e.g., a non-linear
current-voltage (I-V) curve. Examples include, without limitation,
a diode, a transistor, e.g., a transistor wired in a diode
configuration. In practical applications, parasitic values of the
detector may be selected to ensure minimal signal degradation
resulting from operation of the detector device at the frequencies
of operation, e.g., at the RF the carrier frequency and/or the
baseband frequency.
[0056] In some embodiments, the MIMO receive cell 210 may include a
baseband amplifier 216 designed to amplify the baseband signal from
the output of an envelope detector of the RF processing/detection
module 215 to a suitable voltage/current/power level as required by
comparator ADC 217. The amplifier 216 may also act as an
impedance-transforming buffer stage between the RF
processing/detection module 215 and comparator 217.
[0057] The comparator may include any suitable device to provide a
stable binary output according to a comparison of an input baseband
signal to a reference value. For example, the reference value may
be a reference voltage. A value of the reference voltage may be
selected to serve as a decision between a binary 1 or a binary 0.
For example, if an expected voltage of a received baseband signal
is expected to be 0 and 10 microvolts, a threshold value may be
selected as 1/2 the maximum value, i.e., about 5 microvolts. In at
least some embodiments, the threshold voltage is determined
according to a minimum signal level, e.g., a system noise floor, in
which a received voltage above a predetermined value above the
noise floor may represent a binary 1. In some embodiments, the
threshold value is fixed. Alternatively or in addition, the
threshold value may be variable, e.g., according to signal
conditions, noise, conditions, a calibration value, and so on.
[0058] As an example, assume a simplified passive embodiment of
receiver MIMO 210 that omits amplifiers 214 and 216. Further assume
that the system is impedance matched and the noise seen at the
comparator is solely due to thermal noise generated in the envelope
detector. It is well-known that thermal noise in passive systems
exhibits a flat spectral power density of -174 dBm/Hz. If the
system bandwidth is 1 GHz, the corresponding noise power is -84
dBm. Suppose that the input power to the system is -50 dBm (for
signal symbol 1) and the aggregate loss from antenna 218, coupler
and/or filter 213, amplifier 214, and RF processing/detection
module 215 is 20 dB. This corresponds to an output power of
approximately -70 dBm at the input comparator 217. Since the SNR is
relatively high (14 dB), one-half the signal voltage at comparator
217 will approximately lie halfway between the noise floor voltage
and signal on-state. From a voltage standpoint, halving the voltage
reduces power by one-fourth, which corresponds to a threshold power
of -76 dBm. Assuming a 50-Ohm input impedance, this corresponds to
a threshold voltage of approximately 35 .mu.V. In the event that
the comparator hardware 217 is unable to detect voltage differences
this low, because of, e.g., built-in hysteresis, it will be of
benefit to instate baseband amplifier 216 to accommodate lower
input power operation. One potential strategy for adjusting the
threshold is feedback based on individual digital outputs, i.e., if
the comparator 217 is outputting all binary 1's, the comparator
threshold may be set too low and should be increased.
[0059] If a pre-amplifier at millimeter-wave is included, then the
link budget would improve significantly due to the square-law
device. That is, if the power incident upon the receive cell is -70
dBm and the millimeter-wave LNA gain is 30 dB, with a diode
responsivity of 10 kV/W this corresponds to a 1 mV baseband output
voltage. Even this is likely too low to pass along to a standard
CMOS threshold detector which would have noise and hysteresis.
Therefore a baseband voltage amplifier with e.g., 10V/V gain might
be used. The baseband amplifier would have high input impedance
(e.g., greater than the diode video resistance over the channel
bandwidth of -1 GHz, as an example). It would also have relatively
low output resistance in order to pass a multi-GHz signal across
the input capacitance of a CMOS threshold detector IC (perhaps 500
ohms output resistance or less).
[0060] FIG. 2C is a block diagram illustrating an example,
non-limiting embodiment of a MIMO radio module 220 functioning
within the communication network of FIG. 1 and the MIMO
communication system of FIG. 2A in accordance with various aspects
described herein. The example MIMO radio module 220 includes four
RF signal processing/detection cells, 222a, 222b, 222c, 222d,
generally 222. It is understood that other numbers of RF signal
processing/detection cells 222 may be used within a MIMO radio
module 220, including numbers greater than and/or less than four.
Such numbers may be selected based on one or more of power
requirements, thermal loading, operating frequency range,
manufacturability, size constraints, cost, complexity, reliability,
and so on. Each of the RF signal processing/detection cells 222 is
coupled to a respective interconnect or terminal 224a, 224b, 224c,
224d, generally 224, via a respective transmission line 223a, 223b,
223c, 223d, generally 223. The terminals 224 may include an
electrical interconnect adapted for repeated connections and
disconnections, e.g., a connector, such as a coaxial connector, a
push-pin connector, and the like. Alternatively or in addition the
terminals 224 may include more permanent electrical interconnects,
such as solder pads.
[0061] According to the illustrative example, a respective digital
signal and/or digital values y1, y2, y3, y4 is available and/or
otherwise accessible at each terminal 224 of the group of terminals
224. The digital signal and/or value y1, y2, y3, y4 may be
equivalent to an output of the comparator 217 (FIG. 2B) of each
cell 222. The digital signals/values y1, y2, y3, y4 are provided to
a digital signal processor (not shown) for combination and/or
digital processing. At least one example digital signal processor
is the N-bit digital receiver processing system 207 (FIG. 2A).
[0062] The RF signal processing/detection cells 222 may be
identical cells, e.g., according to the example MIMO radio cell 210
(FIG. 2B). Alternatively, the RF signal processing/detection cells
222 may differ, e.g., some RF signal processing/detection cells 222
adapted for one portion of an RF spectrum, while other cells 222
are adapted for another portion of the RF spectrum. Alternatively
or in addition, some RF signal processing/detection cells 222 may
be adapted for one polarization, e.g., linear horizontal, while
other RF signal processing/detection cells 222 are adapted for
another polarization, e.g., linear vertical. Some RF signal
processing/detection cells 222 may be adapted to include LNAs 214,
while other RF signal processing/detection cells 222 may not. For
example, those RF signal processing/detection cells 222 without
LNAs 214 may operate in a passive mode when signal conditions
permit, e.g., relative strong received signal levels, relatively
low interference and/or favorable channel conditions. Other RF
signal processing/detection cells 222 with the LNAs 214 may be
selectively engaged and/or otherwise activated according to
unfavorable signal conditions, e.g., relative weak received signal
levels, relatively high interference and/or unfavorable channel
conditions. Such different cells may be arranged on the same MIMO
radio module 220, e.g., interspersed, and/or arranged in
groups.
[0063] It is envisioned that in at least some embodiments, all of
the RF signal processing/detection cells 222 of a particular MIMO
radio cell 210 may be adapted for one type of RF signal modulation,
e.g., OOK and/or PSK and/or DPSK, and the like. It is envisioned
further that in at least some embodiments one or more different
types of MIMO radio cells 210 may be used within a common MIMO
radio application. For example, a MIMO radio may include one or
more MIMO radio cells 210 adapted for OOK modulation and one or
more other MIMO radio cells 210 adapted for PSK modulation.
Alternatively or in addition, a single MIMO radio cells 210 may
include one or more different types of RF signal
processing/detection cell 222, e.g., with at least one RF signal
processing/detection cell 222 adapted for PSK and/or DPSK
modulation, and at least one other RF signal processing/detection
cell adapted for OOK modulation. It can be appreciated that such
mixed mode configurations can offer flexibility in operation and/or
application. As material and/or fabrication costs are anticipated
to be relatively low in view of the simple, low-complexity
architectures, and as dimensions of any realizable modules amenable
to compact systems, such mixed mode constructions may be used
despite there being any immediate need for mixed mode operation.
Namely, a mixed mode device may be deployed, but only operated
according to one of multiple available modes.
[0064] Alternatively or in addition different MIMO radio modules
220 may be combined within a common receiver portion 202 (FIG. 2A).
For example, a first group of MIMO radio modules 220 may include
passive detectors, e.g., without LNAs 214, while a second group of
MIMO radio modules 220 may include active detectors, e.g.,
including LNAs 214. Other parameters, such as antennas, matching
networks and/or filters, when provided, may differ within the same
MIMO radio module 220 and/or according to the different groups of
MIMO radio modules.
[0065] In at least some embodiments, one or more of the cells 222
may include an active element, such as an LNA 214, and/or an LO 209
and/or a comparator 217 (FIG. 2B). In such instances, each of the
cells 222 may require electrical power, e.g., according to one or
more voltage levels. It is envisioned that in at least some
embodiments, the electrical power, e.g., the one or more voltage
levels may be provided by one or more power supplies 225 provided
at the MIMO radio module 220. Alternatively or in addition, one or
more voltage levels may be provided by a separate power source,
such as a stand-alone power supply. In such configurations, the
MIMO radio module 220 may include a power interconnect, e.g., a
connector, adapted to interconnect to a remote power source.
Conductors, e.g., traces, may be provided from contacts of a power
connector to each of the cells 222. In at least some embodiments, a
single LO 227 may supply an LO signal to one or more of the cells
222, as illustrated. It is understood that in at least some
embodiments, the LO may be integral to the MIMO cell 220. In such
instances, the LO may also obtain power from the power supply 225.
Alternatively or in addition, the LO may be supplied separately
from the MIMO cell 220.
[0066] According to the illustrative example, the MIMO radio cells
222, including antennas 211 (FIG. 2B), are spaced according to a
center-to-center distance d. Depending upon a size and/or shape of
the cells, there may be a separate distance between adjacent cells,
as shown. However, it is envisioned that in at least some
embodiments, the cells 222 may be adjacent to each other, such that
there is no separation between adjacent cells 222. The cell spacing
d may be uniform between all cells 222 of the module 220.
Alternatively the cell spacing d may vary between at least some of
the cells 222.
[0067] According to the illustrative example module, the cells 222
are arranged in a one-dimensional fashion, e.g., along a common
linear axis 226. In some embodiments, the cells may be arranged in
a two-dimensional fashion, e.g., according to a 2-dimensional (2D)
pattern. The 2D pattern may be a regular pattern, in which spacings
between adjacent cells 222 is uniform, e.g., constant in one or two
dimensions. Example 2D patters include, without limitation, a
rectangular grid, a hexagonal close pack grid, and the like. Such
3D patterns are beneficial at least in that they permit a greater
number of cells 222 to be provided within a relatively compact
receiver portion 202. It is envisioned that in at least some
embodiments, the cells 222 may be arranged in a three-dimensional
(3D) fashion, e.g., according to a conformal pattern that may
conform to a 3D surface, such as a cube, a tetrahedron, a
parallelepiped, a cone, or a curved surface, such as a spherical
portion and/or an ellipsoidal portion.
[0068] FIG. 2D is planar view of an example, non-limiting
embodiment of an RF front end for a MIMO radio module 230, in this
instance, a low-power, PSK and/or DPSK receiver, functioning within
the communication network 100 of FIG. 1 and the MIMO communication
system 200 of FIG. 2A in accordance with various aspects described
herein. It is understood that in some applications, the MIMO radio
module 230 may include an OOK receiver and/or a combination of
different types of receivers that may be interconnected to a common
and/or different antennas. The example MIMO radio module 230
includes a substrate 231 upon which the antenna cells and baseband
distribution network are formed. The illustrative radio module 230
includes four radio cells 232, four connectors 234 and a baseband
distribution network 233. Each radio cell 232 is in communication
with a respective one of the connectors 234 via the RF distribution
network 233. In operation, each radio cell 232 receives a wireless
MIMO signal, detects bandpass information modulated onto the
wireless MIMO signal at a remote MIMO transmitter, e.g., using OOK,
PSK and/or DPSK modulation, and generates a detected baseband
signal representative of the modulated RF signal. The analog signal
is passed to a signal combiner, which then passes to an ADC, e.g.,
a comparator, then in at least some embodiments to a digital
processing unit (not shown) to determine an estimate of the
transmitted information originating at the MIMO transmitter. This
present example embodiment may be considered a limited
implementation of the MIMO receiver 210 (FIG. 2B), comprising an
antenna 236, an antenna coupling/matching network 237 at antenna
terminal, an RF LNA, an RF signal processing/detection module and
an envelope detector.
