U.S. patent application number 17/170326 was filed with the patent office on 2021-06-03 for systems and methods for creating non-orthogonal dimensionality between signals in electronic devices.
The applicant listed for this patent is Collision Communications, Inc.. Invention is credited to Joseph Farkas, Jared Fry, Barry West.
Application Number | 20210167822 17/170326 |
Document ID | / |
Family ID | 1000005387346 |
Filed Date | 2021-06-03 |
United States Patent
Application |
20210167822 |
Kind Code |
A1 |
Farkas; Joseph ; et
al. |
June 3, 2021 |
SYSTEMS AND METHODS FOR CREATING NON-ORTHOGONAL DIMENSIONALITY
BETWEEN SIGNALS IN ELECTRONIC DEVICES
Abstract
Systems and methods for creating non-orthogonal dimensionality
between signals are disclosed. Signals are received from at least
one electronic device. An adjustment of a parameter of a received
signal of a first device of the at least one of the electronic
device that would result in an adjusted signal that is not
orthogonal but differentiates the signal from at least one other
signal of the received signals is determined. An instruction is
communicated to the first device to implement the adjustment of the
parameter.
Inventors: |
Farkas; Joseph; (Merrimack,
NH) ; Fry; Jared; (Boston, MA) ; West;
Barry; (Temple Hill, NH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Collision Communications, Inc. |
Peterborough |
NH |
US |
|
|
Family ID: |
1000005387346 |
Appl. No.: |
17/170326 |
Filed: |
February 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14733141 |
Jun 8, 2015 |
10917143 |
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17170326 |
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13900897 |
May 23, 2013 |
9055579 |
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14733141 |
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61650715 |
May 23, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 5/0092 20130101;
H04L 5/0062 20130101; H04B 15/00 20130101; H04W 72/042 20130101;
H04L 1/0036 20130101; H04L 1/06 20130101; H04L 1/0025 20130101;
H04J 11/003 20130101; H04B 7/0413 20130101 |
International
Class: |
H04B 7/0413 20060101
H04B007/0413; H04W 72/04 20060101 H04W072/04; H04J 11/00 20060101
H04J011/00; H04L 5/00 20060101 H04L005/00; H04L 1/00 20060101
H04L001/00; H04L 1/06 20060101 H04L001/06; H04B 15/00 20060101
H04B015/00 |
Claims
1. A method for creating non-orthogonal dimensionality between
signals, the method comprising: receiving signals from at least one
electronic device; determining an adjustment of a parameter of a
received signal of a first device of the at least one of the
electronic device that would result in an adjusted signal that is
not orthogonal but differentiates the signal from at least one
other signal of the received signals; and communicating, to the
first device, an instruction to implement the adjustment of the
parameter.
2. The method of claim 1, wherein receiving signals from at least
one electronic device includes receiving signals that overlap in at
least one of time and frequency.
3. The method of claim 1, further comprising decoding the signals
based on a multi-user detection technique.
4. The method of claim 1, further comprising decoding the signals
as multiple-input and multiple-output signals from a single
electronic device.
5. The method of claim 1, wherein receiving signals from at least
one electronic device includes receiving signals from at least one
of a wireless transmit/receive unit (WTRU), user equipment (UE), a
mobile station, a fixed subscriber unit, a mobile subscriber unit,
a cellular telephone, a personal digital assistant (PDA), a
smartphone, a laptop, a netbook, a personal computer, a wireless
sensor, and a consumer electronic device.
6. The method of claim 1, wherein determining an adjustment of a
parameter includes estimating the parameters of the signal of at
least one of the electronic devices.
7. The method of claim 1, wherein determining an adjustment of a
parameter includes determining an adjustment of at least one of the
symbol phase, power level, channel, modulation rate, transmit
symbol timing, coding rate, and time offset.
8. The method of claim 1, wherein determining an adjustment of a
parameter includes determining an adjustment of symbol phase such
that the adjustment results in the phase of the adjusted signal of
being different than the phase of one or more other received
signals.
9. The method of claim 8, wherein determining an adjustment of
symbol phase comprises setting the adjustment such that a symbol
phase offset between the adjusted signal and one or more other
received signals is linearly spaced between two angles.
10. The method of claim 8, wherein determining an adjustment of
symbol phase comprises setting the adjustment such that a symbol
phase offset within a grouping of electronic devices that include a
subset of the total number of electronic devices that are linearly
spaced between two angles.
11. The method of claim 8, further comprising: detecting a symbol
phase offset between the signals; and decoding the signals
partially or fully based on the detected symbol phase offset.
12. The method of claim 8, further comprising: determining an
adjustment of one of a power, channel, transmit symbol timing,
modulation rate, coding rate, and a time offset of at least one of
the first device and a second device of the at least one of the
electronic device that would result in an adjusted signal that is
not orthogonal but differentiates the signal from at least one
other signal of the received signals; and communicating, to the at
least one of the first device and a second device, an instruction
to implement the adjustment of the one of the power, channel,
transmit symbol timing, modulation rate, coding rate, and the time
offset.
13. The method of claim 1, wherein determining an adjustment of a
parameter includes determining an adjustment of power level such
that the adjustment results in the received power level of the
adjusted signal being different than the received power level of
one or more signals of other electronic devices.
14. The method of claim 13, wherein determining an adjustment of
power level comprises setting the adjustment such that a power
level difference between the adjusted signal and one or more other
received signals is one of linearly and exponentially spaced.
15. The method of claim 13, wherein determining an adjustment of
power level comprises setting the adjustment such that a power
level difference between groups of signals exists to aid a group
detector.
16. The method of claim 13, further comprising: detecting a power
level difference between the signals; and decoding the signals
partially or fully based on the detected power level
difference.
17. The method of claim 1, wherein the signals are received at one
or more of a different angle of arrival, channel, transmit symbol
timing, modulation rate, and coding rate, the method further
comprising: detecting the one or more of the different angle of
arrival, channel, transmit symbol timing, modulation rate, and
coding rate, and decoding the signals based on at least the
detected one or more of the different angle of arrival, channel,
transmit symbol timing, modulation rate, and coding rate.
18. A method comprising: receiving a first set of signals from a
first plurality of electronic devices, wherein the signals are
transmitted at the same time and on substantially the same
frequency or an overlapping frequency; receiving a second set of
signals from a second plurality of electronic devices, wherein the
second set of signals are transmitted on a different frequency than
the first set of signals; estimating the parameters of at least one
of the signals of the first set of signals; estimating the
parameters of at least one of the signals of the second set of
signals; and instructing an electronic device from the first
plurality of electronic devices to transmit on the frequency of the
second set of signals if at least one parameter of a signal from
the electronic device from the first plurality of electronic
devices is more diverse with those of the second set of signals
than with those of the first set of signals.
19. An electronic device comprising: at least a processor and
memory configured to: receive signals from at least one electronic
device; determine an adjustment of a parameter of a received signal
of a first device of the at least one of the electronic device that
would result in an adjusted signal that is not orthogonal but
differentiates the signal from at least one other signal of the
received signals; and communicate, to the first device, an
instruction to implement the adjustment of the parameter.
20. The electronic device of claim 19, wherein the signals arrive
at the electronic device overlapping in at least one of time and
frequency.
21. The electronic device of claim 19, further comprising decoding
the signals based on a multi-user detection technique.
