U.S. patent application number 14/943946 was filed with the patent office on 2017-05-18 for system and method for multi-source channel estimation.
The applicant listed for this patent is Futurewei Technologies, Inc.. Invention is credited to Arkady Molev Shteiman, Xiao Feng Qi.
Application Number | 20170141935 14/943946 |
Document ID | / |
Family ID | 58670628 |
Filed Date | 2017-05-18 |
United States Patent
Application |
20170141935 |
Kind Code |
A1 |
Molev Shteiman; Arkady ; et
al. |
May 18, 2017 |
System and Method for Multi-Source Channel Estimation
Abstract
A method for associating signal sources and paths includes
determining secondary paths of a signal received at a reception
point, wherein the signal reflects off one or more reflective
surfaces before being received at the reception point, determining
mirror sources of the secondary paths in accordance with locations
of the one or more reflective surfaces and a main source of the
signal, determining associations between the secondary paths and
the mirror sources based on cross points at which the signal
reflected off the one or more reflective surfaces, thereby
obtaining path-source associations, and instructing use of the
path-source associations in multi-source channel estimation.
Inventors: |
Molev Shteiman; Arkady;
(Bridgewater, NJ) ; Qi; Xiao Feng; (Westfield,
NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Futurewei Technologies, Inc. |
Plano |
TX |
US |
|
|
Family ID: |
58670628 |
Appl. No.: |
14/943946 |
Filed: |
November 17, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04B 7/0413 20130101;
H04L 25/024 20130101; H04L 25/0212 20130101; H04L 25/0204 20130101;
H04L 25/0224 20130101 |
International
Class: |
H04L 25/02 20060101
H04L025/02; H04B 7/04 20060101 H04B007/04 |
Claims
1. A method for associating signal sources and paths, the method
comprising: receiving radio frequency (RF) beams transmitted over
secondary paths by an antenna of a reception point, wherein the RF
beams reflect off one or more reflective surfaces before being
received at the reception point; determining locations of mirror
sources of the secondary paths in accordance with locations of the
one or more reflective surfaces and a main source of the RF beams;
determining associations between the secondary paths and the mirror
sources based on cross points at which the RF beams reflected off
the one or more reflective surfaces, thereby obtaining path-source
associations; and instructing use of the path-source associations
for multi-source channel estimation.
2. The method of claim 1, wherein determining the associations
between the secondary paths and the mirror sources based on the
cross points at which the beams reflected off the one or more
reflective surfaces comprises: tracing a first one of the secondary
paths from the main source to the reception point in accordance
with locations of the main source and the mirror sources;
determining that a first secondary path intersects at a first cross
point on the one or more reflective surfaces; determining that a
first mirror source aligns with the first cross point; and
associating the first mirror source with the first secondary
path.
3. The method of claim 1, wherein determining the associations
between the secondary paths and the mirror sources based on the
cross points at which the RF beams reflected off the one or more
reflective surfaces comprises: tracing a first beam of the RF beams
from the main source to the reception point in accordance with
locations of the main source and the mirror sources; determining
that the first beam intersects at a first cross point on the one or
more reflective surfaces; determining that a first mirror source
aligns with the first cross point; and associating the first mirror
source with a secondary path corresponding to the first beam.
4. The method of claim 1, wherein instructing the use of the
path-source associations comprises sending the path-source
associations to the reception point, the path-source associations
being used to perform the multi-source channel estimation at the
reception point for transmissions from wireless devices at or near
the main source.
5. The method of claim 1, wherein instructing the use of the
path-source associations comprises performing the multi-source
channel estimation on transmissions from wireless devices at or
near the main source.
6. The method of claim 5, wherein performing the multi-source
channel estimation comprises: determining a channel impulse
response by summing contributions from non-negligible main and
mirror sources visible to the reception point.
7. The method of claim 6, wherein the channel impulse response is
expressible as H ( .omega. ) = n = 0 N - 1 G n ( 2 D n .omega. c )
2 exp ( j D n .omega. c ) ##EQU00006## where H(.omega.) is the
channel impulse response, n is a source index (n=0, 1, 2, . . . ,
N-1) of sources that are sources visible to the reception point,
and n=0 is the main source, D.sub.n is a distance between the
reception point and source n, G.sub.n is an energy of source n.
8. The method of claim 6, wherein performing the multi-source
channel estimation further comprises: selecting sources from a set
comprising the main source and the mirror sources with energy
levels exceeding a threshold energy level.
9. The method of claim 1, further comprising storing the
path-source associations in a database.
10. The method of claim 1, further comprising: retrieving location
information about the main source and the mirror sources from a
database; and determining missing information regarding the main
source and the mirror sources in accordance with the retrieved
location information.
11. The method of claim 10, wherein the location information
further comprises locations of the one or more reflective
surfaces.
12. A device adapted to associate signal sources and paths, the
device comprising: a processor; and a non-transitory computer
readable storage medium storing programming for execution by the
processor, the programming including instructions configuring the
device to: receive radio frequency (RF) beams transmitted over
secondary paths by an antenna of a reception point, wherein the RF
beams reflect off one or more reflective surfaces before being
received at the reception point, determine locations of mirror
sources of the secondary paths in accordance with locations of the
one or more reflective surfaces and a main source of the RF beams,
determine associations between the secondary paths and the mirror
sources based on cross points at which the RF beams reflected off
the one or more reflective surfaces, thereby obtaining path-source
associations, and instruct use of the path-source associations for
multi-source channel estimation.
13. The device of claim 12, wherein the programming includes
instructions to trace a first secondary path from the main source
to the reception point in accordance with locations of the main
source and the mirror sources, to determine that the first
secondary path intersects at a first cross point on the one or more
reflective surfaces, to determine that a first mirror source aligns
with the first cross point, and to associate the first mirror
source with the first secondary path.
14. The device of claim 12, wherein the programming includes
instructions to trace a first beam of the RF beams from the main
source to the reception point in accordance with locations of the
main source and the mirror sources, to determine that the first
beam intersects at a first cross point on the one or more
reflective surfaces, to determine that a first mirror source aligns
with the first cross point, and to associate the first mirror
source with a secondary path corresponding to the first beam.
15. The device of claim 12, wherein the programming includes
instructions to send the path-source associations to the reception
point, the path-source associations being used to perform the
multi-source channel estimation at the reception point for
transmissions from wireless devices at or near the main source.
16. The device of claim 15, wherein the device is an associating
device.
17. The device of claim 12, wherein the programming includes
instructions to perform the multi-source channel estimation on
transmissions from wireless devices at or near the main source.
18. The device of claim 17, wherein the device is the reception
point.
19. The device of claim 12, wherein the programming includes
instructions to retrieve location information about the main source
and the mirror sources from a database, and to determine missing
information regarding the main source and the mirror sources in
accordance with the retrieved location information.