[0069] A first inset illustrates in more detail one of the MIMO
radio cells 232'. The example MIMO radio cell 232 includes a bowtie
dipole antenna 236, an antenna coupler 237, an RF signal
processing/detection circuit 238, a first stub tuner 239 and a
second stub tuner 240. The RF signal processing/detection circuit
238 is in electrical communication with the dipole antenna via the
coupler 237. A more detailed illustration of the example antenna
coupler is provided in a second inset 237'. The antenna coupler
237' includes a capacitive arrangement adapted to block a transfer
of low frequencies, e.g., DC, between the dipole antenna 236 and
the RF signal processing/detection circuit 238. The example
capacitive coupler 237' includes an inter-digitated structure
extending in length to about 100 m, with each digit of the
inter-digitated structure having a width of about 10 m, and a
separation from adjacent digits of about 2 .mu.m. The antenna
coupler configuration 237' ensures that received RF signals at the
approximate operating frequencies, e.g., K-band, are passed from
the antenna 236 to the RF signal processing/detection circuit 238
with minimal attenuation and/or distortion.
[0070] The RF signal processing/detection circuit 238 receives an
RF signal responsive to exposure of the dipole antenna 236 to a
wireless MIMO signal. Thus, the RF signal will depend upon the
transmitted MIMO signal as adapted by a wireless RF channel between
the remote transmitter and the dipole antenna 236. To at least some
extent, the RF signal will depend on a position and/or orientation
of the dipole antenna 236. Accordingly, it is expected that in at
least some applications, RF signals obtained by the different MIMO
radio cells 232 when exposed to the same wireless RF signal may
differ according to channel variances. The diode is configured to
rectify the received RF signal to obtain a representation of an
amplitude or envelope of the received RF signal. The stub tuners
239 and/or 240 may facilitate impedance matching of the RF signal
processing/detection circuit 238 to a transmission line and/or to
other circuit elements, such as the low-resolution ADC or
comparator (not shown). According to the illustrated example, the
first stub tuner 239 presents an open circuit at a terminal of the
RF signal processing/detection circuit 238, at the RF frequency,
which aids in impedance matching at the RF frequency from the
antenna 236 to the RF signal processing/detection circuit 238. The
second stub tuner 240 presents a reactive impedance to twice the RF
frequency at a terminal of RF signal processing/detection circuit
238, which prevents leakage of the second harmonic into the
baseband distribution network 233.
[0071] The length of the example dipole antenna 236 is about 4 mm.
It is worth noting that the dimensions of the MIMO radio cell 232'
is about 4 mm by about 4.5 mm. Namely, the dimensions of the cell
232' are substantially determined according to a size of the
antenna 236 resulting in an extremely compact form factor well
adapted for positioning proximate to other such cells 232 in the
example MIMO radio module 230.
[0072] The substrate 231 may include any suitable substrate that
supports conductive elements, such as radiating elements, i.e.,
antennas, transmission lines, and the like. Examples include,
without limitation, dielectric substrates including one or more of
glass, fiberglass, plastics, polymers, and/or semiconductors, e.g.,
silicon. Further example substrates include bakelite or
polyoxybenzylmethylenglycolanhydride, commonly used as an
electrical insulator possessing considerable mechanical strength.
Other alternatives include glass-reinforced epoxy laminate sheets,
tubes, rods and printed circuit boards (PCB), such as FR-4. Still
other alternatives include glass reinforced hydrocarbon/ceramic
laminates materials, such as RO4003.RTM. Series High Frequency
Circuit Materials, PTFE laminates and glass microfiber reinforced
PTFE (polytetrafluoroethylene) composite materials, e.g.,
RT/Duroid.RTM. laminates, produced by Rogers Corporation.
[0073] The conductive elements, such as the antennas, matching
networks, filters and/or the RF distribution networks may be
configured upon the substrate 231. Such conductive elements may be
defined by PCB fabrication processes including without limitation
one or more of chemical etching, chemical deposition, semiconductor
fabrication processes, or combination of both PCB and semiconductor
fabrication processes. PCB fabrication processes include, without
limitation imaging desired layout on conductor, e.g., copper, clad
laminates, etching or removing excess copper from surface and/or
inner layers to define and/or otherwise reveal traces and/or device
mounting pads, creating a PCB layer stack-up by laminating, e.g.,
heating and pressing, board materials at high temperatures, and the
like. PCB fabrication processes may include drilling holes for
mounting holes, through hole pins and vias. Semiconductor
fabrication processes may include one or more of a deposition that
grows, coats, or otherwise transfers a material onto a substrate,
e.g., a semiconductor wafer. Available technologies include,
without limitation, physical vapor deposition, chemical vapor
deposition, electrochemical deposition, molecular beam epitaxy and
atomic layer deposition among others.
[0074] Low-resolution, receivers with a 1-bit ADCs can be optimal
in a bits/Joule-sense if the RF front-end is sufficiently
low-power. The inherent nonlinearity of a 1-bit ADC permits the
radio to be designed to satisfy power constraints without regard
for linearity. As disclosed herein the RF front-end may be
extremely low-power (even passive).
[0075] The example energy detector is configured to operate at
about 38 GHz. The energy detector may incorporate a W-band
zero-bias diode (ZBD), available from Virginia Diodes, in a 50-ohm
co-planar waveguide (CPW) environment with 150 .mu.m pitch pads.
The CPW metal is 20 nm Ti, 480 nm Au deposited by an electron-beam
evaporation liftoff process on 500-.mu.m-thick high-resistivity
(.rho.>5 k .OMEGA.cm) silicon. A single-stub network matches the
input to the ZBD, while two stubs at the output provide
terminations at fc (open) and 2fc (reactive). The diode is
flip-chip soldered to the pads by hotplate using low-melting-point
indium alloy solder balls. Gold wirebonds (diameter 25 .mu.m) are
used to equalize ground plane potential in the CPW, especially at
stub junctions.
[0076] FIG. 2E is a block diagram illustrating an example,
non-limiting embodiment of a radio system 245 including an antenna
array functioning within the communication network of FIG. 1 and
the MIMO communication system of FIG. 2A. The radio system 245
includes a digital baseband subsystem 250 in communication with one
or more of a transmitter subsystem 246 and a receiver subsystem
247. The transmitter subsystem 246 includes multiple up-converter
modules 254a, 254b . . . 254n, generally 254. Each of the
up-converter modules 254 is in communication with a respective
transmit antenna 248a, 248b . . . 248n, generally 248. In at least
some embodiments, the transmitter subsystem 246 includes one or
more transmit beam forming modules 260a, 260b . . . 260n, generally
260 (shown in phantom). Each of the beamforming modules 260 may be
communicatively coupled between respective ones of the up-converter
modules 254 and the transmit antennas 248.
[0077] In operation, the transmit beamforming modules 260 may apply
one or more of a gain or a phase offset to transmit signals
received from the up-converter modules 254. The gain and/or phase
adjusted transmit signals may then be routed to the antennas 248
for wireless transmission to remote terminals. The transmit
antennas 248 may function as transducers, e.g., converting currents
and/or voltages of the gain and/or phase-adjusted transmit signals
into electromagnetic waves. It is conceivable that the antennas 248
may include any antenna elements suitable for operation in any
intended operational frequency range or band. According to the
illustrative embodiments and without limitation, the transmit
antennas 248 may operate in the millimeter wave spectrum.
Accordingly, such elements may include dipole antennas, monopole
antennas, loop antennas, patch antennas, aperture antennas, e.g.,
horn antennas and/or slot antennas, and the like.
[0078] The transmit antennas 248 generally include respective
performance parameters, such as radiation patterns, polarizations,
input impedances, radiation efficiencies and the like. It is
understood that groupings of multiple antenna elements, such as the
example antennas 248, may be arranged according to a particular
arrangement, generally referred to as an antenna array. It is
further understood antenna arrays may include performance
parameters, such as array patterns, e.g., beamwidth, power gain,
directivity, azimuth and/or elevation angles, aperture size, nulls,
steerability, and so on. It is further understood that antenna
array performance may be determined according to one or more of a
type or types of antenna element(s) used, alignment and/or
orientation(s) of the antenna elements, e.g., linear, rectangular,
conformal, spacing between adjacent antenna elements, e.g.,
uniform, non-uniform, and so on.
[0079] In at least some embodiments, such antenna array performance
parameters may be further established, adjusted and/or otherwise
controlled according to one or more of gain or phase differences
across the antenna elements of the array. In at least some
embodiments, the transmit beam forming modules 260 may apply a
fixed gain offset across transmit antenna elements 248 of the
antenna array. Alternatively or in addition, the beam forming
modules 260 may apply an adjustable gain offset. The gain offset
may include one or more of gain, e.g., amplification and/or
attenuation. Likewise, in at least some embodiments, the transmit
beam forming modules 260 may apply a fixed phase offset across
transmit antenna elements 248 of the antenna array. Alternatively
or in addition, the transmit beam forming modules 260 may apply an
adjustable phase offset.
[0080] To the extent that one or more of the gain and/or phase of
the beam forming modules 260 may be adjustable, one or more of the
beam forming modules 260 may receive a control signal (shown in
phantom). The control signal is adapted to adjust one or more of
any adjustable gain, attenuation and/or phase elements of the beam
forming modules 260. For example, control signals may be provided
by a MIMO controller, such that the antenna elements 248 and/or
antenna array may provide mobile service to mobile subscriber units
according to a mobile communications protocol, such as the example
protocols disclosed herein.
[0081] Although the example radio system 245 shows one up-converter
module 254 in communication with a single transmit antenna 248, it
is understood that in at least some embodiments, one or more of the
up-converter modules 254 may be in communication with more than one
transmit antennas 248. For example, an antenna subarray of two or
more transmit antenna elements 248 may receive a transmit signal
from a single up-convert module 254 for transmission by the
subarray of transmit antenna elements 248. Alternatively or in
addition, it is conceivable that more than one up-converter
elements may be in communication with a single antenna element.
Accordingly, a single transmit antenna element 248 may wirelessly
transmit signals from more than one of the up-converter modules
254. For completeness, it is further conceivable that more than one
up-converter modules 254 may be in communication with a common
subgroup of transmit antenna elements 248, such that the subgroup
of transmit antenna elements 248 may wirelessly transmit signals
from the group of up-converter modules. For example, a single
antenna array made up of sub-arrays may engage in simultaneous
communications with more than one wireless terminals in one or more
different locations.
[0082] The example transmitter subsystem 246 receives digital
baseband signals from the digital baseband module 250. The digital
signals may be converted to analog signals before upconverted and
wirelessly transmitted via one or more of the antennas 248.
According to the illustrative embodiment, each upconverter module
254 receives an analog signal from a respective digital-to-analog
converter (DAC) 252a, 252b . . . 252n, generally 252. The digital
signal may contain information to be wirelessly transmitted by the
transmit antennas 248 according to a particular wireless
communication protocol, such as the example protocols disclosed
herein or otherwise generally known to those skilled in the art.
Accordingly, the digital signal may include signaling information
that may be used for one or more of establishing wireless
communications with a remote wireless terminal, managing mobility
to facilitate delivery of wireless services to mobile terminals,
and the like. Alternatively or in addition, the digital signal may
include user data. Without limitation, user data may include voice,
e.g., VoIP, audio streaming, video streaming, text messaging,
email, Web browsing, delivery of HTML pages, and the like.
[0083] The receiver subsystem 247 includes multiple down-converter
modules 253a, 253b . . . 253n, generally 253. Each of the
down-converter modules 253 is in communication with a respective
receive antenna 249a, 249b . . . 249n, generally 249. In at least
some embodiments, the receiver subsystem 247 includes one or more
receive beam forming modules 259a, 259b . . . 259n, generally 259
(shown in phantom). Each of the receive beamforming modules 259 may
be communicatively coupled between respective ones of the
down-converter modules 253 and the receive antennas 249. It is
understood that configurations and/or operation of the receiver
subsystem 247 may be similar to that described above in reference
to the transmitter subsystem 246, distinguishable in that the
receive antennas 249 receive wireless signals in the form of
electromagnetic waves and convert the received wireless signals
into received current and/or voltage signals suitable for
processing by the down-converter module 253, and the like.
[0084] The individual antennas 249 may include any of the
aforementioned types of transmit antennas 249. In at least some
embodiments, the transmit antenna elements 248 and the receive
antenna elements 249 are the same types of antenna elements.