22. The electronic device of claim 19, wherein the at least a
processor and memory are configured to decode the signals as
multiple-input and multiple-output signals from a single electronic
device.
23. The electronic device of claim 19, wherein the at least one
electronic device are one of a wireless transmit/receive unit
(WTRU), user equipment (UE), a mobile station, a fixed subscriber
unit, a mobile subscriber unit, a cellular telephone, a personal
digital assistant (PDA), a smartphone, a laptop, a netbook, a
personal computer, a wireless sensor, and a consumer electronic
device.
24. The electronic device of claim 19, wherein the at least a
processor and memory are configured to estimate the parameters of
the signal of at least one of the electronic devices.
25. The electronic device of claim 19, wherein the at least a
processor and memory are configured to determine an adjustment of
at least one of the symbol phase, power level, channel, transmit
symbol timing, modulation rate, coding rate, and time offset.
26. The electronic device of claim 19, wherein the at least a
processor and memory are configured to determine an adjustment of
phase such that the adjustment results in the phase of the adjusted
signal being different than the phase of one or more other received
signals.
27. The electronic device of claim 26, wherein the at least a
processor and memory are configured to set the adjustment such that
a symbol phase offset between the signals is linearly spaced
between two angles as seen by the receiver.
28. The electronic device of claim 26, wherein the at least a
processor and memory are configured to set the adjustment such that
a symbol phase offset within a grouping of users that include a
subset of the total number of users are linearly spaced between two
angles.
29. The electronic device of claim 26, wherein the at least a
processor and memory are configured to: detect a symbol phase
offset between the signals; and decode the signals partially or
fully based on the detected symbol phase offset.
30. The electronic device of claim 26, wherein the at least a
processor and memory are further configured to: determine an
adjustment of one of power, an angle of arrival, channel, transmit
symbol timing, modulation rate, coding rate, and a time offset of
at least one of the first device and a second device of the at
least one of the electronic device that would result in an adjusted
signal that is not orthogonal but differentiates the signal from at
least one other signal of the received signals; and communicating,
to the at least one of the first device and a second device, an
instruction to implement the adjustment of the one of the power,
the angle of arrival, channel, transmit symbol timing, modulation
rate, coding rate, and the time offset.
31. The electronic device of claim 19, wherein the at least a
processor and memory are configured to determine an adjustment of
power level such that the adjustment results in the power level of
the adjusted signal being different than the power level of one or
more other received signals.
32. The electronic device of claim 31, wherein the at least a
processor and memory are configured to set the adjustment such that
a power level difference between the adjusted signal and one or
more other received signals is one of linearly and exponentially
spaced.
33. The electronic device of claim 31, wherein the at least a
processor and memory are configured to set the adjustment such that
a power level difference between groups of signals exists to aid a
group detector.
34. The electronic device of claim 31, wherein the at least a
processor and memory are configured to: detect a power level
difference between the signals; and decode the signals partially or
fully based on the detected power level difference.
35. The electronic device of claim 19, wherein the signals are
received at one or more of a different angle of arrival, channel,
transmit symbol timing, modulation rate, and coding rate, wherein
the at least a processor and memory are configured to: detect the
one or more of the different angle of arrival, channel, transmit
symbol timing, modulation rate, and coding rate; and decode the
signals comprises decoding the signals based on the detected one or
more of the different angle of arrival, channel, transmit symbol
timing, modulation rate, and coding rate.
36. An electronic device comprising: at least a processor and
memory configured to: receive a first set of signals from a
plurality of electronic devices, wherein the signals are
transmitted at the same time and on substantially the same
frequency or an overlapping frequency; receive a second set of
signals from a plurality of electronic devices, wherein the second
set of signals are transmitted on a different frequency than the
first set of signals; estimate the parameters of at least one of
the signals of the first set of signals; estimate the parameters of
at least one of the signals of the second set of signals; and
instruct an electronic device from the first plurality of
electronic devices to transmit on the frequency of the second set
of signals if at least one parameter of a signal from the
electronic device from the first plurality of electronic devices is
more diverse with those of the second set of signals than with
those of the first set of signals.
37. A non-transitory computer readable medium storing a computer
program, executable by a machine, for creating non-orthogonal
dimensionality between signals, the computer program comprising
executable instructions for: receiving signals from at least one
electronic device; determining an adjustment of a parameter of a
received signal of a first device of the at least one of the
electronic device that would result in an adjusted signal that is
not orthogonal but differentiates the signal from at least one
other signal of the received signals; and communicating, to the
first device, an instruction to implement the adjustment of the
parameter.
38. A non-transitory computer readable medium storing a computer
program, executable by a machine, for creating non-orthogonal
dimensionality between signals, the computer program comprising
executable instructions for: receiving a first set of signals from
a first plurality of electronic devices, wherein the signals are
transmitted at the same time and on substantially the same
frequency or an overlapping frequency; receiving a second set of
signals from a second plurality of electronic devices, wherein the
second set of signals are transmitted on a different frequency than
the first set of signals; estimating the parameters of at least one
of the signals of the first set of signals; estimating the
parameters of at least one of the signals of the second set of
signals; and instructing an electronic device from the first
plurality of electronic devices to transmit on the frequency of the
second set of signals if at least one parameter of a signal from
the electronic device from the first plurality of electronic
devices is more diverse with those of the second set of signals
than with those of the first set of signals.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/733,141 titled "SYSTEMS AND METHODS FOR
CREATING NON-ORTHOGONAL DIMENSIONALITY BETWEEN SIGNALS IN
ELECTRONIC DEVICES", filed on Jun. 8, 2015, being issued as U.S.
Pat. No. 10,917,143 on Feb. 9, 2021, which is a continuation of
U.S. Pat. No. 9,055,579 titled "SYSTEMS AND METHODS FOR CREATING
NON-ORTHOGONAL DIMENSIONALITY BETWEEN SIGNALS IN ELECTRONIC
DEVICES," filed on May 23, 2013 as U.S. patent application Ser. No.
13/900,897, which claims priority to and the benefit of U.S.
Provisional Patent Application No. 61/650,715 titled "SYSTEMS AND
METHODS FOR CREATING DIMENSIONALITY BETWEEN SIGNALS FOR MULTI-USER
DETECTION (MUD) IN ELECTRONIC DEVICES", filed on May 23, 2012, the
entire disclosure of each of which is hereby incorporated by
reference.
BACKGROUND
[0002] Receivers in communications systems traditionally were not
designed to handle any interference, i.e. they were single user
receivers. Since the receiver could not handle interference,
communication systems were designed to avoid interference. This
typically has been accomplished through the orthogonal scheduling
of transmitting users and as part of multiple-access communication
schemes, such as FDMA, TDMA, and CDMA, where it is intended to
direct users to transmit in a non-interfering or orthogonal
manner.
[0003] Interference can come in a number of different forms, both
internal and external to the communication system. In a cellular
communications environment there may be intercellular interference,
i.e., interference that is caused by transmitters of a different,
usually adjacent, cell. In addition, there may be intracellular
interference, i.e., interference that is caused by transmitters of
the same cell. In addition to scheduling and multiple access
schemes to try and prevent interference, power control techniques
are used in a variety of ways to improve the performance of the
communication systems. Commonly, power control is used to reduce
the effects of intercellular and intracellular interference, and
more specifically "near-far" problems, by coordinating
transmitters, to transmit such that their powers are nearly the
same as received by the receiver, and as such, one transmission is
not obfuscating another because it is received at such a greater
power.