20. A multiple input multiple output (MIMO) communications system
comprising: a main transmission point; a MIMO communications device
including an antenna array comprising a plurality of antenna units,
and a first processor; and an associating device including a second
processor, and a non-transitory computer readable storage medium
storing programming for execution by the second processor, the
programming including instructions configuring the associating
device to receive radio frequency (RF) beams transmitted over
secondary paths by an antenna of a reception point, wherein the RF
beams reflect off one or more reflective surfaces before being
received at the reception point, determine locations of mirror
sources of the secondary paths in accordance with locations of the
one or more reflective surfaces and a main source of the RF beams,
determine associations between the secondary paths and the mirror
sources based on cross points at which the RF beams reflected off
the one or more reflective surfaces, thereby obtaining path-source
associations, and instruct use of the path-source associations for
multi-source channel estimation.
21. The MIMO communications system of claim 20, further comprising
a database configured to store the path-source associations.
22. The MIMO communications system of claim 21, wherein the
database is configured to provide location information about the
main source and the mirror sources.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to digital
communications, and more particularly to a system and method for
multi-source channel estimation.
BACKGROUND
[0002] In general, multiple input multiple output (MIMO) increases
the capacity of a radio link through the use of multiple transmit
antennas and multiple receive antennas. MIMO exploits multipath
propagation to increase the capacity of the radio link. MIMO has
proven to be effective at increasing the capacity of the radio link
and has been accepted into a variety of technical standards,
including WiFi or Wireless LAN: IEEE 802.11n, and IEEE 802.11ac;
Evolved High-Speed Packet Access (HSPA+); Worldwide
Interoperability for Microwave Access (WiMAX); and Third Generation
Partnership Project (3GPP) Long Term Evolution (LTE) Advanced.
[0003] Increasing the number of transmit antennas and receive
antennas from a relatively small number (on the order of 10 or
fewer) to a significantly larger number (on the order of 100, 1000,
10000, or more) can lead to even greater increases in the capacity
of the radio link. Such MIMO communications systems are referred to
as large-scale MIMO communications systems.
[0004] Channel estimation is a complex and time intensive
operation. Under the multi-path model, channel estimation is
performed for every multi-path at each antenna and involves
individually receiving reference signals transmitted over each
multi-path. Therefore, at a MIMO communications device, such as a
large scale MIMO communications device, the number of channel
estimations can be very large. For example, in a 10000 antenna MIMO
communications device with 3 multi-paths, there will be 30000
channel estimations even for a user terminal equipped with a single
antenna.
SUMMARY OF THE DISCLOSURE
[0005] Example embodiments provide a system and method for
multi-source channel estimation.
[0006] In accordance with an example embodiment, a method for
associating signal sources and paths is provided. The method
includes determining secondary paths of a signal received at a
reception point, wherein the signal reflects off one or more
reflective surfaces before being received at the reception point,
determining mirror sources of the secondary paths in accordance
with locations of the one or more reflective surfaces and a main
source of the signal, determining associations between the
secondary paths and the mirror sources based on cross points at
which the signal reflected off the one or more reflective surfaces,
thereby obtaining path-source associations, and instructing use of
the path-source associations in multi-source channel
estimation.
[0007] In accordance with another example embodiment, a device
adapted to associate signal sources and paths is provided. The
device includes a processor, and a computer readable storage medium
storing programming for execution by the processor. The programming
including instructions configuring the device to determine
secondary paths of a signal received at a reception point, wherein
the signal reflects off one or more reflective surfaces before
being received at the reception point, to determine mirror sources
of the secondary paths in accordance with locations of the one or
more reflective surfaces and a main source of the signal, to
determine associations between the secondary paths and the mirror
sources based on cross points at which the signal reflected off the
one or more reflective surfaces, thereby obtaining path-source
associations, and to instruct use of the path-source associations
in multi-source channel estimation.
[0008] In accordance with another example embodiment, a multiple
input multiple output (MIMO) communications system is provided. The
MIMO communications system includes a main transmission point, a
MIMO communications device, and an associating device. The MIMO
communications device includes an antenna array comprising a
plurality of antenna units, and a first processor. The associating
device includes a second processor, and a computer readable storage
medium storing programming for execution by the second processor.
The programming including instructions configuring the associating
device to determine secondary paths of a signal received at a
reception point, wherein the signal reflects off one or more
reflective surfaces before being received at the reception point,
determine mirror sources of the secondary paths in accordance with
locations of the one or more reflective surfaces and a main source
of the signal, determine associations between the secondary paths
and the mirror sources based on cross points at which the signal
reflected off the one or more reflective surfaces, thereby
obtaining path-source associations, and instruct use of the
path-source associations in multi-source channel estimation.
[0009] Practice of the foregoing embodiments enables low complexity
channel estimation in a large scale MIMO communications device by
using associations between signal paths and signal sources.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present disclosure,
and the advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawing, in
which:
[0011] FIG. 1 illustrates an example communications system
highlighting MIMO reception according to example embodiments
described herein;
[0012] FIG. 2 illustrates an example communications system
highlighting MIMO transmission according to example embodiments
described herein;
[0013] FIG. 3 illustrates an example communications system
highlighting far field sources and near field sources according to
example embodiments described herein;
[0014] FIG. 4 illustrates an example communications system,
highlighting primary and secondary paths according to example
embodiments described herein;
[0015] FIG. 5 illustrates an example communications system
highlighting the modeling of a transmission following a secondary
path and reflecting off a flat surface according to example
embodiments described herein;
[0016] FIG. 6 illustrates an example communications system
highlighting the modeling of a transmission following a secondary
path and reflecting off a broken surface according to example
embodiments described herein;
[0017] FIG. 7 illustrates an example communications system
highlighting the modeling of a transmission following a secondary
path and reflecting off a curved surface according to example
embodiments described herein;
[0018] FIG. 8A illustrates an example communications system
highlighting the modeling of a transmission following a secondary
path with a blockage according to example embodiments described
herein;
[0019] FIG. 8B illustrates a two-dimensional view of a rectangular
room, highlighting the positions of main sources and mirror sources
according to example embodiments described herein;
[0020] FIG. 9 illustrates a flow diagram of example high level
operations occurring in a device determining associations between
sources (main and mirror) and paths according to example
embodiments described herein;
[0021] FIG. 10 illustrates a flow diagram of operations occurring
in a device performing channel estimation from information about
sources and paths according to example embodiments described
herein;
[0022] FIG. 11 illustrates a flow diagram of detailed operations
occurring in a device determining associations between sources
(main and mirror) and paths according to example embodiments
described herein;
[0023] FIG. 12A illustrates an example communications system,
highlighting primary and secondary paths and associated mirror
sources according to example embodiments described herein;
[0024] FIG. 12B illustrates a first example deployment of
communications system according to example embodiments described
herein;
[0025] FIG. 13 illustrates a diagram of a relationship between a
main source, a mirror source, and a reflective surface according to
example embodiments described herein;
[0026] FIG. 14 illustrates a flow diagram of example operations
occurring in a device determining missing information from
information retrieved from a database according to example
embodiments described herein;
[0027] FIG. 15 illustrates an example MIMO communications device,
highlighting the architecture of MIMO communications device
according to example embodiments described herein;
[0028] FIG. 16 illustrates an example MIMO communications system
according to example embodiments described herein;
[0029] FIG. 17 illustrates a block diagram of an embodiment
processing system for performing methods described herein; and
[0030] FIG. 18 illustrates a block diagram of a transceiver adapted
to transmit and receive signaling over a telecommunications network
according to example embodiments described herein.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0031] The operating of the current example embodiments and the
structure thereof are discussed in detail below. It should be
appreciated, however, that the present disclosure provides many
applicable inventive concepts that can be embodied in a wide
variety of specific contexts. The specific embodiments discussed
are merely illustrative of specific structures of the embodiments
and ways to operate the embodiments disclosed herein, and do not
limit the scope of the disclosure.