Alternatively or in addition, at least some of the receive antenna
elements 249 may differ from the transmit antenna elements 248,
e.g., according to differences in polarization, frequency, gain
and/or directivity requirements, and so on. As with the transmit
antennas 248, receive antenna array performance parameters may be
further established, adjusted and/or otherwise controlled according
to one or more of gain or phase differences across the antenna
elements of the array. In at least some embodiments, the receiver
subsystem 247 includes one or more receive beam-forming modules
259a, 259b . . . . 259n, generally 259. The receive beam forming
modules 259 may apply a fixed gain offset across receive antenna
elements 249 of the antenna array. Alternatively or in addition,
the receive beam forming modules 259 may apply an adjustable gain
offset. The gain offset may include one or more of gain, e.g.,
amplification and/or attenuation. Likewise, in at least some
embodiments, the receive beam forming modules 259 may apply a fixed
phase offset across receive antenna elements 249 of the antenna
array. Alternatively or in addition, the receive beam forming
modules 259 may apply an adjustable phase offset.
[0085] The example receiver subsystem 247 provides digital baseband
signals to the digital baseband module 250. Received analog signals
obtained from received wireless signals may be converted to digital
signals before down converted. According to the illustrative
embodiment, each downconverter module 254 receives an analog signal
from a respective receive antenna element 249 and provides a
corresponding down-converted and/or detected signal to a respective
one of a number of analog-to-digital converters (ADC) 251a, 251b .
. . 251n, generally 251. The received analog signal may contain
information received by the receive antennas 249 according to a
particular wireless communication protocol, such as the example
protocols disclosed herein or otherwise generally known to those
skilled in the art. Accordingly, the received, converted digital
signal may include signaling information that may be used for one
or more of establishing wireless communications with a remote
wireless terminal, managing mobility to facilitate delivery of
wireless services to mobile terminals, and the like. Alternatively
or in addition, the digital signal may include user data. Without
limitation, user data may include voice, e.g., VoIP, audio
streaming, video streaming, text messaging, email, Web browsing,
delivery of HTML pages, and the like.
[0086] It is understood that operation of complex communication
systems, such as the example radio system 245, may require precise
timing across large numbers of components. For example, antenna
arrays including multiple antenna elements 248, 249 may require
precise control of one or more of frequency, phase, or time across
the transmit antenna elements 248 and/or the receive antenna
elements 249. Such precision may be necessary to ensure proper
operation of the radio system 245, e.g., according to any
applicable communication protocol. For example, phase coherence may
be necessary to ensure proper operation of an antenna array, e.g.,
supporting the array's gain, and/or directivity, and/or beamwidth,
and/or null-steering and the like. Alternatively or in addition,
ensuring frequency and/or phase synchronization, e.g., coherence,
according to a predetermined threshold may be necessary to ensure
one or more of modulation, demodulation, data synchronization, and
so on. To this end, the example radio system includes certain
components and/or subsystems adapted to facilitate control of one
or more of frequency, phase, or time across the transmit antenna
elements 248 and/or the receive antenna elements 249, at least to
within a predetermined value, e.g., a threshold value.
[0087] According to the illustrative example, each of the
upconverter modules 254 may include a respective synchronization
module 256a, 256b . . . 256n, generally 256, e.g., including an
adjustable LO. According to the example techniques disclosed
herein, one or more of a phase and/or a frequency of the adjustable
LO may be maintained to within a predetermined accuracy with the
adjustable LOs of one or more other synchronization modules 256.
Likewise, each of the down-converter module 253 may include a
respective synchronization module 255a, 255b . . . 255n, generally
255, e.g., including an adjustable LO. According to the example
techniques disclosed herein, one or more of a phase and/or a
frequency of the adjustable LO may be maintained to within a
predetermined accuracy with the adjustable LOs of one or more other
synchronization modules 255. In at least some embodiments, one or
more of the synchronization modules 256 of the transmitter
subsystem 246 may be synchronized, e.g., coherent, with one or more
of the synchronization modules 255 of the receiver module 247.
[0088] It can be appreciated that establishing and/or maintaining
such synchronization, which may include phase coherence, is a
difficult challenge, particularly at higher frequencies, such as
the example millimeter wave band and for large numbers of up and
down-converter modules 254, 253 and large numbers of antenna
elements 248, 249. In particular, massive MIMO arrays may include
hundreds, or perhaps even thousands or tens of thousands of such up
and down down-converter modules 254, 253 and/or antenna elements
248, 249. One such solution would be to provide a common LO, which
would be distributed to each of the up and down-converter modules
254, 253. To the extent that an RF signal of the common LO is
divided among the different synchronization modules 255, 256, a
substantial power would be required. Consider an example power
requirement of about 0 dBm LO level at each the synchronization
modules 255, 256. A modest massive MIMO system with 1,000 elements
would then require a master LO power level of at least 30 dBm,
before power division. Considering signal loss and inefficiencies
of any realizable system, a stable millimeter wave source providing
more than 1 Watt at operational frequencies would be required. Such
challenges would be complex and costly, at the very least, if not
altogether impossible for at least some configurations.
[0089] Another approach would be to include multiple LOs phase
locked to a master LO. Some combination of power division and
duplication could be applied. Consider 10 LOs, each supporting 100
synchronization modules 255, 256 of the example 1,000 element
massive MIMO system. Such duplication of LOs would reduce power
requirements, e.g., with each LO operating at 20 dBm. However,
there remains a challenge of establishing and maintaining
synchronization, e.g., phase coherence, of the example ten LOs.
Even if it were possible to maintain phase coherence of the ten
LOs, a 0.1 mW requirement may be costly and complex at millimeter
wave frequencies.
[0090] The illustrative embodiment provides an adjustable LO at
each of the synchronization modules 255, 256. The radio system 245
also includes a common timing reference 257 and a timing
distribution network 258. The timing distribution network 258 is
communicatively coupled between the timing reference 257 and one or
more of the synchronization modules 255, 256. According to the
illustrative example, the timing reference 257 may a pulse
generator adapted to generate one or more timing pulses. In at
least some embodiments, the timing reference 257 includes a master
LO, from which the timing pulses may be synchronized.
[0091] In some embodiments, a timing pulse may be provided at a
pulse width and/or pulse repetition frequency that is substantially
lower than an operational frequency of the master LO. For example,
the timing pulse may be one or more orders of magnitude lower than
an operational frequency of the master LO. Consider an example
system in which the master LO operates at 1 GHz. The timing pulse
may be generated according to about 10 MHz, i.e., 100 times lower
frequency. In at least some embodiments, the timing distribution
network receives one or more timing pulses from the timing
reference 257 and distributes the timing pulses to one or more of
the synchronization modules 255, 256. According to the illustrative
embodiment, the timing distribution network 258 is in communication
with each of the synchronization modules 255, 256, providing a
timing reference to one or more of the synchronization modules 255,
256 as necessary.
[0092] In some embodiments, some, conceivably all of the
synchronization modules 255, 256 receive a timing pulse from the
timing reference by way of the timing distribution network 258. For
example, each synchronization modules 255, 256 may receive the same
timing pulse, such that the synchronization modules 255, 256 may
adjust their respective adjustable LOs to achieve synchronization,
e.g., coherence. Alternatively or in addition, at least some of the
synchronization modules 255, 256 may receive one timing pulse while
at least one other of the synchronization modules 255, 256 receives
a different timing pulse, both pulses of this example originating
from the timing reference 257 and distributed accordingly by the
timing distribution network 258. In at least some embodiments, many
and perhaps all of the synchronization modules 255, 256 receive a
respective pulse from the timing reference via the timing
distribution network 258. In any instance, the synchronization
modules 255, 256 use their respective timing pulses to achieve
synchronization, e.g., coherence, with other synchronization
modules 255, 256 of the radio system 245.
[0093] It is worth noting that although the transmitter subsystem
246 is illustrated as being coupled to a first group of antennas
248 and the receiver subsystem 247 is illustrated as being coupled
to a second group of antennas 248, it is understood that in at
least some embodiments, the receiver and transmitter subsystems
246, 247 may share a common group of antennas. For example, a
single antenna array, e.g., the first group of antennas 248 may be
used for both transmission and reception of wireless signals
according to the applicable protocol. Alternatively or in addition,
although separate transmitter and receiver subsystems 246, 247 are
illustrated, it is understood that in at least some embodiments, a
common transceiver module may perform both of the transmit and
receive operations. Accordingly, a single adjustable LO may suffice
for both up-converter and down-converter operation within a single
transceiver module, thereby substantially reducing the number of
required adjustable LOs, e.g., by a factor of two.
[0094] FIG. 2F is a block diagram illustrating an example,
non-limiting embodiment of a distributed, synchronized, e.g.,
coherent, LO system 265 functioning with the communication network
of FIG. 1, the MIMO communication system of FIG. 2A, and the radio
system of FIG. 2E in accordance with various aspects described
herein. The synchronized LO system 265 includes a common timing
reference 266, a timing pulse generator 267 and a timing
distribution network 268. The synchronized LO system 265 further
includes multiple adjustable LOs 269a, 269b . . . 269n, generally
269.
[0095] According to the illustrative example, a master LO of the
common timing reference 266 feeds into a pulse generation system of
the timing pulse generator 267, which generates regular pulses
based on an operational frequency of the master LO of the common
timing reference 266. The regular pulses, in turn, are fed from the
timing pulse generator 267 to the timing distribution network 268,
which distributes the regular pulses to one or more of the
adjustable LOs 269. The timing pulses may include RF signals that
may be distributed between one or more of the timing distribution
network 268 and the adjustable LOs 269 using suitable transmission
lines. Alternatively or in addition, the timing pulses may include
digital signals that ma be distributed using transmission lines
and/or wiring or cabling and/or printed circuit board traces, flex
lines, and the like. Transmission lines may include, without
limitation, any of the example transmission lines disclosed herein
or otherwise known to those skilled in the art, including without
limitation, coaxial cable, unshielded twisted pair, shielded
twisted pair, strip line, microstrip, waveguide, fiberoptic cables,
and the like.
[0096] The timing distribution network 268 may include one or more
of a power divider and/or power combiner, such as a Wilkinson power
divider/combiner. Alternatively or in addition, the timing
distribution network may include nodes, such as interconnections of
wires and/or PCB traces. Still other signal splitters and/or
combiners may include RF couplers, such as hybrid couplers adapted
to combine and/or split power between coupler ports according to a
prescribed phase offset, e.g., .+-.90.degree. and/or
.+-.180.degree. and so on.
[0097] Alternatively or in addition, the riming distribution
network 268 may include one or more switches. The switches may
operable according to a switch control signal to direct timing
pulses according to a predetermined routing schedule. By way of
nonlimiting example, the switches may include single pole, single
throw (SPST) type switches that connect and/or disconnect the pulse
generator 267 to one or more selective ones of the correctable LOs
269. Other types of switches may include single pole, double throw
(SPDT) type switches that selectively connect the pulse generator
267 to one of two switched correctable LOs 269. In at least some
embodiments, the timing distribution network 268 includes a switch
matrix configured to switch a single timing pulse and/or single
timing pulse train of a group of timing pulses to one or more of
the correctable LOs 269. The switches and/or switch matrix may
include mechanical switches, e.g., servo controlled. Alternatively
or in addition, the switches and/or switch matrix may include
semiconductor switches, e.g., transistor switches.
[0098] The switches may actuate, i.e., switch, according to a
switching control signal. The switching control signal may be
received from a separate controller, not shown, such as a MIMO
antenna controller. Alternatively or in addition, the switching
control signal may be received from a radio module timing
distribution controller. For example, the radio module timing
distribution controller provides a switching control signal that
selectively connects one or more of the correctable LOs 269 to the
timing pulse generator 267. The switching control signal may be
adapted to switch control in a systematic and repeatable manner,
e.g., each correctable LO 269 of a group of correctable LOs 269
receiving a timing pulse within a timing pulse window, while other
correctable LOs 269 do not receive any timing pulse during the same
timing pulse window. Different correctable LOs 269 may receive
respective timing pulses during respectively different timing pulse
windows. Different timing pulse windows may be allocated to
different correctable LOs 269 or groups of correctable LOs 269,
with a refresh rate, such that synchronization may be
maintained.
[0099] It is conceivable that in at least some embodiments, one or
more of the timing pulse window size and/or number of timing pulse
windows between a repeated of the timing pulse windows may depend
upon one or more of a frequency of operation, a type of modulation
applied to RF signals processed according to the corrected LOs 269,
applicable wireless protocol, observable error rates, temperature,
RF propagation characteristics, e.g., quality of service (QoS),
channel parameters, class of service, type of service, and the
like.