[0004] However, due to the demand for higher spectral efficiency,
interference and receivers that can handle interference have become
increasingly important, most notably receivers with Multi-User
Detection capabilities.
[0005] Multi-User Detection (MUD) works by exploiting
dimensionality between multiple interfering signals. The
dimensionality may occur naturally between interfering signals but
may also, as an aspect of the subject matter described herein, be
purposely introduced in order to create advantageous situations for
the MUD. The dimensionality can take the form of any difference
between the received signals that can be exploited by the MUD to
more reliably decode the interfering signals. Techniques to create
orthogonal dimensionality between signals by design are widely
employed with varying multiple access schemes, such as TDMA, FDMA,
CDMA, and OFDMA. However networks do not attempt to direct a
transmitter in real time to adjust transmit parameters in order to
create the dimensionality between interfering signals short of
scheduling an interfering transmitter to transmit at a different
orthogonal non-interfering time-slot or frequency.
[0006] Multiple-input and multiple-output (MIMO), generally
speaking, involves the use of multiple antennas at both the
transmitter and receiver to improve communication performance. MIMO
technology offers significant increases in data throughput and link
range without additional bandwidth or increased transmit power. It
achieves this goal by spreading the same total transmit power over
the antennas to achieve an array gain that improves the spectral
efficiency and/or to achieve a diversity gain that improves the
link reliability. MIMO results in multiple signals that must be
decoded and therefore can benefit from exploiting dimensionality
between the multiple signals.
[0007] Although techniques have been provided to handle
interference, it is desired to provide improved techniques for both
managing interfering signals and better utilizing available
resources.
SUMMARY
[0008] This Summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This Summary is not intended to identify
key features or essential features of the claimed subject matter,
nor is it intended to be used to limit the scope of the claimed
subject matter.
[0009] According to an aspect, a method for creating non-orthogonal
dimensionality between signals is disclosed. Signals are received
from at least one electronic device. An adjustment of a parameter
of a received signal of a first device of the at least one of the
electronic device that would result in an adjusted signal that is
not orthogonal but differentiates the signal from at least one
other signal of the received signals is determined. An instruction
is communicated to the first device to implement the adjustment of
the parameter.
[0010] According to an aspect, a method an electronic device
includes at least a processor and memory configured to: receive
signals from at least one electronic device; determine an
adjustment of a parameter of a received signal of a first device of
the at least one of the electronic device that would result in an
adjusted signal that is not orthogonal but differentiates the
signal from at least one other signal of the received signals; and
communicate, to the first device, an instruction to implement the
adjustment of the parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing summary, as well as the following detailed
description of various embodiments, is better understood when read
in conjunction with the appended drawings. For the purposes of
illustration, there is shown in the drawings exemplary embodiments;
however, the presently disclosed subject matter is not limited to
the specific methods and instrumentalities disclosed. In the
drawings:
[0012] FIG. 1A is a diagram of an example communications system in
which one or more disclosed embodiments may be implemented;
[0013] FIG. 1B is a system diagram of the example WTRU shown in
FIG. 1A;
[0014] FIG. 2 depicts two BPSK users' constellations as seen by a
receiver as well as the superposition of those constellations,
which occurs in the receiver's antenna;
[0015] FIG. 3 depicts user two's power being reduced to add the
dimensionality;
[0016] FIG. 4 depicts a scenario that uses phase offset in a symbol
synchronous case as dimensionality between the signals;
[0017] FIG. 5 is a flowchart of an example method according to
embodiments of the present disclosure;
[0018] FIG. 6 illustrates a flow chart of an example method for
receiving signals from different electronic devices, such as WTRUs,
and for communicating signaling adjustment information to one or
more of the electronic devices for distinguishing the signals in
accordance with embodiments of the present subject matter;
[0019] FIG. 7 illustrates a flow chart of another example method
for receiving signals from different electronic devices, such as
WTRUs, and for communicating signaling adjustment information to
one or more of the electronic devices for distinguishing the
signals in accordance with embodiments of the present subject
matter; and
[0020] FIG. 8 illustrates a flow chart of another example method
for receiving signals from different electronic devices, such as
WTRUs, and for communicating signaling adjustment information to
one or more of the electronic devices for distinguishing the
signals in accordance with embodiments of the present subject
matter.
DETAILED DESCRIPTION
[0021] The presently disclosed subject matter is described with
specificity to meet statutory requirements. However, the
description itself is not intended to limit the scope of this
patent. Rather, the inventors have contemplated that the claimed
subject matter might also be embodied in other ways, to include
different steps or elements similar to the ones described in this
document, in conjunction with other present or future technologies.
Moreover, although the term "step" may be used herein to connote
different aspects of methods employed, the term should not be
interpreted as implying any particular order among or between
various steps herein disclosed unless and except when the order of
individual steps is explicitly described.
[0022] It should also be understood that the various system
components defined by the claims, described below, and illustrated
in the various block diagrams represent logical components that are
configured to perform the functionality described herein. In
addition, while at least one of these components are implemented at
least partially as an electronic hardware component, and therefore
constitutes a machine, the other components may be implemented in
software, hardware, or a combination of software and hardware. More
particularly, at least one component defined by the claims is
implemented at least partially as an electronic hardware component,
such as an instruction execution machine (e.g., a processor-based
or processor-containing machine) and/or as specialized circuits or
circuitry (e.g., discrete logic gates interconnected to perform a
specialized function). Other components may be implemented in
software, hardware, or a combination of software and hardware.
Moreover, some or all of these other components may be combined,
some may be omitted altogether, and additional components can be
added while still achieving the functionality described herein.
Thus, the subject matter described herein can be embodied in many
different variations, and all such variations are contemplated to
be within the scope of what is claimed.
[0023] In the description that follows, the subject matter will be
described with reference to acts and symbolic representations of
operations that are performed by one or more devices, unless
indicated otherwise. As such, it will be understood that such acts
and operations, which are at times referred to as being
computer-executed, include the manipulation by the processing unit
of data in a structured form. This manipulation transforms the data
or maintains it at locations in the memory system of the computer,
which reconfigures or otherwise alters the operation of the device
in a manner well understood by those skilled in the art. The data
structures where data is maintained are physical locations of the
memory that have particular properties defined by the format of the
data. However, while the subject matter is being described in the
foregoing context, it is not meant to be limiting as those of skill
in the art will appreciate that various of the acts and operation
described hereinafter may also be implemented in hardware. FIG. 1A
is a diagram of an example communications system 100 in which one
or more disclosed embodiments may be implemented. The
communications system 100 may be a multiple access system that
provides content, such as voice, data, video, messaging, broadcast,
and the like, to multiple wireless users. The communications system
100 may enable multiple wireless users to access such content
through the sharing of system resources, including wireless
bandwidth. For example, the communications systems 100 may employ
one or more channel access methods, such as code division multiple
access (CDMA), time division multiple access (TDMA), frequency
division multiple access (FDMA), orthogonal FDMA (OFDMA),
single-carrier FDMA (SC-FDMA), and the like. Although depicted in
the example of FIG. 1A as a wireless communications system, a
system in accordance with the presently disclosed subject matter
may alternatively be implemented as a wired communications system
based on embodiments and examples disclosed herein.