[0032] One embodiment relates to multi-source channel estimation.
For example, a device determines secondary paths of a signal
received at a reception point, wherein the signal reflects off one
or more reflective surfaces before being received at the reception
point, determining mirror sources of the secondary paths in
accordance with locations of the one or more reflective surfaces
and a main source of the signal, determines associations between
the secondary paths and the mirror sources based on cross points at
which the signal reflected off the one or more reflective surfaces,
thereby obtaining path-source associations, and instructs use of
the path-source associations in multi-source channel
estimation.
[0033] The embodiments will be described with respect to example
embodiments in a specific context, namely MIMO communications
systems that support beamforming with antenna arrays having a
plurality of transmit antennas and receive antennas. The
embodiments may be applied to standards compliant communications
systems, such as those that are compliant with Third Generation
Partnership Project (3GPP), IEEE 802.11, WiMAX, HSPA, and the like,
technical standards, and non-standards compliant MIMO
communications systems, that support beamforming with antenna
arrays having a plurality of transmit antennas and receive
antennas.
[0034] FIG. 1 illustrates an example communications system 100
highlighting MIMO reception. Communications system 100 includes a
MIMO base station 105 serving K users, such as user #1 120, user #2
122, and user #K 124, where K is an integer number greater than or
equal to 1. MIMO base station 105 includes M receive antennas, such
as antenna #1 110, antenna #2 112, and antenna #M 114, where M is
an integer number greater than or equal to 1. In a large scale MIMO
implementation, M may be on the order of 100s, 1000s, 10000s, or
even greater. A special case of large scale MIMO is referred to as
massive MIMO. Massive MIMO may involve an extremely large number of
antennas, 100000 or more. A base station may also be referred to as
an access point, a NodeB, an evolved NodeB (eNB), a communications
controller, and so on, while a user may also be referred to as a
mobile station, a mobile, a terminal, a subscriber, a user
equipment (UE), and so forth. MIMO base station 105 also includes a
central processing unit 130 configured to estimate signals
transmitted by the users and received by MIMO base station 105.
[0035] While it is understood that communications systems may
employ multiple base stations capable of communicating with a
number of users, only one base station, and a number of users are
illustrated for simplicity.
[0036] In communications system 100, the K users share the same
communications system resources (such as time-frequency resources).
To simplify discussion, each user is equipped with only one
antenna. However, the example embodiments presented herein are
operable with users with any number of antennas. Each of the M
receive antennas at MIMO base station 105 are equipped with its own
radio frequency (RF) hardware (such as filters, amplifiers, mixers,
modulators, demodulators, constellation mappers, constellation
demappers, and the like), analog to digital (A/D) converters,
digital to analog (D/A) converters, as well as a local processing
unit that is capable of performing a limited amount of processing.
The local processing unit, the antenna and the associated hardware
may be referred to as an antenna unit (AU). The local processing
unit is referred to herein as an AU processing unit.
[0037] Communications system 100 may be represented as a
mathematical model expressible as:
[ y 1 y 2 y M ] = [ a 1 , 1 a 1 , 2 a 1 , K a 2 , 1 a 2 , 2 a 2 , K
a M , 1 a M , 2 a M , K ] [ x 1 x 2 x K ] + [ n 1 n 2 n M ]
##EQU00001## or ##EQU00001.2## Y = A X + N , ##EQU00001.3##
where X is a transmitted symbol vector of length K in which each
element x.sub.k represents a data symbol associated with user k; Y
is a received sample vector of length M in which each element
y.sub.m, represents a sample of receive antenna m; N is a receiver
noise sample vector of length M in which each element n.sub.m
represents the noise receive on receive antenna m, it is assumed
that N is additive white Gaussian noise (AWGN); A is a channel
matrix of size M by K in which each element a.sub.m,k represents a
channel transfer function between user k and receive antenna m; K
is the number of users served by MIMO base station 105; and M is
the number of receive antennas of MIMO base station 105. In
general, a MIMO receiver has to resolve the above expression and
given the received sample vector Y, find an estimate of the
transmitted symbol vector X (denoted {circumflex over (X)}) that is
as close as possible to the transmitted symbol vector X.
[0038] FIG. 2 illustrates an example communications system 200
highlighting MIMO transmission. Communications system 200 includes
a MIMO base station 205 serving K users, such as user #1 220, user
#2 222, and user #K 224, where K is an integer number greater than
or equal to 1. MIMO base station 205 includes M transmit antennas,
such as antenna #1 210, antenna #2 212, and antenna #M 214, where M
is an integer number greater than or equal to 2. In a large scale
MIMO implementation, M may be on the order of 100s, 1000s, 10000s,
or even greater. MIMO base station 205 also includes a central
processing unit 230 configured to assist in precoding transmissions
to the K users. Central processing unit 230 is also configured to
assist in channel estimation.
[0039] Communications system 200 may be represented as a
mathematical model expressible as:
[ r 1 r 2 r K ] = [ a 1 , 1 a 1 , 2 a 1 , M a 2 , 1 a 2 , 2 a 2 , M
a K , 1 a K , 2 a K , M ] [ w 1 , 1 w 1 , 2 w 1 , K w 2 , 1 w 2 , 2
w 2 , K w M , 1 w M , 2 w M , K ] [ x 1 x 2 x K ] ##EQU00002## or
##EQU00002.2## R = A W X + N , ##EQU00002.3##
where X is a transmitted symbol vector of length K in which each
element x.sub.k represents a symbol of user k; R is a received
sampled vector of length K in which each element r.sub.k represents
a sample received by user k; N is a received noise vector of length
K in which each element n.sub.k represents noise received by user k
(it is assumed that N is AWGN); A is a channel matrix of size M by
K in which each element a.sub.m,k represents the channel transfer
function between user k and transmit antenna m; and W is a
precoding matrix of size K by M.