[0100] In at least some embodiments, the LO system 265 includes one
or more frequency multipliers 270a, 270b . . . 270n, generally 270.
For example, a corrected LO 269 provides a sable, synchronized,
e.g., coherent, output at a first frequency, say 8 GHz, yet the
required frequency of operation is about 32 GHz. In such instances,
an output of the corrected LO 269 is provided to the multiplier
270, which may include a nonlinear element adapted to provide an
output signal obtaining harmonics of the applied input signal.
According to the illustrative example, a fourth harmonic of the 8
GHz signal would provide a stable, synchronized signal at the
operating frequency of 32 GHz. It is understood that a frequency
multiplier 270 may include filters and/or other signal conditioning
elements adapted to attenuate and/or otherwise remove unwanted
signal components, e.g., at frequencies outside of an intended
operational frequency range, while passing those signals within the
intended operational frequency range.
[0101] FIG. 2G depicts a graphical representation of LO
synchronization signals 285 according LO correction system
functioning with the communication network of FIG. 1, the MIMO
communication system of FIG. 2A, the radio system of FIG. 2E, and
the distributed, coherent LO system of FIG. 2F in accordance with
various aspects described herein. A portion of a corrected LO
output 286 of an adjustable LO, e.g., of the correctable LO 269
(FIG. 2F) and/or the adjustable LO of the synchronization modules
255, 256 (FIG. 2E). The example corrected LO output 286 is a
sinusoid having a frequency f.sub.LO and a period of 1/f.sub.LO. It
is understood that the adjustable LO producing the corrected LO
output 286 may be controlled to vary the corrected LO frequency.
Namely if an LO frequency f.sub.LO' is not synchronized to some
reference, e.g., the timing pulse and/or the master oscillator,
then a control signal is applied to the adjustable LO to vary the
operational frequency in a manner adapted to correct the error.
That is, if the LO frequency is too high, i.e.,
f.sub.LO'>f.sub.LO_Target, then the adjustable LO is adjusted to
reduce the frequency. The control signal may be obtained from an
error signal determined according to a difference between the
adjusted LO output and the target and/or synchronized frequency.
The control signal may be applied to the adjustable LO in a
feedback loop, e.g., as in a phase lock loop (PLL).
[0102] The graphical representation of LO synchronization signals
285 includes further detail regarding generation of the timing
pulses. By way of illustrative example, the pulse generator 267
(FIG. 2F) provides a pulse signal 287. In at least some
embodiments, the pulse signal 287 is a periodic signal repeating
with a clock period t.sub.clk. The pulse signal 287 may obtained as
a substantially square wave, e.g., a digital signal. Alternatively
or in addition, the pulse signal may take on other wave shapes,
such as sinusoids, offset sinusoids, and the like. The pulse signal
may have a duty cycle that describes a variation between a "high"
value of the pulse and a "low" value of the pulse. According to the
illustrative example, and without limitation, the high value has a
pulse width of p, and a duty cycle of about 50%. Successive pulse
cycles occur at respective times, e.g., a first reference pulse at
t.sub.1, a second pulse at t.sub.2 and an nth pulse at t.sub.n. In
at least some embodiments, the individual pulse times may be
relative to an arbitrary time period, e.g., according to a pulse
identified as a reference pulse.
[0103] In some embodiments one or more switched pulses 288a, 288b .
. . 288n, generally 288, are obtained. A first switched pulse 288a
provides a "high" pulse portion beginning at a reference pulse time
t.sub.1 and lasting for a pulse period of p. The first switched
pulse 288a may be provided to a first selective one of the
adjustable LO, e.g., of the correctable LO 269 (FIG. 2F) and/or a
first selective one of the adjustable LO of the synchronization
modules 255, 256 (FIG. 2E). The switched pulse signal may remain in
a "low" state until another pulse having a "high" state is received
at a later time. According to the illustrative example, a time
period between successive "high" portions or pulses of the first
switched pulse 288a, is a pulse repetition time T. In this manner,
a single pulse having pulse width p is provided by the first
switched pulse 288a every T seconds. In at least some embodiments,
the pulse, e.g., a rising and/or falling edge of the pulse, and/or
the time between successive pulses, may be used to detect a
difference between the operational frequency of the adjustable LO
and a reference synchronization source, such as the master
oscillator, to ensure synchronization within the radio system
245.
[0104] Continuing with the illustrative example, a second switched
pulse 288b provides a "high" pulse portion beginning at a reference
pulse time t.sub.2 and lasting for a pulse period of p. The second
switched pulse 288b may be provided to a second selective one of
the adjustable LO, e.g., of the correctable LO 269 (FIG. 2F) and/or
a second selective one of the adjustable LO of the synchronization
modules 255, 256 (FIG. 2E). In this example, the second switched
pulse occurs at a time t.sub.2, and remains "high" for a period p,
repeating according to a pulse repetition rate, e.g., the same time
period T as in the aforementioned first switched pulse 288c.
Additional switched pulses 288 may continue in a like manner, each
one being offset from at least some of the others by one or more
clock periods t.sub.clk. Here, N pulses are provided before any of
the pulses repeat.
[0105] It is important to appreciate that the pulses do not
overlap. Thus, power handling concerns of power splitting a pulse
may be avoided, by providing full power pulses to one or more
individual and/or subgroups of the adjustable LOs. For example, a
pulse repetition rate T may be selected, determined or otherwise
calculated as a maximum period by which the adjustable LO frequency
may drift before requiring an adjustment to maintain a desired
level of synchronization, e.g., coherence. Similarly, the pulse
widths p, may be determined according to a number N of switched
timing pulses required to serve the adjustable LOs.
[0106] Consider an example in which 1000 adjustable LOs are service
by a single timing pulse generator 267, and that pulse repetition
rate can be no more than about 1 sec for ant one adjustable LO.
Accordingly, the pulse repetition rate T-1 sec, and the pulse width
p=0.5 msec as the pulse repetition period is divided 1000 times,
with one pulse for each adjustable LO, and assuming a 50% duty
cycle. If greater numbers of adjustable LOs are used that might
otherwise be serviced by a single timing pulse generator and
switching configuration, it is understood that a combination of
pulse signal division and/or switching may be applied.
[0107] Consider another example in which 1000 presents a maximum
practical limit of adjustable LOs that may be serviced by the
switching network. In this example, the reference timing pulse
trains may be divided into two coherent reference timing pulse
trains. Each pulse train may be distributed according to a
respective switching network adapted to provide pulses to 1000
elements, such that the combined approach permits the 2000 elements
to be operated in a synchronized, e.g., coherent, manner.
[0108] FIG. 2H is a block diagram illustrating an example,
non-limiting embodiment of a corrected LO 275 functioning with the
communication network of FIG. 1, the MIMO communication system of
FIG. 2A, the radio system of FIG. 2E, and the distributed, coherent
LO system of FIG. 2F in accordance with various aspects described
herein. The example corrected LO system 275 includes a counter 276,
an error detector 278, a loop filter 279 and an adjustable LO
277.
[0109] In more detail, the corrected LO 275 includes a first port
280' or input terminal in communication with a remote timing
source, such as the timing pulse generator 267 via the timing
distribution network 268 (FIG. 2F) and/or the timing reference 257
via the switching network 258 (FIG. 2E). The counter 276 is in
communication with the first port 280', receiving therefrom a
timing reference signal. The counter 276 is also in communication
with the adjustable LO 277. For example the counter may receive a
sample of the adjusted LO output at the LO frequency. The counter
276 may be adapted to count cycles of the adjusted LO output
occurring between consecutive timing pulses, e.g., between
consecutive pulses of the first switched pulse 288a (FIG. 2G).
Accordingly, initiation of pulse counting may occur upon receipt of
the first switched pulse 288a. Counting of the adjusted LO output
cycles may continue until a subsequent pulse is provided according
to the first switched pulse 288a, e.g., after a time period T. Upon
detection of the subsequent pulse, the count value may be provided
and/or otherwise forwarded to the error detector 278. In at least
some embodiments, the counter is reinitialized, e.g., reset, and
begins a second subsequent counting output cycles of the adjusted
LO 277.
[0110] The error detector 278 compares the count value to a
reference count value. The error detector 278 may provide an
output, e.g., an error signal, indicative of a difference between
the count value obtained from the counter 276 and the reference
value. In some embodiments, the error signal may include a sign
indicating whether the difference is greater or lesser than the
reference value. Alternatively or in addition, the error signal may
include a magnitude indicative of a magnitude of the difference.
The error signal may be provided to a control terminal of the
adjustable LO 277 to induce a change in an operating frequency of
the adjustable LO 277, such that the change tends to direct the
adjusted LO output of the adjustable LO 277 to a synchronized
value. It is understood that in at least some embodiments, a loop
filter may be provided between the error detector 278 and the
control terminal of the adjustable LO 277. According to the
illustrative example, the loop filter includes an integrator. The
integrator integrates the error signal in order to provide a
control signal to the control terminal of the adjustable LO 277
that is adapted to establish and/or otherwise maintain the adjusted
LO output according to a synchronized value. It is understood that
similar corrected LOs 275 receiving respective different pulses
from the timing distribution network may operate in a like manner
to obtain adjusted LO outputs corresponding to a common
synchronized value. The adjusted LO output may be provided to an
output port or terminal 280''.
[0111] In summary and according to the illustrative example, the
counter 276 accumulates a number of LO cycles occurring within a
trigger period, T. A digital output of the counter, e.g., a number
may be compared to a reference number to determine a difference
between the two numbers. At least some general-purpose frequency
counters may include some form of amplifier, filtering and shaping
circuitry at the input. It is understood that at least some designs
may use a high-speed pre-scaler to bring the signal frequency down
to a point where normal digital circuitry can operate. An error
signal is determined from the output and may be integrated and used
to drive a voltage-controlled oscillator (VCO), by adjusting its
output in order to minimize count error. More generally, it is
understood that DSP technology, sensitivity control and hysteresis
are other techniques that may be incorporated to improve
performance. The adjusted LO output may be used to modulate and/or
demodulate and/or upconvert and/or down convert signals as may be
required according to operation of radio communication systems,
such as the example massive MIMO systems operating in the
millimeter wave spectrum.
[0112] FIG. 2I depicts an illustrative embodiment of a process 290
that establishes synchronization of large numbers of LOs operating
within a millimeter wave system in accordance with various aspects
described herein. A timing reference signal is generated at 291.
The timing signal reference may include a single timing reference,
e.g., a pulse train, that is obtained in a synchronous manner with
respect to a master oscillator. The timing signal may be an RF
signal and/or a digital signal. The timing signal may include
pulses provided at a pulse repetition frequency that is
substantially less than an LO frequency of any up and/or down
converters and/or any operational RF frequency of wireless signals
processed by the example radios.
[0113] Multiple timing signal segments may be obtained at 292 based
upon the reference timing signal. In some embodiments, the multiple
timing signals are obtained by a power division of the timing
reference signal. For example, the timing reference signal may be
divided by a power division circuit, such as the example device
disclosed herein, to obtain multiple, synchronized timing reference
signals. Alternatively or in addition, the multiple timing signals
may be obtained from a time-based slicing of the single pulse
signal. Different pulses of the single pulse train may be
demultiplexed and/or otherwise separated from the pulse train, such
that multiple independent, non-overlapping timing pulse signals are
obtained. Such a demultiplexing process may be accomplished by an
array of switches operated to sequentially switch sequential pulses
of the timing pulse train to different switched outputs. The
different switched timing signal segments may be provided to
different radio modules at 293, e.g., by routing the outputs of
different switches to different radio modules.
[0114] At each of the radio modules, cycles of a respective LO may
be counted at 294 to obtain a respective count value for each radio
module. For example, each radio module may include a counter that
is clocked by an adjusted LO output signal. The counter may have a
reset that resets the count to an initial value, e.g., "0." In at
least some embodiments, the reset may be connected to a respective
switched timing signal, such that the counter obtains a count
equivalent to a number of adjusted LO cycles between consecutive
pulses of the switched timing signal.
[0115] At each of the radio modules, differences between the
respective count values and a reference value are determined at
295. For example, the count value obtained at 294 may be compared
to a reference value, such as a target, synchronized LO frequency.