[0024] As shown in FIG. 1A, the communications system 100 may
include wireless transmit/receive units (WTRUs) 102a, 102b, and
102c, a base station controller (BSC) 104, a core network 106, a
public switched telephone network (PSTN) 108, the Internet 110, and
other networks 112, though it will be appreciated that the
disclosed embodiments contemplate any number of WTRUs, base
stations, networks, and/or network elements. Each of the WTRUs
102a, 102b, and 102c may be any type of device configured to
operate and/or communicate in a wireless environment. By way of
example, the WTRUs 102a, 102b, and 102c may be configured to
transmit and/or receive wireless signals and may include user
equipment (UE), a mobile station, a fixed or mobile subscriber
unit, a pager, a cellular telephone, a personal digital assistant
(PDA), a smartphone, a laptop, a netbook, a personal computer, a
wireless sensor, consumer electronics, and the like. In an
embodiment, WTRU 102a may employ multiple-input multiple-output
(MIMO) technology and, therefore, may utilize multiple antennas
and/or multiple transceivers per device.
[0025] The communications systems 100 may also include a base
station 114a, a base station 114b, and a base station 114c. Each of
the base stations 114a, 114b, and 114c may be any type of device
configured to wirelessly interface with at least one of the WTRUs
102a, 102b, and 102c to facilitate access to one or more
communication networks, such as the core network 106, the Internet
110, and/or the networks 112 through the BSC 104, although more
than one BSC may also be used. By way of example, the base stations
114a, 114b, and 114c may be a base transceiver station (BTS), a
Node-B, an eNode B, a Home Node B, a Home eNode B, a site
controller, an access point (AP), a wireless router, and the like.
While the base stations 114a, 114b, and 114c are each depicted as a
single element, it will be appreciated that the base stations 114a,
114b, and 114c may include any number of interconnected base
stations and/or network elements.
[0026] The base station 114c may be part of a radio access network,
which may also include other base stations and/or network elements
(not shown), such as a base station controller (BSC), a radio
network controller (RNC), relay nodes, and the like. The base
station 114c and/or the base stations 114a and 114c may be
configured to transmit and/or receive wireless signals within a
particular geographic region, which may be referred to as a cell
(not shown). The cell may further be divided into cell sectors. For
example, the cell associated with the base stations 114a, 114b, and
114c may each be divided into three sectors, or a different number
of sectors. Thus, in one embodiment, a base station may include
three transceivers, i.e., one for each sector of the cell. In
another embodiment, the base station 114c may employ MIMO
technology and, therefore, may utilize multiple antennas and/or
multiple transceivers for each sector of the cell.
[0027] The base stations 114a, 114b, and 114c may communicate with
one or more of the WTRUs 102a, 102b, and 102c over an air interface
116, which may be any suitable wireless communication link (e.g.,
radio frequency (RF), microwave, infrared (IR), ultraviolet (UV),
visible light, etc.). The air interface 116 may be established
using any suitable radio access technology (RAT).
[0028] More specifically, as noted above, the communications system
100 may be a multiple access system and may employ one or more
channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA,
and the like. For example, the base stations 114a, 114b, and 114c
and the WTRUs 102a, 102b, and 102c may implement a radio technology
such as Universal Mobile Telecommunications System (UMTS)
Terrestrial Radio Access (UTRA), which may establish the air
interface 116 using wideband CDMA (WCDMA). WCDMA may include
communication protocols such as High-Speed Packet Access (HSPA)
and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink
Packet Access (HSDPA) and/or High-Speed Uplink Packet Access
(HSUPA).
[0029] In another embodiment, the base stations 114a, 114b, and
114c, and the WTRUs 102a, 102b, and 102c may implement a radio
technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA),
which may establish the air interface 116 using Long Term Evolution
(LTE) and/or LTE-Advanced (LTE-A).
[0030] In another embodiment, the base stations 114a, 114b, and
114c, and the WTRUs 102a, 102b, and 102c may implement a frequency
hopping radio technology such as Bluetooth of Zigby.
[0031] In other embodiments, the base stations 114a, 114b, and
114c, and the WTRUs 102a, 102b, 102c may implement radio
technologies such as IEEE 802.16 (i.e., Worldwide Interoperability
for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1.times.,
CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard
95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile
communications (GSM), Enhanced Data rates for GSM Evolution (EDGE),
GSM EDGE (GERAN), and the like.
[0032] In an example, the base station 114c in FIG. 1A may be a
wireless router, Home Node B, Home eNode B, or access point, for
example, and may utilize any suitable RAT for facilitating wireless
connectivity in a localized area, such as a place of business, a
home, a vehicle, a campus, and the like. In one embodiment, the
base station 114c and the WTRUs 102a, 102b, and 102c may implement
a radio technology such as IEEE 802.11 to establish a wireless
local area network (WLAN). In another embodiment, the base station
114c and the WTRUs 102a, 102b, and 102c may implement a radio
technology such as IEEE 802.15 to establish a wireless personal
area network (WPAN). In yet another embodiment, the base station
114c and the WTRUs 102a, 102b, and 102c may utilize a
cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.)
to establish a picocell or femtocell. Any of the base stations may
have a direct connection to the Internet 110. In the case of a
direct connection to the Internet 110, a base station may not be
required to access the Internet 110 via the core network 106.
[0033] The core network 106 may serve as a gateway for the WTRUs
102a, 102b, and 102c to access the PSTN 108, the Internet 110,
and/or other networks 112. The PSTN 108 may include
circuit-switched telephone networks that provide plain old
telephone service (POTS). The Internet 110 may include a global
system of interconnected computer networks and devices that use
common communication protocols, such as the transmission control
protocol (TCP), user datagram protocol (UDP) and the internet
protocol (IP) in the TCP/IP internet protocol suite. The networks
112 may include wired or wireless communications networks owned
and/or operated by other service providers. For example, the
networks 112 may include another core network connected to one or
more RANs.
[0034] Some or all of the WTRUs 102a, 102b, and 102c in the
communications system 100 may include multi-mode capabilities,
i.e., the WTRUs 102a, 102b, and 102c may include multiple
transceivers for simultaneously communicating with different
wireless networks over different wireless links. For example, the
WTRU 102a shown in FIG. 1A may be configured to communicate with
base station 114a, 114b, and 114c which may employ a cellular-based
radio technology.
[0035] FIG. 1B is a system diagram of the example WTRU 102a shown
in FIG. 1A. As shown in FIG. 1B, the WTRU 102a may include a
processor 118, a transceiver 120, a transmit/receive element 122, a
speaker/microphone 124, a keypad 126, a display/touchpad 128,
non-removable memory 106, removable memory 132, a power source 134,
a global positioning system (GPS) chipset 136, and other
peripherals 138. It will be appreciated that the WTRU 102a may
include any sub-combination of the foregoing elements while
remaining consistent with an embodiment.
[0036] The processor 118 may be a general purpose processor, a
special purpose processor, a conventional processor, a digital
signal processor (DSP), a plurality of microprocessors, one or more
microprocessors in association with a DSP core, a controller, a
microcontroller, Application Specific Integrated Circuits (ASICs),
Field Programmable Gate Array (FPGAs) circuits, any other type of
integrated circuit (IC), a state machine, and the like. The
processor 118 may perform signal coding, data processing, power
control, input/output processing, and/or any other functionality
that enables the WTRU 102a to operate in a wireless environment.