[0040] As discussed previously, beamforming is a signal processing
technique used for directional communications (signal transmission
and/or reception). Beamforming involves combining antenna elements
in such a way that some directions experience constructive
interference while other directions experience destructive
interference, therefore generating a communications beam in an
intended direction. Therefore, in order to utilize beamforming, a
communications device needs to obtain directional information
regarding other communications devices with which it is
communicating. From the directional information, the communications
device may be able to generate antenna coefficients to generate
communications beams directed towards the other communications
devices.
[0041] In the far field, the distance between an antenna array of a
large scale MIMO communications device and a UE are sufficiently
large (generally, the distance between the large scale MIMO
communications device and the UE is more than an order of magnitude
greater than the dimensions of the antenna array) so that
communications beams arriving at the antenna array from the UE are
considered to be parallel. However, in the near field, the
assumption of the parallel communications beams does not hold up
since the distance between the large scale MIMO communications
device and the UE is not so great.
[0042] FIG. 3 illustrates an example communications system 300
highlighting far field sources and near field sources.
Communications system 300 includes an antenna array 305 that
includes a plurality of antennas, such as antenna 307 and antenna
309. Communications system 300 also includes a far field source 310
and a near field source 315. Far field source 310 is located at
least an order of magnitude further away from antenna array 305
than the dimensions of antenna array 305, while near field source
315 is located less than an order of magnitude of the dimensions of
antenna array 305 away from antenna array 305.
[0043] Communications beams from far field source 310, such as
communications beams 312 and 314, are parallel (or substantially
parallel) as they arrive at antenna array 305. Since the
communications beams are parallel, they have the same direction of
arrival. On the other hand, communications beams from near field
source 315, such as communications beams 317 and 319, are not
parallel as they arrive at antenna array 305. Hence the directions
of arrival of the communications beams from near field source 315
are different.
[0044] When a transmission is made from a transmission point (e.g.,
an AP in a downlink transmission or a UE in an uplink transmission)
to a reception point (e.g., the UE in the downlink transmission or
the AP in the uplink transmission), the transmission may take a
primary path from the transmission point to the reception point.
However, if there are objects in the vicinity of the transmission
point and the reception point, the transmission may reflect off
these objects and take secondary paths from the transmission point
to the reception point. In general, a primary path is a direct path
between a transmission point and a reception point. There are also
secondary paths that involve the transmission reflecting off one or
more surfaces after leaving the transmission point before arriving
at the reception point. The transmissions taking the primary and
secondary paths to the reception point may be referred to as
multipath. The transmissions taking the secondary paths have
greater delay than the transmissions taking the primary path due to
the longer path. The transmissions on the secondary paths may be
exploited to improve communications performance or they may be
interference and degrade performance. Each of the paths (primary
and secondary) may be modeled by using channel estimation
techniques. However, when the reception point has a large scale
MIMO antenna array, channel estimation may be computationally
intensive since channel estimation is performed at each antenna for
each path (primary and secondary).
[0045] FIG. 4 illustrates an example communications system 400,
highlighting primary and secondary paths. Communications system 400
includes communicating devices, UE 405 and AP 410. As shown in FIG.
4, UE 405 is making an uplink transmission to AP 410. In other
words, UE 405 is the transmission point and AP 410 is the reception
point. Communications system 400 is deployed in between a first
wall 415 and a second wall 417. As an example, communications
system 400 is deployed indoors.
[0046] When UE 405 sends a transmission to AP 410, the transmission
may follow a primary path 420. The transmission may also follow
several secondary paths, such as first secondary path 425 where the
transmission reflects off first wall 415 before arriving at AP 410,
or a second secondary path 430 where the transmission reflects off
second wall 417 and first wall 415 before arriving at AP 410. In
general, when there are more objects in the vicinity of the
communicating devices, the more paths there are between the
communicating devices. However, depending on the type of objects
involved, significant power is lost at each reflection. Therefore
transmissions over paths comprising more than three or four
reflections may be so low in power that they may not be significant
and it is possible to ignore them.
[0047] According to an example embodiment, transmissions taking
secondary paths are modeled as originating at mirror sources
instead of originating at their main source and reflecting off
intermediary objects. A transmission following a secondary path
that includes one or more reflections may be modeled as originating
at a mirror source and following a primary path rather than
originating at the main source and following the secondary
path.
[0048] FIG. 5 illustrates an example communications system 500
highlighting the modeling of a transmission following a secondary
path and reflecting off a flat surface. In communications system
500, a transmission originates at main source 505 and reflects off
reflective surface 510 towards a destination 515. A range of
transmissions 520 reflects off reflective surface 510 while
maintaining an orientation towards destination 515. It is possible
to model the transmissions reflecting off reflective surface 510 as
originating at a mirror source 525. Transmissions from mirror
source 525 pass through reflective surface 510 on towards
destination 515. A radiation sector 530 corresponds to a range of
transmission angles that correspond to range of transmissions 520.
As shown in FIG. 5, secondary paths due to reflective surface 510
may be modeled as mirror source 525 that is symmetrical to main
source 505 with respect to reflective surface 510. As the size of
reflective surface 515 increases, the likelihood that multiple
destinations will receive transmissions from mirror source 525 also
increases.
[0049] FIG. 6 illustrates an example communications system 600
highlighting the modeling of a transmission following a secondary
path and reflecting off a broken surface. In communications system
600, a transmission originates at main source 605 and reflects off
reflective surface 610. It is possible to model the transmissions
reflecting off reflective surface 610 as originating at one of a
plurality of mirror sources depending upon where on reflective
surface 610 the transmission reflects. As an illustrative example,
a transmission reflecting off a first sub-surface 612 may be
modeled as originating at mirror source1 615 with a corresponding
source1 radiation sector 620. Similarly, a transmission reflecting
off a second sub-surface 613 may be modeled as originating at
mirror source2 625 with a corresponding source2 radiation sector
630 and a transmission reflecting off a third sub-surface 614 may
be modeled as originating at mirror source3 635 with a
corresponding source3 radiation sector 640. Since the radiation
sectors of mirror sources arising from the broken surface tends to
be small, the likelihood that multiple destinations will receive
transmissions reflecting off from the broken surface is small.
[0050] FIG. 7 illustrates an example communications system 700
highlighting the modeling of a transmission following a secondary
path and reflecting off a curved surface. The curved surface may be
modeled as an infinite number of small flat surfaces. In
communications system 700, a transmission originates at main source
705 and reflects off reflective surface 710. It is possible to
model the transmissions reflecting off reflective surface 710 as
originating at one of a plurality of mirror sources (mirror sources
715) depending upon where on reflective surface 710 the
transmission reflects. Since reflective surface 710 is modeled as
an infinite number of small flat surfaces, the likelihood that
multiple destinations will receive transmissions reflecting off the
curved surface tends towards 0.