A difference between the count value and the reference value
provides a measure of a departure from the adjusted LO to the
target, synchronized LO frequency. The difference value may be used
to generate an error signal that may be used to adjust the
adjustable LO in a corrective manner, bring its operating frequency
into conformity with the target, synchronized LO frequency. Namely,
at each of the radio modules, a respective LO is adjusted at 296
according to a respective count difference to obtain an adjusted LO
signal. Consequently, the adjusted count signals of the multiple
radio modules trend towards synchronization with respect to each
other. The process may be implemented across all radio modules and
repeated in a periodic, aperiodic and/or substantially continuous
manner.
[0116] In at least some embodiments, a spatially diverse wireless
signal may be received that may include a spatially multiplexed
signal and/or spatially diverse signals resulting from multipath
propagation between a transmitter portion 201 and a receiver
portion 202 (FIG. 2A). In at least some embodiments, the spatially
diverse wireless signal may be obtained according to a MIMO
process, such as those described in association with new radio
and/or Next Generation Long Term Evolution LTE) wireless radio
communications. In at least some embodiments, the receiving is
accomplished using a transducer, such as an antenna element 211
(FIG. 2B) adapted to generate a received RF signal at an antenna
terminal 212 (FIG. 2B) of the antenna 211 responsive to the
spatially diverse wireless signal impingent upon the antenna
element 211.
[0117] A received RF signal may be combined with a synchronized LO
signal obtained according to the techniques disclosed herein. In at
least some embodiments, the synchronized LO signal is a low-power
LO signal. A combining of synchronized LO with the received signals
may be accomplished by summing the signals in a power sense.
[0118] The combined signal may be coupled to an energy detector of
the RF processing/detection module 215 (FIG. 2B), such as a diode.
The coupling may be accomplished by an electrical conductor, e.g.,
a transmission line extending between the antenna terminal 212 and
the energy detector. Alternatively or in addition, the coupling may
include one or more of an antenna coupler 213 (FIG. 2B), a balun, a
filter, and the like.
[0119] In at least some embodiments, signal conditioning may be
applied in any one or more of the signal paths disclosed herein.
Signal paths may include transmit and/or received RF signal paths,
LO signal paths, timing distribution signal paths, switched timing
signal paths, and the like. Signal conditioning may include an
application of amplitude and/or gain. For example, a received RF
signal is amplified, e.g., by an LNA 214 (FIG. 2B) before being
applied to a detector of the RF processing/detection module 215.
Other signal conditioning may include attenuating interference.
Still other signal conditioning may include matching networks,
baluns and the like.
[0120] The techniques disclosed herein may be used in combination
with low-resolution transmitters and/or receivers. For example, a
baseband signal may be detected from a received RF signal combined,
e.g., summed, with an adjusted LO signal. For example, a detector
may be adapted to detect baseband information from the received RF
signal, the baseband being obtained by a mixing performed at the
detector and/or diode. In particular, the mixing is facilitated by
the low-power operation of the LO. Namely, a maximum power of the
LO alone, or in combination with the received RF signal is
sufficiently low to preserve operation of the detector, e.g.,
diode, in a nonlinear region of its characteristic curve. This may
be accomplished, in the case of a diode detector by preventing the
junction from turning on.
[0121] For example, the detecting may detect an amplitude and/or an
envelope of the received RF signal. In at least some embodiments,
detection includes applying the received RF signal to a power
detector and applying a low-pass filter to the resulting signal.
Alternatively or in addition detection includes applying the
received RF signal to a square-law detector. In at least some
embodiments, the detecting includes applying the received RF signal
to an electrical device having a nonlinear I-V characteristic
curve. In at least some embodiments the electrical device may be an
active device, such as a transistor. Alternatively or in addition,
the electrical device may be a passive device, such as a diode.
[0122] In at least some embodiments, the detected signal may be
digitized. A digitizing process may be accomplished using a low
resolution, e.g., a single-bit ADC 217 (FIG. 2B). The ADC 217 may
include a nonlinear process, such as a comparison of the detected
signal to a reference, e.g., a threshold voltage. A value of a
digital output of the ADC 217 is determined according to a result
of the comparison to obtain a binary 1 or a binary 0, as the case
may be.
[0123] In at least some embodiments, estimates are obtained of
information transmitted over a wireless channel 208 (FIG. 2A) via a
spatially diverse wireless signal. In at least some embodiments,
the estimation is obtained via digital signal processing of digital
signals obtained from one or more MIMO radio cells 210 (FIG. 2B) or
modules 220 (FIG. 2C). Digital signal processing may include,
without limitation, a combining of digital signals obtained from at
least some of the cells 222, and/or modules 230.
[0124] It is envisioned that beamforming may be applied at a
spatial diversity transmitter, e.g., a MIMO transmitter. In
particular, a massively MIMO signal may employ beamforming to
direct MIMO signals to one or more particular spatially diverse
receivers. In at least some embodiments, beamforming may be applied
at the receiver, e.g., steering an antenna beam towards one or more
directions of the spatially diverse signals. However, according to
the various examples disclosed herein it is envisioned that the
example MIMO receiver portions 202 (FIG. 2A), MIMO cells 222 and/or
modules 220 (FIG. 2B) may operate without applying beamforming.
Such a relaxation with respect to beamforming relaxes spacing
and/or separation, and/or orientation of multiple antennas 211
(FIG. 2B). Likewise, such as relaxation of beamforming at the MIMO
receiver portion 202 is consistent with the overall low-power,
low-complexity architecture. Accordingly, phase control elements,
such as phase shifters, delay lines, and the like are unnecessary
at the receiver portion 202.
[0125] While for purposes of simplicity of explanation, the
respective processes are shown and described as a series of blocks
in FIG. 2I, it is to be understood and appreciated that the claimed
subject matter is not limited by the order of the blocks, as some
blocks may occur in different orders and/or concurrently with other
blocks from what is depicted and described herein. Moreover, not
all illustrated blocks may be required to implement the methods
described herein.
[0126] Referring now to FIG. 3, a block diagram is shown
illustrating an example, non-limiting embodiment of a virtualized
communication network 300 in accordance with various aspects
described herein. In particular a virtualized communication network
is presented that can be used to implement some or all of the
subsystems and functions of communication network 100, the
subsystems and functions of the example systems 200, modules or
devices 210, 220, 230, 245, 265, 278 and example process 290
presented in FIGS. 1, 2A, 2B, 2C, 2D, 2E, 2F, 2H, 2I and 3. For
example, virtualized communication network 300 can include
functionality 382, e.g., in one or more VNEs 332 adapted to
facilitate in whole or in part receiving, by a first radio module
at a first location, a wireless MIMO signal, to obtain a first
received RF signal. The wireless MIMO signal includes information
originating at a remote MIMO transmitter and conveyed via a
wireless channel. An envelope of the first received RF signal is
detected by the first radio module without requiring a local
oscillator, to obtain a first detected baseband signal. The first
detected baseband signal is compared to a reference value to obtain
a first digital signal that is provided to a digital processor. The
digital processor also obtains a second digital signal from a
second radio module receiving the wireless MIMO signal at a second
location and determines an estimate of the information originating
at the remote MIMO transmitter according to the first and second
digital signals.
[0127] In particular, a cloud networking architecture is shown that
leverages cloud technologies and supports rapid innovation and
scalability via a transport layer 350, a virtualized network
function cloud 325 and/or one or more cloud computing environments
375. In various embodiments, this cloud networking architecture is
an open architecture that leverages application programming
interfaces (APIs); reduces complexity from services and operations;
supports more nimble business models; and rapidly and seamlessly
scales to meet evolving customer requirements including traffic
growth, diversity of traffic types, and diversity of performance
and reliability expectations.
[0128] In contrast to traditional network elements--which are
typically integrated to perform a single function, the virtualized
communication network employs virtual network elements (VNEs) 330,
332, 334, etc., that perform some or all of the functions of
network elements 150, 152, 154, 156, etc., For example, the network
architecture can provide a substrate of networking capability,
often called Network Function Virtualization Infrastructure (NFVI)
or simply infrastructure that is capable of being directed with
software and Software Defined Networking (SDN) protocols to perform
a broad variety of network functions and services. This
infrastructure can include several types of substrates. The most
typical type of substrate being servers that support Network
Function Virtualization (NFV), followed by packet forwarding
capabilities based on generic computing resources, with specialized
network technologies brought to bear when general purpose
processors or general purpose integrated circuit devices offered by
merchants (referred to herein as merchant silicon) are not
appropriate. In this case, communication services can be
implemented as cloud-centric workloads.
[0129] As an example, a traditional network element 150 (shown in
FIG. 1), such as an edge router can be implemented via a VNE 330
composed of NFV software modules, merchant silicon, and associated
controllers. The software can be written so that increasing
workload consumes incremental resources from a common resource
pool, and moreover so that it is elastic: so the resources are only
consumed when needed. In a similar fashion, other network elements
such as other routers, switches, edge caches, and middle-boxes are
instantiated from the common resource pool. Such sharing of
infrastructure across a broad set of uses makes planning and
growing infrastructure easier to manage.
[0130] In an embodiment, the transport layer 350 includes fiber,
cable, wired and/or wireless transport elements, network elements
and interfaces to provide broadband access 110, wireless access
120, voice access 130, media access 140 and/or access to content
sources 175 for distribution of content to any or all of the access
technologies. In particular, in some cases a network element needs
to be positioned at a specific place, and this allows for less
sharing of common infrastructure. Other times, the network elements
have specific physical layer adapters that cannot be abstracted or
virtualized and might require special DSP code and analog
front-ends (AFEs) that do not lend themselves to implementation as
VNEs 330, 332 or 334. These network elements can be included in
transport layer 350. It is understood that in at least some
embodiments, the wireless access 120 may be adapted to include a
low-power MIMO radio 383 having an OOK and/or PSK transmitter,
and/or an OOK and/or PSK receiver and/or an OOK and/or PSK
transceiver according to the low-power, low-complexity radios and
related devices disclosed herein.
[0131] The virtualized network function cloud 325 interfaces with
the transport layer 350 to provide the VNEs 330, 332, 334, etc., to
provide specific NFVs. In particular, the virtualized network
function cloud 325 leverages cloud operations, applications, and
architectures to support networking workloads. The virtualized
network elements 330, 332 and 334 can employ network function
software that provides either a one-for-one mapping of traditional
network element function or alternately some combination of network
functions designed for cloud computing. For example, VNEs 330, 332
and 334 can include route reflectors, domain name system (DNS)
servers, and dynamic host configuration protocol (DHCP) servers,
system architecture evolution (SAE) and/or mobility management
entity (MME) gateways, broadband network gateways, IP edge routers
for IP-VPN, Ethernet and other services, load balancers,
distributers and other network elements. Because these elements
don't typically need to forward large amounts of traffic, their
workload can be distributed across a number of servers--each of
which adds a portion of the capability, and overall which creates
an elastic function with higher availability than its former
monolithic version. These virtual network elements 330, 332, 334,
etc., can be instantiated and managed using an orchestration
approach similar to those used in cloud compute services.
[0132] The cloud computing environments 375 can interface with the
virtualized network function cloud 325 via APIs that expose
functional capabilities of the VNEs 330, 332, 334, etc., to provide
the flexible and expanded capabilities to the virtualized network
function cloud 325. In particular, network workloads may have
applications distributed across the virtualized network function
cloud 325 and cloud computing environment 375 and in the commercial
cloud or might simply orchestrate workloads supported entirely in
NFV infrastructure from these third-party locations.
[0133] Turning now to FIG. 4, there is illustrated a block diagram
of a computing environment in accordance with various aspects
described herein. In order to provide additional context for
various embodiments of the embodiments described herein, FIG. 4 and
the following discussion are intended to provide a brief, general
description of a suitable computing environment 400 in which the
various embodiments of the subject disclosure can be implemented.
In particular, computing environment 400 can be used in the
implementation of network elements 150, 152, 154, 156, access
terminal 112, base station or access point 122, switching device
132, media terminal 142, and/or VNEs 330, 332, 334, etc. Each of
these devices can be implemented via computer-executable
instructions that can run on one or more computers, and/or in
combination with other program modules and/or as a combination of
hardware and software. For example, computing environment 400 can
facilitate in whole or in part receiving, by a first radio module
at a first location, a wireless MIMO signal, to obtain a first
received RF signal. The wireless MIMO signal includes information
originating at a remote MIMO transmitter and conveyed via a
wireless channel. An envelope of the first received RF signal is
detected by the first radio module without requiring a local
oscillator, to obtain a first detected baseband signal. The first
detected baseband signal is compared to a reference value to obtain
a first digital signal that is provided to a digital processor. The
digital processor also obtains a second digital signal from a
second radio module receiving the wireless MIMO signal at a second
location and determines an estimate of the information originating
at the remote MIMO transmitter according to the first and second
digital signals.