The processor 118 may be coupled to the transceiver 120, which may
be coupled to the transmit/receive element 122. While FIG. 1B
depicts the processor 118 and the transceiver 120 as separate
components, it will be appreciated that the processor 118 and the
transceiver 120 may be integrated together in an electronic package
or chip.
[0037] The transmit/receive element 122 may be configured to
transmit signals to, or receive signals from, a base station (e.g.,
base stations 114a, 114b, and 114c) over the air interface 116. For
example, in one embodiment, the transmit/receive element 122 may be
an antenna configured to transmit and/or receive RF signals. In
another embodiment, the transmit/receive element 122 may be an
emitter/detector configured to transmit and/or receive IR, UV, or
visible light signals, for example. In yet another embodiment, the
transmit/receive element 122 may be configured to transmit and
receive both RF and light signals. It will be appreciated that the
transmit/receive element 122 may be configured to transmit and/or
receive any combination of wireless signals.
[0038] In addition, although the transmit/receive element 122 is
depicted in FIG. 1B as a single element, the WTRU 102a may include
any number of transmit/receive elements 122. In one embodiment, the
WTRU 102a may include two or more transmit/receive elements 122
(e.g., multiple antennas) for transmitting and receiving wireless
signals over the air interface 116.
[0039] The transceiver 120 may be configured to modulate the
signals that are to be transmitted by the transmit/receive element
122 and to demodulate the signals that are received by the
transmit/receive element 122. As noted above, the WTRU 102a may
have multi-mode capabilities. Thus, the transceiver 120 may include
multiple transceivers for enabling the WTRU 102a to communicate via
multiple RATs, such as UTRA and IEEE 802.11, for example.
[0040] The processor 118 of the WTRU 102a may be coupled to, and
may receive user input data from, the speaker/microphone 124, the
keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal
display (LCD) display unit or organic light-emitting diode (OLED)
display unit). The processor 118 may also output user data to the
speaker/microphone 124, the keypad 126, and/or the display/touchpad
128. In addition, the processor 118 may access information from,
and store data in, any type of suitable memory, such as the
non-removable memory 106 and/or the removable memory 132. The
non-removable memory 106 may include random-access memory (RAM),
read-only memory (ROM), a hard disk, or any other type of memory
storage device. The removable memory 132 may include a subscriber
identity module (SIM) card, a memory stick, a secure digital (SD)
memory card, and the like. In other embodiments, the processor 118
may access information from, and store data in, memory that is not
physically located on the WTRU 102a, such as on a server or a home
computer (not shown).
[0041] The processor 118 may receive power from the power source
134, and may be configured to distribute and/or control the power
to the other components in the WTRU 102a. The power source 134 may
be any suitable device for powering the WTRU 102a. For example, the
power source 134 may include one or more dry cell batteries (e.g.,
nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride
(NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and
the like.
[0042] The processor 118 may also be coupled to the GPS chipset
136, which may be configured to provide location information (e.g.,
longitude and latitude) regarding the current location of the WTRU
102a. In addition to, or in lieu of, the information from the GPS
chipset 136, the WTRU 102a may receive location information over
the air interface 116 from a base station (e.g., base stations
114a, 114b, and 114c) and/or determine its location based on the
timing of the signals being received from two or more nearby base
stations. It will be appreciated that the WTRU 102a may acquire
location information by way of any suitable location-determination
method while remaining consistent with an embodiment.
[0043] The processor 118 may further be coupled to other
peripherals 138, which may include one or more software and/or
hardware modules that provide additional features, functionality
and/or wired or wireless connectivity. For example, the peripherals
138 may include an accelerometer, an e-compass, a satellite
transceiver, a digital camera (for photographs or video), a
universal serial bus (USB) port, a vibration device, a television
transceiver, a hands free headset, a BLUETOOTH.RTM. module, a
frequency modulated (FM) radio unit, a digital music player, a
media player, a video game player module, an Internet browser, and
the like.
[0044] In accordance with embodiments of the present disclosure,
non-orthogonal dimensionality between multiple interfering signals
is exploited. As referred to herein, "dimensionality" may refer to
any differences between the multiple interfering signals that are
able to be exploited by the receiver in order to aid the decoding
process. This is in contrast to conventional methods that attempt
to orthogonalize multiple signals in time, frequency, spreading
code, or space so they do not interfere.
The present disclosure instead is directed to cases where the
interfering signals either cannot be orthogonal or orthogonality is
not desirable from a system design perspective. Instead the
dimensionality between the signals occurs so as that they are not
orthogonal but instead to exploit the receiver which is able to
separate signals partially or fully through the created dimensions.
Accordingly, adding a level of non-orthogonal dimensionality
between signals as used herein is said to "differentiate" one
signal from another. Similarly, when any of the terms
"differentiate," differentiates," or "differentiated" is used with
respect to signals, it is intended to refer to an increase in
non-orthogonal dimensionality between signals. When there is
greater dimensionality between two or more interfering signals,
receivers designed to process interfering signals perform with
increased accuracy and speed.
[0045] Receivers with MUD capabilities benefit from greater
non-orthogonal dimensionality between two or more interfering
signals, since MUD is a receiver design technology for detecting
desired signal(s) from interference and noise. MUD works by
exploiting dimensionality between multiple interfering signals. The
dimensionality may occur naturally between interfering signals but
may also, as an aspect of the subject matter described herein, be
purposely introduced in order to create advantageous situations for
the MUD. The dimensionality can take the form of any difference
between the received signals that can be exploited by the MUD to
more reliably decode the interfering signals. As an aspect of the
subject matter described herein, power, symbol phase, and timing of
an interfering transmitter or transmitters can be adjusted in order
to improve MUD performances in decoding the interfering signals. In
many instances, where there is a lack of or sub-optimal
dimensionality between the multiple interfering signals received by
the MUD receiver, and as an aspect of the subject matter described
herein, better MUD receiver performance may be obtained by
introducing dimensionality between the interfering signals.
[0046] Multiple-input and multiple-output (MIMO) decoding
techniques also benefit from greater non-orthogonal dimensionality
between two or more interfering signals. Generally speaking, MIMO
involves the use of multiple antennas at both the transmitter and
receiver to improve communication performance through significant
increases in data throughput and link range without additional
bandwidth or increased transmit power. It achieves this goal by
spreading the same total transmit power over the antennas to
achieve an array gain that improves the spectral efficiency and/or
to achieve a diversity gain that improves the link reliability. As
an aspect of the subject matter described herein, power, symbol
phase, and timing of an interfering transmitter or transmitters can
be adjusted in order to improve MIMO performances in decoding the
interfering signals. In many instances, where there is a lack of or
sub-optimal dimensionality between the multiple interfering signals
received by the MIMO receiver, and as an aspect of the subject
matter described herein, better MIMO receiver performance may be
obtained by introducing dimensionality between the interfering
signals.
[0047] As a conceptual example of adding non-orthogonal
dimensionality between signals, a particular receiver may receive
two data streams that have no dimensionality between those signals.
No dimensionality implies that there is a single antenna, no power
offset, symbol phase offset, coding, or the like as depicted in
FIG. 2. FIG. 2 depicts two BPSK users' constellations as seen by a
receiver as well as the superposition of those constellations,
which occurs in the receiver's antenna. Since there is no
dimensionality between the signals, the two users cannot be decoded
even for an optimal receiver. When dimensionality is added, as
shown in FIG. 3, both signals can now be decoded at the receiver.
FIG. 3 depicts user two's power being reduced to add the
dimensionality.