[0051] In general, the more flat surfaces with large surface area
are present in a deployment of a communications system, the more
mirror sources with wide radiation sectors are present, thereby
leading to high likelihood that many destinations will receive
transmissions reflecting off the flat surfaces. In a typical indoor
deployment, there are large numbers of such surfaces, including
walls, ceilings, roofs, doors, windows, screens, desks, pictures,
appliances, furniture, and so on. These surfaces may provide
multiple mirror sources that will be receivable by more
destinations. Small objects, such as pictures, mirrors, and so
forth, may add additional mirror sources while not be significantly
large to split a main source with a large radiation sector into
smaller radiation sectors.
[0052] FIG. 8A illustrates an example communications system 800
highlighting the modeling of a transmission following a secondary
path with a blockage. In communications system 800, a transmission
originates at main source 805 and reflects off reflective surface
810. On reflective surface 810 is a painting 815. Painting 815 may
not be as reflective as reflective surface 810 and may be viewed as
a blockage. It is possible to model the transmissions reflecting
off reflective surface 810 as originating at a wall mirror source
812 and transmissions reflecting off painting 815 as originating at
painting mirror source 817. Wall mirror source 812 has a radiation
sector 814 and painting mirror source 817 has radiation sector 819
and a blockage sector 821.
[0053] FIG. 8B illustrates a two-dimensional view 850 of a
rectangular room 855, highlighting the positions of main sources
and mirror sources. The two-dimensional view of rectangular room
855 may be a top-down or bottom-up view. Alternatively, if
rectangular room 855 had a ceiling and a floor formed from
radiation absorbing material, the rectangular room 855 may be
viewed as a two-dimensional room.
[0054] As shown in FIG. 8B, a main source 860 is positioned inside
rectangular room 855. Main source 855 has 4 first reflection mirror
sources, such as first reflection mirror sources 865 and 867, and 8
second reflection mirror sources, such as second reflection mirror
sources 870 and 877, and 12 third reflection mirror sources, such
as third reflection mirror sources 875 and 877.
[0055] A portion of the energy present in the electromagnetic beam
is absorbed by the reflection surface. Furthermore, there are also
propagation losses. Therefore, the energy of the mirror sources
decrease as the number of reflections increase. Eventually, the
energy of the higher order mirror sources approach zero. Hence, the
number of significant mirror sources is finite. As an illustrative
example, a number of significant mirror sources is equal the number
of mirror sources wherein an accumulation of the energy levels of
the mirror sources meets a threshold (e.g., 90%) of the total
signal energy.
[0056] According to an example embodiment, channel estimation at a
reception point is performed based on positions of main sources and
mirror sources of transmissions received by the reception point, as
well as associations between the main and/or mirror sources and
paths (primary and/or secondary paths). Channel estimation based on
the positions of main sources and mirror sources of transmissions
received by the reception point, as well as associations between
the main and/or mirror sources and paths, simplifies the channel
estimation process by eliminating a need for the reception point to
receive and process reference signals transmitted over the primary
and secondary paths of the multipath between the main source of the
transmission and each of the antennas in the antenna array of the
reception point. Therefore, the channel estimation complexity is
reduced. Additionally, the amount of information stored regarding
the estimated channels based on the positions of the main sources
and mirror sources of the transmissions is less than the amount of
information stored when channel estimation is derived from the
processing of received reference signals. Hence, the channel
estimates storage and/or communications overhead (such as when the
channel estimates are communicated) is reduced.
[0057] According to an example embodiment, the associations between
the main and/or mirror sources and paths are stored as generated in
a database that allows for subsequent retrieval so that overhead
involved in determining the associations are generally incurred
only once. As an illustrative example, a reception point determines
the locations of main and/or mirror sources and searches the
database using the locations. The reception point may be able to
retrieve associations between the main and/or mirror sources and
paths, as well as locations of reflective surfaces, absorptive
surfaces, and so on. Accessing the information stored in the
database may save the reception point significant overhead. The
database may be local or remote. The database may be accessible
wirelessly or using a wireline connection. The database may be
implemented in a standalone entity or it may be co-located with
another entity.
[0058] According to an example embodiment, the information stored
in the database is refined over time. As an illustrative example, a
reception point is located at a position that already has
information associated with it stored in the database but at a
different time and/or day or date; the reception point is still
able to make use of the information stored in the database to
simplify its computations. The reception point may also be able to
refine or enhance the quality of the information stored at the
database by supplementing the information stored at the database by
providing its own information. The multiple independently derived
versions of the information (collected and derived at different
times, days, or dates) may be combined to improve the quality of
the information stored at the database. As an illustrative example,
the multiple independently derived versions of the information may
be combined (e.g., averaged, weighted and then averaged, and so
forth). As another illustrative example, the multiple independently
derived versions of the information may be stored with different
time stamps, allowing future users to retrieve a version of the
information that most closely matches their situation (e.g., time
of day, day of week, day of month, and so on).
[0059] According to an example embodiment, the associations between
the main and/or mirror sources and paths stored in a database are
used to determine the locations of main and/or mirror sources that
are blocked. As an illustrative example, the coordinates of
reflective surfaces are retrieved from the database based on
coordinates of the main and/or mirror sources. As an illustrative
example, the location of a main source is retrieved from the
database based on known coordinates of mirror sources and
reflective surfaces.
[0060] FIG. 9 illustrates a flow diagram of example high level
operations 900 occurring in a device determining associations
between sources (main and mirror) and paths. Operations 900 may be
indicative of operations occurring in a device, such as a reception
point or a standalone device, determines associations between
sources (main and mirror) and paths.
[0061] Operations 900 begin with the device determining locations
of the main source and the mirror sources (block 905). The
locations of the main source and the mirror sources may be
determined by scanning for the locations or using analytical
methods to find the locations. Scanning involves the device using
its antennas to determine the locations of the main source and the
mirror sources. FIG. 8B illustrates an example of a rectangular
room with its main source and some mirror sources. As an
illustrative example, the device uses a fast acquisition system and
method as presented in co-assigned U.S. patent application entitled
"System and Method for Large Scale Multiple Input Multiple Output
Communications", application Ser. No. 14/867,931, filed Sep. 28,
2015, which is hereby incorporated herein by reference, to scan for
the locations of the main source and the mirror sources.
[0062] As an alternative illustrative example, the device uses an
analytical system and method to find the locations of the main
source and the mirror sources. For discussion purposes, consider a
scenario where the location of the main source is (x1, y1, z1) with
a reflective surface located at (z=Ax+By+C), where A, B, and C are
constants. It is possible to find the location of a mirror source
that is symmetric to the main source relative to the reflective
surface. First, the coordinates of a projection of the main source
onto the reflective surface is found. The coordinates of projection
(x0, y0, z0) satisfying the condition
z0=Ax0+By0+C,
which is obtained by minimizing the following expression with
respect to (x0, y0, z0)
D.sup.2=(x1-x0).sup.2+(y1-y0).sup.2+(z1-Ax0+By0+C).sup.2.