[0134] Generally, program modules comprise routines, programs,
components, data structures, etc., that perform particular tasks or
implement particular abstract data types. Moreover, those skilled
in the art will appreciate that the methods can be practiced with
other computer system configurations, comprising single-processor
or multiprocessor computer systems, minicomputers, mainframe
computers, as well as personal computers, hand-held computing
devices, microprocessor-based or programmable consumer electronics,
and the like, each of which can be operatively coupled to one or
more associated devices.
[0135] As used herein, a processing circuit includes one or more
processors as well as other application specific circuits such as
an application specific integrated circuit, digital logic circuit,
state machine, programmable gate array or other circuit that
processes input signals or data and that produces output signals or
data in response thereto. It should be noted that while any
functions and features described herein in association with the
operation of a processor could likewise be performed by a
processing circuit.
[0136] The illustrated embodiments of the embodiments herein can be
also practiced in distributed computing environments where certain
tasks are performed by remote processing devices that are linked
through a communications network. In a distributed computing
environment, program modules can be located in both local and
remote memory storage devices.
[0137] Computing devices typically comprise a variety of media,
which can comprise computer-readable storage media and/or
communications media, which two terms are used herein differently
from one another as follows. Computer-readable storage media can be
any available storage media that can be accessed by the computer
and comprises both volatile and nonvolatile media, removable and
non-removable media. By way of example, and not limitation,
computer-readable storage media can be implemented in connection
with any method or technology for storage of information such as
computer-readable instructions, program modules, structured data or
unstructured data.
[0138] Computer-readable storage media can comprise, but are not
limited to, random access memory (RAM), read only memory (ROM),
electrically erasable programmable read only memory (EEPROM), flash
memory or other memory technology, compact disk read only memory
(CD-ROM), digital versatile disk (DVD) or other optical disk
storage, magnetic cassettes, magnetic tape, magnetic disk storage
or other magnetic storage devices or other tangible and/or
non-transitory media which can be used to store desired
information. In this regard, the terms "tangible" or
"non-transitory" herein as applied to storage, memory or
computer-readable media, are to be understood to exclude only
propagating transitory signals per se as modifiers and do not
relinquish rights to all standard storage, memory or
computer-readable media that are not only propagating transitory
signals per se.
[0139] Computer-readable storage media can be accessed by one or
more local or remote computing devices, e.g., via access requests,
queries, or other data retrieval protocols, for a variety of
operations with respect to the information stored by the
medium.
[0140] Communications media typically embody computer-readable
instructions, data structures, program modules or other structured
or unstructured data in a data signal such as a modulated data
signal, e.g., a carrier wave or other transport mechanism, and
comprises any information delivery or transport media. The term
"modulated data signal" or signals refers to a signal that has one
or more of its characteristics set or changed in such a manner as
to encode information in one or more signals. By way of example,
and not limitation, communication media comprise wired media, such
as a wired network or direct-wired connection, and wireless media
such as acoustic, RF, infrared and other wireless media.
[0141] With reference again to FIG. 4, the example environment can
comprise a computer 402, the computer 402 comprising a processing
unit 404, a system memory 406 and a system bus 408. The system bus
408 couples system components including, but not limited to, the
system memory 406 to the processing unit 404. The processing unit
404 can be any of various commercially available processors. Dual
microprocessors and other multiprocessor architectures can also be
employed as the processing unit 404.
[0142] The system bus 408 can be any of several types of bus
structure that can further interconnect to a memory bus (with or
without a memory controller), a peripheral bus, and a local bus
using any of a variety of commercially available bus architectures.
The system memory 406 comprises ROM 410 and RAM 412. A basic
input/output system (BIOS) can be stored in a non-volatile memory
such as ROM, erasable programmable read only memory (EPROM),
EEPROM, which BIOS contains the basic routines that help to
transfer information between elements within the computer 402, such
as during startup. The RAM 412 can also comprise a high-speed RAM
such as static RAM for caching data.
[0143] The computer 402 further comprises an internal hard disk
drive (HDD) 414 (e.g., EIDE, SATA), which internal HDD 414 can also
be configured for external use in a suitable chassis (not shown), a
magnetic floppy disk drive (FDD) 416, (e.g., to read from or write
to a removable diskette 418) and an optical disk drive 420, (e.g.,
reading a CD-ROM disk 422 or, to read from or write to other high
capacity optical media such as the DVD). The HDD 414, magnetic FDD
416 and optical disk drive 420 can be connected to the system bus
408 by a hard disk drive interface 424, a magnetic disk drive
interface 426 and an optical drive interface 428, respectively. The
hard disk drive interface 424 for external drive implementations
comprises at least one or both of Universal Serial Bus (USB) and
Institute of Electrical and Electronics Engineers (IEEE) 1394
interface technologies. Other external drive connection
technologies are within contemplation of the embodiments described
herein.
[0144] The drives and their associated computer-readable storage
media provide nonvolatile storage of data, data structures,
computer-executable instructions, and so forth. For the computer
402, the drives and storage media accommodate the storage of any
data in a suitable digital format. Although the description of
computer-readable storage media above refers to a hard disk drive
(HDD), a removable magnetic diskette, and a removable optical media
such as a CD or DVD, it should be appreciated by those skilled in
the art that other types of storage media which are readable by a
computer, such as zip drives, magnetic cassettes, flash memory
cards, cartridges, and the like, can also be used in the example
operating environment, and further, that any such storage media can
contain computer-executable instructions for performing the methods
described herein.
[0145] A number of program modules can be stored in the drives and
RAM 412, comprising an operating system 430, one or more
application programs 432, other program modules 434 and program
data 436. All or portions of the operating system, applications,
modules, and/or data can also be cached in the RAM 412. The systems
and methods described herein can be implemented utilizing various
commercially available operating systems or combinations of
operating systems.
[0146] A user can enter commands and information into the computer
402 through one or more wired/wireless input devices, e.g., a
keyboard 438 and a pointing device, such as a mouse 440. Other
input devices (not shown) can comprise a microphone, an infrared
(IR) remote control, a joystick, a game pad, a stylus pen, touch
screen or the like. These and other input devices are often
connected to the processing unit 404 through an input device
interface 442 that can be coupled to the system bus 408, but can be
connected by other interfaces, such as a parallel port, an IEEE
1394 serial port, a game port, a universal serial bus (USB) port,
an IR interface, etc.
[0147] A monitor 444 or other type of display device can be also
connected to the system bus 408 via an interface, such as a video
adapter 446. It will also be appreciated that in alternative
embodiments, a monitor 444 can also be any display device (e.g.,
another computer having a display, a smart phone, a tablet
computer, etc.) for receiving display information associated with
computer 402 via any communication means, including via the
Internet and cloud-based networks. In addition to the monitor 444,
a computer typically comprises other peripheral output devices (not
shown), such as speakers, printers, etc.
[0148] The computer 402 can operate in a networked environment
using logical connections via wired and/or wireless communications
to one or more remote computers, such as a remote computer(s) 448.
The remote computer(s) 448 can be a workstation, a server computer,
a router, a personal computer, portable computer,
microprocessor-based entertainment appliance, a peer device or
other common network node, and typically comprises many or all of
the elements described relative to the computer 402, although, for
purposes of brevity, only a remote memory/storage device 450 is
illustrated. The logical connections depicted comprise
wired/wireless connectivity to a local area network (LAN) 452
and/or larger networks, e.g., a wide area network (WAN) 454. Such
LAN and WAN networking environments are commonplace in offices and
companies, and facilitate enterprise-wide computer networks, such
as intranets, all of which can connect to a global communications
network, e.g., the Internet.
[0149] When used in a LAN networking environment, the computer 402
can be connected to the LAN 452 through a wired and/or wireless
communication network interface or adapter 456. The adapter 456 can
facilitate wired or wireless communication to the LAN 452, which
can also comprise a wireless AP disposed thereon for communicating
with the adapter 456.
[0150] When used in a WAN networking environment, the computer 402
can comprise a modem 458 or can be connected to a communications
server on the WAN 454 or has other means for establishing
communications over the WAN 454, such as by way of the Internet.
The modem 458, which can be internal or external and a wired or
wireless device, can be connected to the system bus 408 via the
input device interface 442. In a networked environment, program
modules depicted relative to the computer 402 or portions thereof,
can be stored in the remote memory/storage device 450. It will be
appreciated that the network connections shown are example and
other means of establishing a communications link between the
computers can be used.
[0151] The computer 402 can be operable to communicate with any
wireless devices or entities operatively disposed in wireless
communication, e.g., a printer, scanner, desktop and/or portable
computer, portable data assistant, communications satellite, any
piece of equipment or location associated with a wirelessly
detectable tag (e.g., a kiosk, news stand, restroom), and
telephone. This can comprise Wireless Fidelity (Wi-Fi) and
BLUETOOTH.RTM. wireless technologies. Thus, the communication can
be a predefined structure as with a conventional network or simply
an ad hoc communication between at least two devices.
[0152] Wi-Fi can allow connection to the Internet from a couch at
home, a bed in a hotel room or a conference room at work, without
wires. Wi-Fi is a wireless technology similar to that used in a
cell phone that enables such devices, e.g., computers, to send and
receive data indoors and out; anywhere within the range of a base
station. Wi-Fi networks use radio technologies called IEEE 802.11
(a, b, g, n, ac, ag, etc.) to provide secure, reliable, fast
wireless connectivity. A Wi-Fi network can be used to connect
computers to each other, to the Internet, and to wired networks
(which can use IEEE 802.3 or Ethernet). Wi-Fi networks operate in
the unlicensed 2.4 and 5 GHz radio bands for example or with
products that contain both bands (dual band), so the networks can
provide real-world performance similar to the basic 10BaseT or
100BaseT wired Ethernet networks used in many offices.
[0153] Turning now to FIG. 5, an embodiment 500 of a mobile network
platform 510 is shown that is an example of network elements 150,
152, 154, 156, and/or VNEs 330, 332, 334, etc. For example,
platform 510 can facilitate in whole or in part receiving, by a
first radio module at a first location, a wireless MIMO signal, to
obtain a first received RF signal. The wireless MIMO signal
includes information originating at a remote MIMO transmitter and
conveyed via a wireless channel. An envelope of the first received
RF signal is detected by the first radio module without requiring a
local oscillator, to obtain a first detected baseband signal. The
first detected baseband signal is compared to a reference value to
obtain a first digital signal that is provided to a digital
processor. The digital processor also obtains a second digital
signal from a second radio module receiving the wireless MIMO
signal at a second location and determines an estimate of the
information originating at the remote MIMO transmitter according to
the first and second digital signals. In one or more embodiments,
the mobile network platform 510 can generate and receive signals
transmitted and received by base stations or access points such as
base station or access point 122. Generally, mobile network
platform 510 can comprise components, e.g., nodes, gateways,
interfaces, servers, or disparate platforms, that facilitate both
packet-switched (PS) (e.g., internet protocol (IP), frame relay,
asynchronous transfer mode (ATM)) and circuit-switched (CS) traffic
(e.g., voice and data), as well as control generation for networked
wireless telecommunication. As a non-limiting example, mobile
network platform 510 can be included in telecommunications carrier
networks and can be considered carrier-side components as discussed
elsewhere herein. Mobile network platform 510 comprises CS gateway
node(s) 512 which can interface CS traffic received from legacy
networks like telephony network(s) 540 (e.g., public switched
telephone network (PSTN), or public land mobile network (PLMN)) or
a signaling system #7 (SS7) network 560. CS gateway node(s) 512 can
authorize and authenticate traffic (e.g., voice) arising from such
networks. Additionally, CS gateway node(s) 512 can access mobility,
or roaming, data generated through SS7 network 560; for instance,
mobility data stored in a visited location register (VLR), which
can reside in memory 530. Moreover, CS gateway node(s) 512
interfaces CS-based traffic and signaling and PS gateway node(s)
518. As an example, in a 3GPP UMTS network, CS gateway node(s) 512
can be realized at least in part in gateway GPRS support node(s)
(GGSN). It should be appreciated that functionality and specific
operation of CS gateway node(s) 512, PS gateway node(s) 518, and
serving node(s) 516, is provided and dictated by radio
technology(ies) utilized by mobile network platform 510 for
telecommunication over a radio access network 520 with other
devices, such as a radiotelephone 575.