[0048] The phase of the received signals additionally can be used
to create dimensionality between the signals by inducing a phase
offset between the received signals. FIG. 4 depicts a scenario that
uses phase offset in a symbol synchronous case as dimensionality
between the signals. In this case, a phase offset of one or both
users' constellations such that they arrive at the receiver with a
90 degree offset, hence making it easier to decode. It is noted
that a 90 degree offset may not always be optimal depending on the
modulation scheme, the number of received signals, or another
number of other factors. For example, if each signal, of two
signals, is a QPSK modulated signal, then a 45 degree offset may be
more appropriate.
[0049] Another example form of dimensionality that a receiver can
utilize is symbol asynchrony. Symbol asynchrony can be induced by
instructing certain transmitters to transmit with a time
adjustment. This control is already in place in many existing
networks. Note that in a symbol synchronous network, some level of
symbol asynchrony would be purposely introduced.
[0050] In another example, scheduling may also be used to create
the desired dimensionality in power and phase between the multiple
data streams in order to aid the decoding process. In particular,
signals may be purposely scheduled to interfere with each other on
a particular frequency because their phase and power parameters
already have dimensionality between them--doing such makes capacity
available on other frequencies. Due to the ability to select from
many data streams and the natural variations in received power and
phase offsets that occur due to channel fading, users can be
scheduled in a manner so that there is sufficient power and phase
separation between interfering signals. The fading phenomenon is
especially prevalent in narrowband communication systems or
wideband communication systems that subdivide its bandwidth such as
OFDM, OFDMA, SC-FDMA and any other "subbanded" systems.
[0051] In accordance with embodiments of the present disclosure,
two or more available dimensions may be jointly optimized. An
increased level of performance can be obtained by attempting to
force power and phase separations, as well as other factors that
affect the level of performance. These other factors include but
are not limited to the channel, modulation rate, and coding
rate.
Maximization of performance is dependent on many factors and
changes depending on, for example, the MUD technique used.
[0052] An example use of the presently disclosed subject matter is
to increase performance in group detection techniques. Group
detection algorithms decrease the complexity of the receiver by
grouping users so that the decoder can operate on fewer than all of
the data streams at a time. There are various grouping techniques
from the easiest which is to arbitrary pick a certain number of
streams to more complicated techniques such as minimizing the error
vector magnitude using a linear detector. Having the data streams
arrive at the receiver with different power levels aids the
grouping process. Note that depending on the grouping technique
chosen; separating the users in power does not necessarily amount
to power ordering of users. Hence, the solution that maximizes the
performance may not be simply power ordering. As previously
mentioned the optimal grouping will include a combination of other
factors and the decoding technique. Hence, specific data streams
may be directed to change power level based partly on other
factors, such as spatial correlation, modulation, coding, spreading
length, etc.
[0053] Various embodiments of using dimensionality to increase
decoding performance are disclosed below. Note that each of these
techniques may involve attempting to control the received power at
a specific instant in time or averaged over some time; attempting
to separate the power and/or phase of groups of users, i.e., a
grouping of user signals arrive spaced within a set power range;
attempting to linearly space the power of users; and attempting to
exponentially space the power of users.
[0054] In accordance with embodiments of the present disclosure,
group detection may be used as an intra-cell and inter-cell
decoder. An example case of the group detection is to group users
with knowledge of which cells they belong to as a method of
grouping. In this case, explicit knowledge of the received
powers/phases may not be available, especially in the case of data
streams from other cells.
[0055] The best phase offset mechanism depends heavily on elements
of the system/scenario. In this case, here "spacing in phase" does
not necessarily refer to 0 to 360 degrees, instead it refers to
between two unspecified [angle] values. Specific uses of phase
dimensionality that are imposed to aid the detector may be: linear
spacing in phase; logarithmic or exponential spacing in phase; and
purposely causing phase rotation on the transmitter to provide a
uniform distribution of phase offset amongst the various
signals.
[0056] Another example use of the presently disclosed subject
matter is for non-hub and spoke networks. In this case, the
scheduling and power/phase control must be acceptable at multiple
different receivers. The scheduling and power/phase control may be
determined at multiple different locations or in a centralized
fashion. Scheduling and power/phase control may arrive from
multiple different sources from multiple different directions and
with different measurements, such as the case in ad hoc networks or
with adjacent cells.
[0057] Another use of the presently disclosed subject matter is to
use the information from the decoding process to continue to
iterate on the parameters rather than from a module built
specifically for parameter estimation. This may be in the form of
blindly trying to adjust parameters until they are successful or
using specific measurements out of the decoder to intelligently
adjust the parameters.
[0058] Dimensionality may be physically accomplished through
feedback from one or more receivers. The receiver may estimate the
parameters of the received signals, determine an adjustment in
parameters of one or more of the received signals that would result
in greater dimensionality between the received signals, and feed
the parameter adjustments back to the transmitters, using whatever
feedback mechanism is in place. The parameter estimates can take
place anywhere in the receiver but are typically from a parameter
estimation module or are an output of the decoding process in the
detector. As previously mentioned, many networks have mechanisms to
adjust the amplitude and/or phase of the transmissions but do so
for other reasons. In these networks, that algorithm in the
receiver that controls the amplitude and/or phase of the
transmitted signal would be modified to include optimizing the
dimensionality for the multi-user detector. A joint optimization is
likely to be performed that balances the needs of multiple goals.
As an example, an optimization of power may be a balance of
adjusting the power of the transmitters, as received by the
receiver, to be diverse so as to increase the MUD performance, but
to not be too diverse (and in particular, so as not to be
transmitting with too high of a power level) such that the
transmissions are negatively impacting adjacent cells through
intercell interference. All of the control and decision making for
the feedback may also originate from higher level logic devices
that are possibly removed from the physical receiver.
[0059] In an example, in a cellular network where various terminals
communicate to a base station, that base station may have a MUD
receiver based on grouping users, i.e., the MUD does not jointly
decode all users, but rather groups them first and jointly decodes
those users. This method is typically used to reduce the complexity
of the receiver. Suppose further that the MUD with grouping
performs better when all users in a particular group transmit at a
power within a set power range but that power range is separated
from the power ranges from other groups. For the sake of example
and without the loss the generality, suppose a MUD is used that
groups users into groups of 2 and that the error is minimized when
the groups have powers separated by 3 dB. The base station measures
the power through a parameter estimation module and continuously
adjusts the power of at least one of the terminals so that it
arrives at the desired power. It is noted that the performance of
the hypothetical group MUD may depend on all dimensions rather than
just power and therefore must be taken into account to maximize
performance.
[0060] Many MUDs also perform best with phase dimensionality
between the received signals. Using the same example of a base
station and terminals, the base station may attempt to only
schedule users with acceptable symbol phase offsets. Additionally,
it may instruct the terminals to induce a symbol phase offset or
time delay to induce symbol asynchrony upon transmission.
[0061] In accordance with this embodiment, MUD based detectors
within a cellular network may be aided. Most modern cellular
networks use power control to attempt to force all users to arrive
at the base station at the same power. As an aspect of the subject
matter described herein, the cellular network may instruct
transmitters to transmit at differing power levels (as received by
the base station receiver), hence aiding with MUD without having
significant impact to the network. In an example, the power of the
users may be linearly separated in dB or whatever is optimal for
the particular MUD algorithm. The decision to schedule users may be
determined through a combination of power levels and other
dimensionality factors.