Therefore,
[0063] { .differential. D 2 .differential. x 0 = - 2 ( x 1 - x 0 )
- 2 ( z 1 - A x 0 - B y 0 - C ) A = 0 .differential. D 2
.differential. x 0 = - 2 ( y 1 - y 0 ) - 2 ( z 1 - A x 0 - B y 0 -
C ) B = 0 or { x 1 - x 0 = ( A x 0 + B y 0 + C - z 1 ) A y 1 - y 0
= ( A x 0 + B y 0 + C - z 1 ) B or { x 1 - x 0 = A A x 0 + A B y 0
+ A C - A z 1 y 1 - y 0 = B A x 0 + B B y 0 + B C - B z 1 or { x 1
= ( A 2 + 1 ) x 0 + A B y 0 + A C - A z 1 y 1 = ( B 2 + 1 ) y 0 + A
B x 0 + B C - B z 1 or { x 1 = ( A 2 + 1 ) x 0 + A B y 0 + A C - A
z 1 y 0 = y 1 - A B x 0 - B C + B z 1 ( B 2 + 1 ) or x 1 = ( A 2 +
1 ) x 0 + A B ( y 1 - A B x 0 - B C + B z 1 ( B 2 + 1 ) ) + A C - A
z 1 or x 1 = ( ( A 2 + 1 ) - ( A 2 B 2 ( B 2 + 1 ) ) ) x 0 + A B (
y 1 - B C + B z 1 ( B 2 + 1 ) ) + A C - A z 1. ##EQU00003##
[0064] The coordinates of the projection of the main source onto
the reflective surface is expressible as
x 0 = x 1 - A B ( y 1 - B C + B z 1 ( B 2 + 1 ) ) - A C + A z 1 ( (
A 2 + 1 ) - ( A 2 B 2 ( B 2 + 1 ) ) ) y 0 = y 1 - A B x 0 - B C + B
z 1 ( B 2 + 1 ) z 0 = A x 0 + B y 0 + C . ##EQU00004##
[0065] The coordinates of the mirror source (x2, y2, z2) may be
derived from the coordinates of the projection of the main source
onto the reflective surface and the coordinates of the main
source:
(x2,y2,z2)=(x0,y0,z0)+((x0,y0,z0)(x1,y1,z1))=2(x0,y0,z0)(x1,y1,z1),
hence,
x2=2x0-x1
y2=2y0-y1.
z2=2z0-z1
[0066] The device determines primary paths and secondary paths
(block 910). As discussed previously, primary paths are direct
paths from main sources to reception points, while secondary paths
are paths that include one or more reflections from main sources to
reception points. The secondary paths may be modeled as paths
without reflections (similar to primary paths but not originating
from a main source) from mirror sources to reception points.
[0067] The device traces a secondary path (block 915). The device
may trace a secondary path from a plurality of secondary paths
found in block 910. The device traces the secondary path starting
from the main source to the reception point. The device determines
if the secondary path crosses any surfaces (reflective or
otherwise) (block 920). Where the secondary path crosses a surface
is referred to as a crossing point. The determination if the
secondary path crosses any surfaces may be in accordance with
physical environmental deployment (PED) information regarding the
physical layout of the environment in which the communications
device and the main sources are deployed. The PED information may
include information about number and type (such as reflective or
absorptive properties, penetration properties, and so on) of
surfaces that reflect or absorb electromagnetic beams (such as
walls, doors, ceilings, floors, and so forth), significant objects
that reflect or absorb electromagnetic beams (such as large
furniture pieces, large appliances, large mirrors, filing cabinets,
computer servers, large televisions, and so on), less significant
objects that reflect or absorb electromagnetic beams (such as small
furniture pieces, art pieces, small appliances, small computers,
displays, small televisions, printers, scanners, copiers, and the
like), and the like. The PED information may also include
information related to an extent of signal coverage since the
extent of signal coverage has a role in determining which reception
point sees which mirror source.
[0068] The device determines mirror sources that correspond with
crossing points (block 925). A mirror source corresponds with a
crossing point if it is aligned with the crossing point and a
destination of the secondary path, which may be a reception point
or a subsequent crossing point. The device associates each mirror
source that corresponds with a crossing point with its respective
crossing point (block 930). Blocks 915, 920, 925, and 930 may be
referred to collectively as determining associations between
sources and paths (blocks 935).
[0069] The device may be a standalone device responsible for
determining paths (primary and secondary), locations of sources
(main and mirror), and so on. In such a situation, the device may
provide information about the paths and sources to a database. The
device may communicate information about the paths and sources to a
neighboring device having similar information obtained by the
aforementioned example embodiments from its own vintage point,
therefore allowing a network of devices to form a collective
picture about all the main sources and mirror sources pertaining to
the entire network. Alternatively, the device may be a standalone
device responsible for performing channel estimation. In such a
situation, the device may use information about the paths and
sources to estimate channels. The device may provide information
about the channel estimates to transmission points and reception
points, or the device may provide the information about the channel
estimates to a database. Alternatively, the device may be a
communications device, such as a reception point or a transmission
point. In such a situation, the device use information about the
paths and sources to estimate channels for its own use. The device
may also provide the information about the channel estimates to a
database.
[0070] FIG. 10 illustrates a flow diagram of operations 1000
occurring in a device performing channel estimation from
information about sources and paths. Operations 1000 may be
indicative of operations occurring in a device, such as a reception
point or a standalone device, performs channel estimation from
information about sources and paths.
[0071] Operations 1000 begin with the device determining sources
that have non-negligible energy (block 1005). As discussed
previously, when an electromagnetic beam reflects off a reflective
surface, a portion of the energy present in the electromagnetic
beam is absorbed by the reflective surface. Furthermore, there is
also propagation loss. Therefore, the energy of the mirror sources
decrease as the number of reflections increase. Eventually, the
energy of mirror sources for paths that have many reflections
(these mirror sources are referred to as higher order mirror
sources) approaches zero. Hence, the number of significant mirror
sources is finite. The device may simply specify a threshold energy
level relative to the energy level of the main source and the
mirror sources with energy levels exceeding the threshold energy
level are non-negligible while those that do not exceed the
threshold energy level are negligible. The device determines which
of the mirror sources with non-negligible energy are visible to the
reception point (block 1010). Those that are not visible to the
reception point may be removed from consideration. The device
determines a channel impulse response H(.omega.) as a sum of
sources that are visible to the reception point (block 1015). As an
illustrative example, the channel impulse response may be expressed
as
H ( .omega. ) = n = 0 N - 1 G n ( 2 D n .omega. c ) 2 exp ( j D n
.omega. c ) ##EQU00005##
where n is a source index (n=0, 1, 2, . . . , N-1) and n=0 is the
main source, D.sub.n is a distance between the reception point and
source n, G.sub.n is an energy of source n.
[0072] FIG. 11 illustrates a flow diagram of detailed operations
1100 occurring in a device determining associations between sources
(main and mirror) and paths. Operations 1100 may be indicative of
operations occurring in a device, such as a reception point or a
standalone device, determines associations between sources (main
and mirror) and paths. Operations 1100 may be a detailed view of an
example implementation of operations 900 for higher order mirror
sources (e.g., second, third, fourth, and so on, order mirror
sources).