[0154] In addition to receiving and processing CS-switched traffic
and signaling, PS gateway node(s) 518 can authorize and
authenticate PS-based data sessions with served mobile devices.
Data sessions can comprise traffic, or content(s), exchanged with
networks external to the mobile network platform 510, like wide
area network(s) (WANs) 550, enterprise network(s) 570, and service
network(s) 580, which can be embodied in local area network(s)
(LANs), can also be interfaced with mobile network platform 510
through PS gateway node(s) 518. It is to be noted that WANs 550 and
enterprise network(s) 570 can embody, at least in part, a service
network(s) like IP multimedia subsystem (IMS). Based on radio
technology layer(s) available in technology resource(s) or radio
access network 520, PS gateway node(s) 518 can generate packet data
protocol contexts when a data session is established; other data
structures that facilitate routing of packetized data also can be
generated. To that end, in an aspect, PS gateway node(s) 518 can
comprise a tunnel interface (e.g., tunnel termination gateway (TTG)
in 3GPP UMTS network(s) (not shown)) which can facilitate
packetized communication with disparate wireless network(s), such
as Wi-Fi networks.
[0155] In embodiment 500, mobile network platform 510 also
comprises serving node(s) 516 that, based upon available radio
technology layer(s) within technology resource(s) in the radio
access network 520, convey the various packetized flows of data
streams received through PS gateway node(s) 518. It is to be noted
that for technology resource(s) that rely primarily on CS
communication, server node(s) can deliver traffic without reliance
on PS gateway node(s) 518; for example, server node(s) can embody
at least in part a mobile switching center. As an example, in a
3GPP UMTS network, serving node(s) 516 can be embodied in serving
GPRS support node(s) (SGSN).
[0156] For radio technologies that exploit packetized
communication, server(s) 514 in mobile network platform 510 can
execute numerous applications that can generate multiple disparate
packetized data streams or flows, and manage (e.g., schedule,
queue, format . . . ) such flows. Such application(s) can comprise
add-on features to standard services (for example, provisioning,
billing, customer support . . . ) provided by mobile network
platform 510. Data streams (e.g., content(s) that are part of a
voice call or data session) can be conveyed to PS gateway node(s)
518 for authorization/authentication and initiation of a data
session, and to serving node(s) 516 for communication thereafter.
In addition to application server, server(s) 514 can comprise
utility server(s), a utility server can comprise a provisioning
server, an operations and maintenance server, a security server
that can implement at least in part a certificate authority and
firewalls as well as other security mechanisms, and the like. In an
aspect, security server(s) secure communication served through
mobile network platform 510 to ensure network's operation and data
integrity in addition to authorization and authentication
procedures that CS gateway node(s) 512 and PS gateway node(s) 518
can enact. Moreover, provisioning server(s) can provision services
from external network(s) like networks operated by a disparate
service provider; for instance, WAN 550 or Global Positioning
System (GPS) network(s) (not shown). Provisioning server(s) can
also provision coverage through networks associated to mobile
network platform 510 (e.g., deployed and operated by the same
service provider), such as the distributed antennas networks shown
in FIG. 1(s) that enhance wireless service coverage by providing
more network coverage.
[0157] In at least some embodiments, the base station or access RAN
520 may be adapted to include a low-power MIMO radio 582 having an
OOK and/or PSK transmitter, and/or an OOK and/or PSK receiver
and/or an OOK and/or PSK transceiver according to the low-power,
low-complexity radios and related devices disclosed herein.
Likewise, in at least some embodiments, the mobile device 575 may
be adapted to include a low-power MIMO radio 583 having an OOK
and/or PSK transmitter, and/or an OOK and/or PSK receiver and/or an
OOK and/or PSK transceiver according to the low-power,
low-complexity radios and related devices disclosed herein.
[0158] It is to be noted that server(s) 514 can comprise one or
more processors configured to confer at least in part the
functionality of mobile network platform 510. To that end, the one
or more processor can execute code instructions stored in memory
530, for example. It should be appreciated that server(s) 514 can
comprise a content manager, which operates in substantially the
same manner as described hereinbefore.
[0159] In example embodiment 500, memory 530 can store information
related to operation of mobile network platform 510. Other
operational information can comprise provisioning information of
mobile devices served through mobile network platform 510,
subscriber databases; application intelligence, pricing schemes,
e.g., promotional rates, flat-rate programs, couponing campaigns;
technical specification(s) consistent with telecommunication
protocols for operation of disparate radio, or wireless, technology
layers; and so forth. Memory 530 can also store information from at
least one of telephony network(s) 540, WAN 550, SS7 network 560, or
enterprise network(s) 570. In an aspect, memory 530 can be, for
example, accessed as part of a data store component or as a
remotely connected memory store.
[0160] In order to provide a context for the various aspects of the
disclosed subject matter, FIG. 5, and the following discussion, are
intended to provide a brief, general description of a suitable
environment in which the various aspects of the disclosed subject
matter can be implemented. While the subject matter has been
described above in the general context of computer-executable
instructions of a computer program that runs on a computer and/or
computers, those skilled in the art will recognize that the
disclosed subject matter also can be implemented in combination
with other program modules. Generally, program modules comprise
routines, programs, components, data structures, etc., that perform
particular tasks and/or implement particular abstract data
types.
[0161] Turning now to FIG. 6, an illustrative embodiment of a
communication device 600 is shown. The communication device 600 can
serve as an illustrative embodiment of devices such as data
terminals 114, mobile devices 124, vehicle 126, display devices 144
or other client devices for communication via either communications
network 125. For example, computing device 600 can facilitate in
whole or in part receiving, by a first radio module at a first
location, a wireless MIMO signal, to obtain a first received RF
signal. The wireless MIMO signal includes information originating
at a remote MIMO transmitter and conveyed via a wireless channel.
An envelope of the first received RF signal is detected by the
first radio module without requiring a local oscillator, to obtain
a first detected baseband signal. The first detected baseband
signal is compared to a reference value to obtain a first digital
signal that is provided to a digital processor. The digital
processor also obtains a second digital signal from a second radio
module receiving the wireless MIMO signal at a second location and
determines an estimate of the information originating at the remote
MIMO transmitter according to the first and second digital
signals.
[0162] The communication device 600 can comprise a wireline and/or
wireless transceiver 602 (herein transceiver 602), a user interface
(UI) 604, a power supply 614, a location receiver 616, a motion
sensor 618, an orientation sensor 620, and a controller 606 for
managing operations thereof. The transceiver 602 can support
short-range or long-range wireless access technologies such as
Bluetooth.RTM., ZigBee.RTM., WiFi, DECT, or cellular communication
technologies, just to mention a few (Bluetooth.RTM. and ZigBee.RTM.
are trademarks registered by the Bluetooth.RTM. Special Interest
Group and the ZigBee.RTM. Alliance, respectively). Cellular
technologies can include, for example, CDMA-1X, UMTS/HSDPA,
GSM/GPRS, TDMA/EDGE, EV/DO, WiMAX, SDR, LTE, as well as other next
generation wireless communication technologies as they arise. The
transceiver 602 can also be adapted to support circuit-switched
wireline access technologies (such as PSTN), packet-switched
wireline access technologies (such as TCP/IP, VoIP, etc.), and
combinations thereof.
[0163] The UI 604 can include a depressible or touch-sensitive
keypad 608 with a navigation mechanism such as a roller ball, a
joystick, a mouse, or a navigation disk for manipulating operations
of the communication device 600. The keypad 608 can be an integral
part of a housing assembly of the communication device 600 or an
independent device operably coupled thereto by a tethered wireline
interface (such as a USB cable) or a wireless interface supporting
for example Bluetooth.RTM.. The keypad 608 can represent a numeric
keypad commonly used by phones, and/or a QWERTY keypad with
alphanumeric keys. The UI 604 can further include a display 610
such as monochrome or color LCD (Liquid Crystal Display), OLED
(Organic Light Emitting Diode) or other suitable display technology
for conveying images to an end user of the communication device
600. In an embodiment where the display 610 is touch-sensitive, a
portion or all of the keypad 608 can be presented by way of the
display 610 with navigation features.
[0164] The display 610 can use touch screen technology to also
serve as a user interface for detecting user input. As a touch
screen display, the communication device 600 can be adapted to
present a user interface having graphical user interface (GUI)
elements that can be selected by a user with a touch of a finger.
The display 610 can be equipped with capacitive, resistive, or
other forms of sensing technology to detect how much surface area
of a user's finger has been placed on a portion of the touch screen
display. This sensing information can be used to control the
manipulation of the GUI elements or other functions of the user
interface. The display 610 can be an integral part of the housing
assembly of the communication device 600 or an independent device
communicatively coupled thereto by a tethered wireline interface
(such as a cable) or a wireless interface.
[0165] The UI 604 can also include an audio system 612 that
utilizes audio technology for conveying low volume audio (such as
audio heard in proximity of a human ear) and high-volume audio
(such as speakerphone for hands free operation). The audio system
612 can further include a microphone for receiving audible signals
of an end user. The audio system 612 can also be used for voice
recognition applications. The UI 604 can further include an image
sensor 613 such as a charged coupled device (CCD) camera for
capturing still or moving images.
[0166] The power supply 614 can utilize common power management
technologies such as replaceable and rechargeable batteries, supply
regulation technologies, and/or charging system technologies for
supplying energy to the components of the communication device 600
to facilitate long-range or short-range portable communications.
Alternatively, or in combination, the charging system can utilize
external power sources such as DC power supplied over a physical
interface such as a USB port or other suitable tethering
technologies.
[0167] The location receiver 616 can utilize location technology
such as a global positioning system (GPS) receiver capable of
assisted GPS for identifying a location of the communication device
600 based on signals generated by a constellation of GPS
satellites, which can be used for facilitating location services
such as navigation. The motion sensor 618 can utilize motion
sensing technology such as an accelerometer, a gyroscope, or other
suitable motion sensing technology to detect motion of the
communication device 600 in three-dimensional space. The
orientation sensor 620 can utilize orientation sensing technology
such as a magnetometer to detect the orientation of the
communication device 600 (north, south, west, and east, as well as
combined orientations in degrees, minutes, or other suitable
orientation metrics).
[0168] The communication device 600 can use the transceiver 602 to
also determine a proximity to a cellular, WiFi, Bluetooth.RTM., or
other wireless access points by sensing techniques such as
utilizing a received signal strength indicator (RSSI) and/or signal
time of arrival (TOA) or time of flight (TOF) measurements. The
controller 606 can utilize computing technologies such as a
microprocessor, a digital signal processor (DSP), programmable gate
arrays, application specific integrated circuits, and/or a video
processor with associated storage memory such as Flash, ROM, RAM,
SRAM, DRAM or other storage technologies for executing computer
instructions, controlling, and processing data supplied by the
aforementioned components of the communication device 600. In at
least some embodiments, the transceiver 602 may be adapted to
include a low-power MIMO radio 683 having an OOK and/or PSK
transmitter, and/or an OOK and/or PSK receiver and/or an OOK and/or
PSK transceiver according to the low-power, low-complexity radios
and related devices disclosed herein.
[0169] Other components not shown in FIG. 6 can be used in one or
more embodiments of the subject disclosure. For instance, the
communication device 600 can include a slot for adding or removing
an identity module such as a Subscriber Identity Module (SIM) card
or Universal Integrated Circuit Card (UICC). SIM or UICC cards can
be used for identifying subscriber services, executing programs,
storing subscriber data, and so on.
[0170] Although the example embodiments disclosed herein are
directed to MIMO applications, it is understood that the disclosed
techniques may be applied, without limitation, to other
applications. For example, whereas MIMO systems may use multiple
transmitters, it is understood that the receiver systems, devices,
and/or techniques disclosed herein may be used to receive and/or
otherwise process RF signals from a single transmitter. Likewise,
the receiver systems, devices, and/or techniques disclosed herein
may be used to receive and/or otherwise process RF signals from a
multiple different transmitters, not necessarily within a MIMO
context. It is conceivable that the receiver systems, devices,
and/or techniques disclosed herein may be used to process RF
signals received from remote transmitters and/or RF signals
received from a nearby, or even collocated transmitter. The RF
signals may be signals received via line of sight and/or signals
received by way of one or more reflections, e.g., vial multipath
and/or echo return as in a RADAR application.