[0062] In an exemplary embodiment illustrated by FIG. 5, a receiver
of a cellular network system receives transmissions from two or
more transmitters, where the transmitters are both transmitting to
the receiver (that is, they are "in" the receiver's cell) and the
transmitters are transmitting simultaneously on the same frequency
or channel (step 500). The receiver, using its MUD capabilities,
detects the transmissions from the transmitters and conducts
parameter estimation on the transmissions (step 502). The receiver
may analyze the parameter estimations of the transmissions and
determine that certain transmission parameters (e.g., power levels
and phase) of certain transmitters, if adjusted, could result in
more optimally spaced parameters for reception and decoding by the
receiver. In particular, by determining that adjusting a parameter
of a transmitter to be more optimally spaced from that of at least
one other transmitter, the receiver may determine that a larger
phase shift should exist between the at least two transmitters, or
that a larger difference in power levels (as received by the
receiver) should exist between the at least two transmitters. In an
embodiment, the receiver determines the parameter adjustments for
the transmitters by determining the parameters that would result in
non-orthogonal dimensionality between the signals to increase the
likelihood that the receiver will be able to separate those
signals. This determined set of parameter adjustments may only
apply to one of the transmitters, or may apply to multiple
transmitters. The receiver communicates to the transmitter(s) the
parameter adjustments to adjust the parameters (step 504). The one
or more transmitters are scheduled to transmit, and likely
continually transmit since they now are separable, with parameters
that add dimensionality to differentiate the signals that arrive at
the receiver to aid in the decoding process without making the
signals orthogonal (step 506). The parameter adjustments are
updated based on the output of the decoder or other metrics to
ensure future transmissions are also separable (step 508). The
receiver communicates to the transmitter(s) instructions to
implement the updated adjustments for future transmissions (step
504). In an embodiment, a greater dimensionality that results in
improved MUD performance is sought, but not at the cost of
intercell interference at adjacent cells, nor at the cost of
requiring at least one transmitter to transmit at a power level
that strongly consumes its battery resources.
[0063] In another embodiment, the receiver may instruct certain
transmitters to transmit on alternative frequencies or channels or
time slots, and instruct alternative transmitters (that previously
were on alternative frequencies or channels or time slots) to
transmit on this particular frequency or channel or time slots
based on the parameter estimations of those transmitters.
[0064] In another embodiment, in a situation where at least one of
the transmissions is from a transmitter that is not "in" the
receiver's cell, the receiver determine which transmitters are "in"
its cell and optimizes the parameter adjustments for only those
transmitters in light of the transmission parameters of the
transmitter that is not "in" the receiver's cell.
[0065] In another embodiment, in a situation where at least one of
the transmissions is from a transmitter that is not "in" the
receiver's cell, the multiple cells may communicate with each other
to come up with a joint solution to changing the transmissions
parameters and communicate the transmission parameters through one
or more cells.
[0066] FIG. 6 illustrates a flow chart of an example method for
receiving multiple signals one or more electronic devices, such as
WTRUs, and for communicating signaling adjustment information to
one or more of the electronic devices for distinguishing the
signals in accordance with embodiments of the present subject
matter. The example method may be implemented by a suitable base
station, such as the base station 114a, configured with multi-user
detection capabilities as disclosed herein. One or more other
system components, such as the components shown in FIG. 1A, may be
used together with the base station to implement the steps of this
example method. This example is described by use of the base
station 114a; however, any suitable base station or other
electronic device operating in any suitable network may be
utilized.
[0067] In the example of FIG. 6, one or more wireless sources may
transmit to the base station 114a multiple interfering signals. For
example, WTRUs 102a and 102b may each transmit signal data on the
air interface 116 or WTRUs 102a may transmit multiple signals, such
as in a MIMO arrangement where the WTRU has multiple transmit
antennas. Examples of the signal data include video, one or more
images, any type of multimedia content, the like, any type of data,
and combinations thereof.
The signal data may be transmitted on the same or different
channels. For example, the signal data may be transmitted from the
WTRUs 102a and 102b on the same frequency and at the same time
interval.
[0068] Referring to FIG. 6, the method includes receiving signals
from at least one electronic device (step 600). For example, the
electronic device(s) may be a WTRU, user equipment (UE), a mobile
station, a fixed subscriber unit, a mobile subscriber unit, a
cellular telephone, a personal digital assistant (PDA), a
smartphone, a laptop, a netbook, a personal computer, a wireless
sensor, or a consumer device. The signals may arrive at a receiver
with the signals partially or fully overlapping in time and
frequency.
[0069] The method of FIG. 6 includes determining an adjustment of a
parameter of a received signal of a first device that would result
in an adjusted signal that is not orthogonal but differentiates the
signal from at least one other signal of the received signals (step
602). For example, the parameter of the signal may be estimated. An
adjustment may be of one or more of a symbol phase, power level,
channel, modulation rate, coding rate, timing, and the like. An
adjustment may be made such that the adjustment results in the
phase of the signal of an electronic device being different than
the phase of the signals of other electronic devices. A power level
may be adjusted such that the adjustment results in the power level
of the signal of an electronic device being different than the
power level of one or more signals of other electronic devices as
seen by the receiver.
[0070] The method of FIG. 6 includes communicating, to the first
device, an instruction to implement the adjustment of the parameter
(step 604). For example, the base station 114a may communicate
adjustments to WTRU 102b for implementation by the WTRU 102b.
Further, the receiver may decode the signals based on a suitable
MUD technique.
[0071] FIG. 7 illustrates a flow chart of another example method
for receiving signals from different electronic devices, such as
WTRUs, and for communicating signaling adjustment information to
one or more of the electronic devices for distinguishing the
signals in accordance with embodiments of the present subject
matter. The example method may be implemented by a suitable base
station, such as the base station 114a, configured with multi-user
detection capabilities as disclosed herein. One or more other
system components, such as the components shown in FIG. 1A, may be
used together with the base station to implement the steps of this
example method. This example is described by use of the base
station 114a; however, any suitable base station or other
electronic device operating in any suitable network may be
utilized.
[0072] In the example of FIG. 7, different wireless sources may
transmit to the base station 114a multiple interfering signals. For
example, WTRUs 102a and 102b may each transmit signal data on the
air interface 116. Examples of the signal data include video, one
or more images, any type of multimedia content, the like, any type
of data, and combinations thereof. The signal data may be
transmitted on the same or different channels. For example, the
signal data may be transmitted from the WTRUs 102a and 102b on the
same frequency and at the same time interval.
[0073] Referring to FIG. 7, the method includes receiving signals
from at least one electronic device (step 700). For example, the
signals may arrive at a receiver with the signals partially or
fully overlapping in time and frequency.
[0074] The method of FIG. 7 includes determining an adjustment of a
symbol phase of a received signal of a first device that would
result in an adjusted signal that is not orthogonal but
differentiates the signal from at least one other signal of the
received signals (step 702). In addition, an adjustment may also be
determined for one or more of a power level, channel, modulation
rate, coding rate, timing, and the like. An adjustment may be made
such that the adjustment results in the phase of the signal of an
electronic device being different than the phase of the signals of
other electronic devices. A symbol phase and/or other parameter may
be adjusted such that the adjustment results in the symbol phase
and/or other parameter of the signal of an electronic device being
different than the parameter of one or more signals of other
electronic devices as seen by the receiver.