[0073] Operations 1100 begin with the device determining locations
of main sources and mirror sources (block 1105). Determining the
locations of main sources and mirror sources may be performed by
scanning and/or analytical techniques. The device determines
primary paths and secondary paths (block 1110).
[0074] The device initializes variables (block 1115). The variables
initialized include a destination being set to the reception point.
The device selects a secondary path and a mirror source (block
1120). The device connects the mirror source to the destination
with a line (block 1125). The device performs a check to determine
if the line crosses a surface, e.g., a reflective or absorptive
surface (block 1130). If the line crosses a surface the device
determines a point wherein the line crosses the surface, which is
referred to as a cross point (block 1135). The device determines
that a line between the cross point and the destination is part of
a traced beam, thereby associating the mirror source with the
secondary path (block 1140) and sets the destination to be the
cross point (block 1145).
[0075] The device performs a check to determine if there are more
mirror sources not checked with respect to the selected secondary
path (block 1150). If there are more mirror sources not checked
with respect to the selected secondary path, the device returns to
block 1120 to select a mirror source to check with respect to the
selected secondary path. If there are no more mirror sources in the
selected secondary path, the device performs a check to determine
if there are more secondary paths (block 1155). If there are more
secondary paths, the device returns to block 1115 to reinitialize
the variables and repeat the beam tracing with another secondary
path. If there are no more secondary paths, operations 1100
terminates.
[0076] FIG. 12A illustrates an example communications system 1200,
highlighting primary and secondary paths and associated mirror
sources. Communications system 1200 includes communicating devices,
main source 1205 and an AP 1210. As shown in FIG. 12A, main source
1205 is making an uplink transmission to AP 1210. In other words,
main source 1205 is the transmission point and AP 1210 is the
reception point. Communications system 1200 is deployed in between
a first wall 1215 and a second wall 1217. As an example,
communications system 1200 is deployed indoors.
[0077] When main source 1205 sends a transmission to AP 1210, the
transmission may follow a primary path 1220. The transmission may
also follow several secondary paths, such as first secondary path
1225 where the transmission reflects off first wall 1215 before
arriving at AP 1210, or a second secondary path 1230 where the
transmission reflects off second wall 1217 and first wall 1215
before arriving at AP 1210. First secondary path 1225 reflects off
a single wall, so there is a single mirror source associated with
first secondary path 1225, which is shown in FIG. 12A as first
reflected source 1235. Second secondary path 1230 reflects off two
walls, so there are two mirror sources associated with second
secondary path 1230, which are shown in FIG. 12A as second mirror
source 1240 and third mirror source 1245.
[0078] Communications system 1200 of FIG. 12A is used to discuss
operations 1100. A first example iteration through operations 1100
may involve first secondary path 1225 and first mirror source 1235.
A line drawn from first mirror source 1235 to a destination (access
point 1210) results in cross point 1250 and a line segment between
cross point 1250 and the destination (access point 1210) being set
as part of a first traced beam. With the destination being updated
to be equal to cross point 1250, a line is drawn from main source
1205 to the destination. There are no new cross points and a line
segment from main source 1205 and the destination is being set as
part of the first traced beam. A second example iteration through
operations 1100 may involve second secondary path 1230 and second
mirror source 1245. A line drawn from second mirror source 1245 to
a destination (reset back to access point 1210) results in cross
point 1252 and a line segment between cross point 1252 and the
destination (access point 1210) being set as part of a second
traced beam. With the destination being updated to be equal to
cross point 1252, a line is drawn from third mirror source 1240 to
the destination results in cross point 1254 and a line segment from
cross point 1254 and the destination (cross point 1252) being set
as part of the second traced beam. With the destination being
updated to be equal to cross point 1254, a line is drawn from main
source 1205 to the destination. There are no new cross points and a
line segment from main source 1205 and the destination is being set
as part of the second traced beam.
[0079] FIG. 12B illustrates a first example deployment of
communications system 1260. Communications system 1260 is deployed
in an ideal rectangular shaped room with radiation absorbing
materials in the ceiling and floor of the room. A main source 1265
is deployed in the room and four access points (access point 1
1270, access point 2 1272, access point 3 1274, and access point 4
1276) are positioned along the walls of the room. Table 1 provides
information relating communications devices (APs) to main sources
and/or mirror sources in a deployment as shown in FIG. 12B, where a
"+" indicates that an AP is able to receive a signal from main
source 1265 or a mirror source and a "-" indicates that an AP is
unable to receive a signal from main source 1265 or a mirror
source. Additionally, only first reflection mirror sources are
considered. Table 1 provides an illustrative example of the
information about the paths and the sources, as stored in a
database.
TABLE-US-00001 TABLE 1 APs and sources in ideal rectangular room.
AP 1 AP 2 AP 3 AP 4 Main source + + + + Mirror Source # 1 - + + +
Mirror Source # 2 + - + + Mirror Source # 3 + + - + Mirror Source #
4 + + + -
[0080] As discussed previously, the information about the paths and
the sources, as well as the PED information, may be provided to and
stored in a database. The database may be accessible by
transmission points and/or reception points that are operating in
(or entering or exiting) an area corresponding to a span of the
information (i.e., the information about the paths and sources, as
well as the PED information) stored in the database.
[0081] FIG. 13 illustrates a diagram 1300 of a relationship between
a main source 1305, a mirror source 1310, and a reflective surface
1315. As shown in FIG. 13, there is a relationship between main
source 1305, mirror source 1310, and reflective surface 1315 that
may be described geometrically. As an illustrative example, given a
first angle 1320 between main source 1305 and reflective surface
1315, a complementary second angle 1322 exists between mirror
source 1310 and reflective surface 1315. Similarly, there is a
relationship between a first distance 1325 between main source 1305
and reflective surface 1315 and a second distance 1327 between
mirror source 1310 and reflective surface 1315. As an example, when
first angle 1320 is 90 degrees, second angle 1322 is also 90
degrees and first distance 1325 is also equal to second distance
1327.
[0082] If some of the information about the paths or the sources is
missing, it is possible to determine the missing information from
the information that is known. As an illustrative example, it is
possible to determine the location of reflective surface 1315 from
the location of main source 1305 and mirror source 1310. As another
illustrative example, it is possible to determine the location of
main source 1305 from the location of mirror source 1310 and
reflective surface 1315.
[0083] According to an example embodiment, the missing information
is determined by a device in accordance with information about the
paths and the sources, as well as the PED information retrieved
from a database. The information about the paths and the sources,
along with the PED information retrieved from the database may be
incomplete; therefore, the device has to determine the missing
information from the information available from the database.
Although the device has to determine the missing information, it
may be computationally advantageous compared to the device having
to fully derive all of the information using scanning, measuring,
and computing techniques as described herein.