[0171] The terms "first," "second," "third," and so forth, as used
in the claims, unless otherwise clear by context, is for clarity
only and does not otherwise indicate or imply any order in time.
For instance, "a first determination," "a second determination,"
and "a third determination," does not indicate or imply that the
first determination is to be made before the second determination,
or vice versa, etc.
[0172] In the subject specification, terms such as "store,"
"storage," "data store," data storage," "database," and
substantially any other information storage component relevant to
operation and functionality of a component, refer to "memory
components," or entities embodied in a "memory" or components
comprising the memory. It will be appreciated that the memory
components described herein can be either volatile memory or
nonvolatile memory, or can comprise both volatile and nonvolatile
memory, by way of illustration, and not limitation, volatile
memory, non-volatile memory, disk storage, and memory storage.
Further, nonvolatile memory can be included in read only memory
(ROM), programmable ROM (PROM), electrically programmable ROM
(EPROM), electrically erasable ROM (EEPROM), or flash memory.
Volatile memory can comprise random access memory (RAM), which acts
as external cache memory. By way of illustration and not
limitation, RAM is available in many forms such as synchronous RAM
(SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data
rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM
(SLDRAM), and direct Rambus RAM (DRRAM). Additionally, the
disclosed memory components of systems or methods herein are
intended to comprise, without being limited to comprising, these
and any other suitable types of memory.
[0173] Moreover, it will be noted that the disclosed subject matter
can be practiced with other computer system configurations,
comprising single-processor or multiprocessor computer systems,
mini-computing devices, mainframe computers, as well as personal
computers, hand-held computing devices (e.g., PDA, phone,
smartphone, watch, tablet computers, netbook computers, etc.),
microprocessor-based or programmable consumer or industrial
electronics, and the like. The illustrated aspects can also be
practiced in distributed computing environments where tasks are
performed by remote processing devices that are linked through a
communications network; however, some if not all aspects of the
subject disclosure can be practiced on stand-alone computers. In a
distributed computing environment, program modules can be located
in both local and remote memory storage devices.
[0174] In one or more embodiments, information regarding use of
services can be generated including services being accessed, media
consumption history, user preferences, and so forth. This
information can be obtained by various methods including user
input, detecting types of communications (e.g., video content vs.
audio content), analysis of content streams, sampling, and so
forth. The generating, obtaining and/or monitoring of this
information can be responsive to an authorization provided by the
user. In one or more embodiments, an analysis of data can be
subject to authorization from user(s) associated with the data,
such as an opt-in, an opt-out, acknowledgement requirements,
notifications, selective authorization based on types of data, and
so forth.
[0175] Some of the embodiments described herein can also employ
artificial intelligence (AI) to facilitate automating one or more
features described herein. The embodiments (e.g., in connection
with automatically identifying acquired cell sites that provide a
maximum value/benefit after addition to an existing communication
network) can employ various AI-based schemes for carrying out
various embodiments thereof. Moreover, the classifier can be
employed to determine a ranking or priority of each cell site of
the acquired network. A classifier is a function that maps an input
attribute vector, x=(x1, x2, x3, x4, . . . , xn), to a confidence
that the input belongs to a class, that is, f(x)=confidence
(class). Such classification can employ a probabilistic and/or
statistical-based analysis (e.g., factoring into the analysis
utilities and costs) to determine or infer an action that a user
desires to be automatically performed. A support vector machine
(SVM) is an example of a classifier that can be employed. The SVM
operates by finding a hypersurface in the space of possible inputs,
which the hypersurface attempts to split the triggering criteria
from the non-triggering events. Intuitively, this makes the
classification correct for testing data that is near, but not
identical to training data. Other directed and undirected model
classification approaches comprise, e.g., naive Bayes, Bayesian
networks, decision trees, neural networks, fuzzy logic models, and
probabilistic classification models providing different patterns of
independence can be employed. Classification as used herein also is
inclusive of statistical regression that is utilized to develop
models of priority.
[0176] As will be readily appreciated, one or more of the
embodiments can employ classifiers that are explicitly trained
(e.g., via a generic training data) as well as implicitly trained
(e.g., via observing UE behavior, operator preferences, historical
information, receiving extrinsic information). For example, SVMs
can be configured via a learning or training phase within a
classifier constructor and feature selection module. Thus, the
classifier(s) can be used to automatically learn and perform a
number of functions, including but not limited to determining
according to predetermined criteria which of the acquired cell
sites will benefit a maximum number of subscribers and/or which of
the acquired cell sites will add minimum value to the existing
communication network coverage, etc.
[0177] As used in some contexts in this application, in some
embodiments, the terms "component," "system" and the like are
intended to refer to, or comprise, a computer-related entity or an
entity related to an operational apparatus with one or more
specific functionalities, wherein the entity can be either
hardware, a combination of hardware and software, software, or
software in execution. As an example, a component may be, but is
not limited to being, a process running on a processor, a
processor, an object, an executable, a thread of execution,
computer-executable instructions, a program, and/or a computer. By
way of illustration and not limitation, both an application running
on a server and the server can be a component. One or more
components may reside within a process and/or thread of execution
and a component may be localized on one computer and/or distributed
between two or more computers. In addition, these components can
execute from various computer readable media having various data
structures stored thereon. The components may communicate via local
and/or remote processes such as in accordance with a signal having
one or more data packets (e.g., data from one component interacting
with another component in a local system, distributed system,
and/or across a network such as the Internet with other systems via
the signal). As another example, a component can be an apparatus
with specific functionality provided by mechanical parts operated
by electric or electronic circuitry, which is operated by a
software or firmware application executed by a processor, wherein
the processor can be internal or external to the apparatus and
executes at least a part of the software or firmware application.
As yet another example, a component can be an apparatus that
provides specific functionality through electronic components
without mechanical parts, the electronic components can comprise a
processor therein to execute software or firmware that confers at
least in part the functionality of the electronic components. While
various components have been illustrated as separate components, it
will be appreciated that multiple components can be implemented as
a single component, or a single component can be implemented as
multiple components, without departing from example
embodiments.
[0178] Further, the various embodiments can be implemented as a
method, apparatus or article of manufacture using standard
programming and/or engineering techniques to produce software,
firmware, hardware, or any combination thereof to control a
computer to implement the disclosed subject matter. The term
"article of manufacture" as used herein is intended to encompass a
computer program accessible from any computer-readable device or
computer-readable storage/communications media. For example,
computer readable storage media can include, but are not limited
to, magnetic storage devices (e.g., hard disk, floppy disk,
magnetic strips), optical disks (e.g., compact disk (CD), digital
versatile disk (DVD)), smart cards, and flash memory devices (e.g.,
card, stick, key drive). Of course, those skilled in the art will
recognize many modifications can be made to this configuration
without departing from the scope or spirit of the various
embodiments.
[0179] In addition, the words "example" and "exemplary" are used
herein to mean serving as an instance or illustration. Any
embodiment or design described herein as "example" or "exemplary"
is not necessarily to be construed as preferred or advantageous
over other embodiments or designs. Rather, use of the word example
or exemplary is intended to present concepts in a concrete fashion.
As used in this application, the term "or" is intended to mean an
inclusive "or" rather than an exclusive "or". That is, unless
specified otherwise or clear from context, "X employs A or B" is
intended to mean any of the natural inclusive permutations. That
is, if X employs A; X employs B; or X employs both A and B, then "X
employs A or B" is satisfied under any of the foregoing instances.
In addition, the articles "a" and "an" as used in this application
and the appended claims should generally be construed to mean "one
or more" unless specified otherwise or clear from context to be
directed to a singular form.
[0180] Moreover, terms such as "user equipment," "mobile station,"
"mobile," subscriber station," "access terminal," "terminal,"
"handset," "mobile device" (and/or terms representing similar
terminology) can refer to a wireless device utilized by a
subscriber or user of a wireless communication service to receive
or convey data, control, voice, video, sound, gaming or
substantially any data-stream or signaling-stream. The foregoing
terms are utilized interchangeably herein and with reference to the
related drawings.
[0181] Furthermore, the terms "user," "subscriber," "customer,"
"consumer" and the like are employed interchangeably throughout,
unless context warrants particular distinctions among the terms. It
should be appreciated that such terms can refer to human entities
or automated components supported through artificial intelligence
(e.g., a capacity to make inference based, at least, on complex
mathematical formalisms), which can provide simulated vision, sound
recognition and so forth.
[0182] As employed herein, the term "processor" can refer to
substantially any computing processing unit or device comprising,
but not limited to comprising, single-core processors;
single-processors with software multithread execution capability;
multi-core processors; multi-core processors with software
multithread execution capability; multi-core processors with
hardware multithread technology; parallel platforms; and parallel
platforms with distributed shared memory. Additionally, a processor
can refer to an integrated circuit, an application specific
integrated circuit (ASIC), a digital signal processor (DSP), a
field programmable gate array (FPGA), a programmable logic
controller (PLC), a complex programmable logic device (CPLD), a
discrete gate or transistor logic, discrete hardware components or
any combination thereof designed to perform the functions described
herein. Processors can exploit nano-scale architectures such as,
but not limited to, molecular and quantum-dot based transistors,
switches and gates, in order to optimize space usage or enhance
performance of user equipment. A processor can also be implemented
as a combination of computing processing units.
[0183] As used herein, terms such as "data storage," data storage,"
"database," and substantially any other information storage
component relevant to operation and functionality of a component,
refer to "memory components," or entities embodied in a "memory" or
components comprising the memory. It will be appreciated that the
memory components or computer-readable storage media, described
herein can be either volatile memory or nonvolatile memory or can
include both volatile and nonvolatile memory.
[0184] What has been described above includes mere examples of
various embodiments. It is, of course, not possible to describe
every conceivable combination of components or methodologies for
purposes of describing these examples, but one of ordinary skill in
the art can recognize that many further combinations and
permutations of the present embodiments are possible. Accordingly,
the embodiments disclosed and/or claimed herein are intended to
embrace all such alterations, modifications and variations that
fall within the spirit and scope of the appended claims.
Furthermore, to the extent that the term "includes" is used in
either the detailed description or the claims, such term is
intended to be inclusive in a manner similar to the term
"comprising" as "comprising" is interpreted when employed as a
transitional word in a claim.
[0185] In addition, a flow diagram may include a "start" and/or
"continue" indication. The "start" and "continue" indications
reflect that the steps presented can optionally be incorporated in
or otherwise used in conjunction with other routines. In this
context, "start" indicates the beginning of the first step
presented and may be preceded by other activities not specifically
shown. Further, the "continue" indication reflects that the steps
presented may be performed multiple times and/or may be succeeded
by other activities not specifically shown. Further, while a flow
diagram indicates a particular ordering of steps, other orderings
are likewise possible provided that the principles of causality are
maintained.
[0186] As may also be used herein, the term(s) "operably coupled
to", "coupled to", and/or "coupling" includes direct coupling
between items and/or indirect coupling between items via one or
more intervening items. Such items and intervening items include,
but are not limited to, junctions, communication paths, components,
circuit elements, circuits, functional blocks, and/or devices. As
an example of indirect coupling, a signal conveyed from a first
item to a second item may be modified by one or more intervening
items by modifying the form, nature or format of information in a
signal, while one or more elements of the information in the signal
are nevertheless conveyed in a manner than can be recognized by the
second item. In a further example of indirect coupling, an action
in a first item can cause a reaction on the second item, as a
result of actions and/or reactions in one or more intervening
items.
[0187] Although specific embodiments have been illustrated and
described herein, it should be appreciated that any arrangement
which achieves the same or similar purpose may be substituted for
the embodiments described or shown by the subject disclosure. The
subject disclosure is intended to cover any and all adaptations or
variations of various embodiments. Combinations of the above
embodiments, and other embodiments not specifically described
herein, can be used in the subject disclosure. For instance, one or
more features from one or more embodiments can be combined with one
or more features of one or more other embodiments. In one or more
embodiments, features that are positively recited can also be
negatively recited and excluded from the embodiment with or without
replacement by another structural and/or functional feature. The
steps or functions described with respect to the embodiments of the
subject disclosure can be performed in any order. The steps or
functions described with respect to the embodiments of the subject
disclosure can be performed alone or in combination with other
steps or functions of the subject disclosure, as well as from other
embodiments or from other steps that have not been described in the
subject disclosure. Further, more than or less than all of the
features described with respect to an embodiment can also be
utilized.
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