[0075] The method of FIG. 7 includes communicating, to the first
device, an instruction to implement the adjustment of the symbol
phase (step 704). For example, the base station 114a may
communicate adjustments to WTRU 102b for implementation by the WTRU
102b. Further, the receiver may decode the signals based on a
suitable MUD technique.
[0076] Similar to the method described with respect to FIGS. 6 and
7, in an example the adjustment may be determined based on one or
both of a symbol phase and a power of a signal of one or more
electronic devices for use in differentiating received signals. An
instruction can be provided to one or more of the electronic
devices for adjustment of the signals such that the signals can be
differentiated.
[0077] FIG. 8 illustrates a flow chart of another example method
for receiving signals from different electronic devices, such as
WTRUs, and for communicating signaling adjustment information to
one or more of the electronic devices for distinguishing the
signals in accordance with embodiments of the present subject
matter. The example method may be implemented by a suitable base
station, such as the base station 114a, configured with multi-user
detection capabilities as disclosed herein. One or more other
system components, such as the components shown in FIG. 1A, may be
used together with the base station to implement the steps of this
example method. This example is described by use of the base
station 114a; however, any suitable base station or other
electronic device operating in any suitable network may be
utilized.
[0078] The method of FIG. 8 includes receiving a first set of
signals from a plurality of electronic devices (step 800). The
signals are transmitted at the same time and on substantially the
same frequency or an overlapping frequency.
[0079] The method of FIG. 8 includes receiving a second set of
signals from a plurality of electronic devices (step 802). The
signals are transmitted on a different frequency than the first set
of signals.
[0080] Further, the method of FIG. 8 includes estimating the
parameters of one or more of the signals of the first set of
signals (step 804). The method also includes estimating the
parameters of one or more of the signals of the second set of
signals (step 804). A receiver may determine whether one or more
parameters of a signal from the first set of signals is more
diverse with those of the second set of signals than with those of
the first set of signals. In response to determining that it is
more diverse, the electronic device transmitting the signal may be
communicated that instructs the electronic device to transmit on
the frequency of the second set of signals.
[0081] The subject matter described herein may be implemented in
alternative wireless environments besides cellular environments,
including ad hoc networks, mesh networks, and alternative
hub-and-spoke type networks. These alternative wireless networks,
as examples, could include 802.11 networks, Bluetooth networks,
Zigbee networks, Satellite communication networks, and many
others.
[0082] Further, it will be appreciated that the various techniques
described herein may also be applied to wired environments instead
of wireless environments. As an example, the techniques described
herein may be applied to cable networks, where the base-station
described herein is the head-end or an optical node, and where the
WTRUs are terminal units on the cable network such as cable-modems.
In such an embodiment, multiple cable modems would be permitted, if
not instructed, to transmit signals on interfering frequencies on
the cable network to the node or head-end (whichever the case may
be). It should be appreciated that a WTRU may receive transmissions
on a different type of network than on which it transmits on, and
as such the `Transmit` and `Receive` aspects of the WTRU may be
distinct components of the WTRU rather than a single transceiver.
For example, a WTRU may receive parameter adjustment instructions
on its 802.11 receiver for adjusting transmission parameters of its
cellular transmitter.
[0083] The various techniques described herein may be implemented
with hardware or software or, where appropriate, with a combination
of both. Thus, the methods and apparatus of the disclosed
embodiments, or certain aspects or portions thereof, may take the
form of program code (i.e., instructions) embodied in tangible
media, such as floppy diskettes, CD-ROMs, hard drives, or any other
machine-readable storage medium, wherein, when the program code is
loaded into and executed by a machine, such as a computer, the
machine becomes an apparatus for practicing the presently disclosed
subject matter. In the case of program code execution on
programmable computers, the computer will generally include a
processor, a storage medium readable by the processor (including
volatile and non-volatile memory and/or storage elements), at least
one input device and at least one output device. One or more
programs may be implemented in a high level procedural or object
oriented programming language to communicate with a computer
system. However, the program(s) can be implemented in assembly or
machine language, if desired. In any case, the language may be a
compiled or interpreted language, and combined with hardware
implementations.
[0084] The described methods and apparatus may also be embodied in
the form of program code that is transmitted over some transmission
medium, such as over electrical wiring or cabling, through fiber
optics, or via any other form of transmission, wherein, when the
program code is received and loaded into and executed by a machine,
such as an EPROM, a gate array, a programmable logic device (PLD),
a client computer, a video recorder or the like, the machine
becomes an apparatus for practicing the presently disclosed subject
matter. When implemented on a general-purpose processor, the
program code combines with the processor to provide a unique
apparatus that operates to perform the processing of the presently
disclosed subject matter.
[0085] Features from one embodiment or aspect may be combined with
features from any other embodiment or aspect in any appropriate
combination. For example, any individual or collective features of
method aspects or embodiments may be applied to apparatus, system,
product, or component aspects of embodiments and vice versa.
[0086] Although features and elements are described above in
particular combinations, one of ordinary skill in the art will
appreciate that each feature or element can be used alone or in any
combination with the other features and elements. In addition, the
methods described herein may be implemented in a computer program,
software, or firmware incorporated in a computer-readable medium
for execution by a computer or processor. Examples of
computer-readable media include electronic signals (transmitted
over wired or wireless connections) and computer-readable storage
media. Examples of computer-readable storage media include, but are
not limited to, a read only memory (ROM), a random access memory
(RAM), a register, cache memory, semiconductor memory devices,
magnetic media such as internal hard disks and removable disks,
magneto-optical media, and optical media such as CD-ROM disks, and
digital versatile disks (DVDs). A processor in association with
software may be used to implement a radio frequency transceiver for
use in a WTRU, UE, terminal, base station, RNC, or any host
computer.
[0087] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the subject matter
(particularly in the context of the following claims) are to be
construed to cover both the singular and the plural, unless
otherwise indicated herein or clearly contradicted by context.
Recitation of ranges of values herein are merely intended to serve
as a shorthand method of referring individually to each separate
value falling within the range, unless otherwise indicated herein,
and each separate value is incorporated into the specification as
if it were individually recited herein. Furthermore, the foregoing
description is for the purpose of illustration only, and not for
the purpose of limitation, as the scope of protection sought is
defined by the claims as set forth hereinafter together with any
equivalents thereof entitled to. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein, is
intended merely to better illustrate the subject matter and does
not pose a limitation on the scope of the subject matter unless
otherwise claimed. The use of the term "based on" and other like
phrases indicating a condition for bringing about a result, both in
the claims and in the written description, is not intended to
foreclose any other conditions that bring about that result. No
language in the specification should be construed as indicating any
non-claimed element as essential to the practice of the invention
as claimed.
[0088] Preferred embodiments are described herein, including the
best mode known to the inventor for carrying out the claimed
subject matter. One of ordinary skill in the art should appreciate
after learning the teachings related to the claimed subject matter
contained in the foregoing description that variations of those
preferred embodiments may become apparent to those of ordinary
skill in the art upon reading the foregoing description. The
inventor intends that the claimed subject matter may be practiced
otherwise than as specifically described herein. Accordingly, this
claimed subject matter includes all modifications and equivalents
of the subject matter recited in the claims appended hereto as
permitted by applicable law. Moreover, any combination of the
above-described elements in all possible variations thereof is
encompassed unless otherwise indicated herein or otherwise clearly
contradicted by context.
* * * * *