[0084] FIG. 14 illustrates a flow diagram of example operations
1400 occurring in a device determining missing information from
information retrieved from a database. Operations 1400 may be
indicative of operations occurring in a device, such as a reception
point or a standalone device, determining missing information from
information retrieved from a database.
[0085] Operations 1400 begin with the device obtaining information
from a database (block 1405). The device may send a request or
query to the database and receive a message including the
information from the database. Alternatively, the device may
automatically receive a message including the information from the
database as part of mobility operation, such as an attachment
procedure, a handover, and so on. The device determines that there
is missing information (block 1410) and determines the missing
information from the information stored in the database (block
1415).
[0086] FIG. 15 illustrates an example MIMO communications device
1500, highlighting the architecture of MIMO communications device
1500. MIMO communications device 1500 includes a central processing
unit 1505 and an array of antennas 1510 coupled to central
processing unit 1505. Array of antennas 1510 may include any number
of antennas, but for large scale MIMO implementations, it is
expected that array of antennas 1510 includes on the order of
hundreds, thousands, tens of thousands, or more antennas. Central
processing unit 1505 may be a single processor or a multi-processor
system. Not shown in FIG. 15 are ancillary circuitry such as
memories, network interfaces, user interfaces, power supplies, and
so forth.
[0087] FIG. 16 illustrates an example MIMO communications system
1600. Communications system 1600 includes a MIMO communications
device 1605 with a central processing unit 1610 and an antenna
array 1615. Antennas of antenna array 1615 may be arranged in a
one-, two-, or three-dimensional array with regular or irregular
spacing between antennas. Communications system 1600 also includes
a positioning system 1620 that is configured to transmit orthogonal
reference signals to assist in determining position information of
antennas of antenna array 1615. Communications system 1600 also
includes a main transmission source 1625 communicating with MIMO
communications device 1605.
[0088] Communications system 1600 also includes a database 1630
configured to store information paths and sources, as well as PED
information. Database 1630 may be accessible by MIMO communications
device 1605. Communications system 1600 also includes an
association device 1635 configured to determine associations
between sources and paths. Association device 1635 may implement
techniques such as those described herein to associate sources and
paths. Although shown in FIG. 16 as a standalone device,
association device 1635 may be co-located with another entity in
communications system 1600. As an illustrative example, association
device 1635 may be co-located with database 1630, positioning
system 1620, a transmission point, a MIMO communications device,
and so on.
[0089] FIG. 17 illustrates a block diagram of an embodiment
processing system 1700 for performing methods described herein,
which may be installed in a host device. As shown, the processing
system 1700 includes a processor 1704, a memory 1706, and
interfaces 1710-1714, which may (or may not) be arranged as shown
in FIG. 17. The processor 1704 may be any component or collection
of components adapted to perform computations and/or other
processing related tasks, and the memory 1706 may be any component
or collection of components adapted to store programming and/or
instructions for execution by the processor 1904. In an embodiment,
the memory 1706 includes a non-transitory computer readable medium.
The interfaces 1710, 1712, 1714 may be any component or collection
of components that allow the processing system 1700 to communicate
with other devices/components and/or a user. For example, one or
more of the interfaces 1710, 1712, 1714 may be adapted to
communicate data, control, or management messages from the
processor 1704 to applications installed on the host device and/or
a remote device. As another example, one or more of the interfaces
1710, 1712, 1714 may be adapted to allow a user or user device
(e.g., personal computer (PC), etc.) to interact/communicate with
the processing system 1700. The processing system 1700 may include
additional components not depicted in FIG. 17, such as long term
storage (e.g., non-volatile memory, etc.).
[0090] In some embodiments, the processing system 1700 is included
in a network device that is accessing, or part otherwise of, a
telecommunications network. In one example, the processing system
1700 is in a network-side device in a wireless or wireline
telecommunications network, such as a base station, a relay
station, a scheduler, a controller, a gateway, a router, an
applications server, or any other device in the telecommunications
network. In other embodiments, the processing system 1700 is in a
user-side device accessing a wireless or wireline
telecommunications network, such as a mobile station, a user
equipment (UE), a personal computer (PC), a tablet, a wearable
communications device (e.g., a smartwatch, etc.), or any other
device adapted to access a telecommunications network.
[0091] In some embodiments, one or more of the interfaces 1710,
1712, 1714 connects the processing system 1700 to a transceiver
adapted to transmit and receive signaling over the
telecommunications network. FIG. 18 illustrates a block diagram of
a transceiver 1800 adapted to transmit and receive signaling over a
telecommunications network. The transceiver 1800 may be installed
in a host device. As shown, the transceiver 1800 comprises a
network-side interface 1802, a coupler 1804, a transmitter 1806, a
receiver 1808, a signal processor 1810, and a device-side interface
1812. The network-side interface 1802 may include any component or
collection of components adapted to transmit or receive signaling
over a wireless or wireline telecommunications network. The coupler
1804 may include any component or collection of components adapted
to facilitate bi-directional communication over the network-side
interface 1802. The transmitter 1806 may include any component or
collection of components (e.g., up-converter, power amplifier,
etc.) adapted to convert a baseband signal into a modulated carrier
signal suitable for transmission over the network-side interface
1802. The receiver 1808 may include any component or collection of
components (e.g., down-converter, low noise amplifier, etc.)
adapted to convert a carrier signal received over the network-side
interface 1802 into a baseband signal. The signal processor 1810
may include any component or collection of components adapted to
convert a baseband signal into a data signal suitable for
communication over the device-side interface(s) 1812, or
vice-versa. The device-side interface(s) 1812 may include any
component or collection of components adapted to communicate
data-signals between the signal processor 1810 and components
within the host device (e.g., the processing system 1700, local
area network (LAN) ports, etc.).
[0092] The transceiver 1800 may transmit and receive signaling over
any type of communications medium. In some embodiments, the
transceiver 1800 transmits and receives signaling over a wireless
medium. For example, the transceiver 1800 may be a wireless
transceiver adapted to communicate in accordance with a wireless
telecommunications protocol, such as a cellular protocol (e.g.,
long-term evolution (LTE), etc.), a wireless local area network
(WLAN) protocol (e.g., Wi-Fi, etc.), or any other type of wireless
protocol (e.g., Bluetooth, near field communication (NFC), etc.).
In such embodiments, the network-side interface 1802 comprises one
or more antenna/radiating elements. For example, the network-side
interface 1802 may include a single antenna, multiple separate
antennas, or a multi-antenna array configured for multi-layer
communication, e.g., single input multiple output (SIMO), multiple
input single output (MISO), multiple input multiple output (MIMO),
etc. In other embodiments, the transceiver 1800 transmits and
receives signaling over a wireline medium, e.g., twisted-pair
cable, coaxial cable, optical fiber, etc. Specific processing
systems and/or transceivers may utilize all of the components
shown, or only a subset of the components, and levels of
integration may vary from device to device.
[0093] Although the present disclosure and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the spirit and scope of the disclosure as defined by the
appended claims.
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