U.S. patent application number 14/413382 was filed with the patent office on 2016-09-22 for pilot time slot hopping.
The applicant listed for this patent is SONY CORPORATION. Invention is credited to Erik Bengtsson.
Application Number | 20160277167 14/413382 |
Document ID | / |
Family ID | 50685981 |
Filed Date | 2016-09-22 |
United States Patent
Application |
20160277167 |
Kind Code |
A1 |
Bengtsson; Erik |
September 22, 2016 |
PILOT TIME SLOT HOPPING
Abstract
Embodiments are directed to systems, methods and computer
program products for pilot time slot hopping to mitigate
interference-based pilot time slot contamination. Embodiments
include generating a multiple input multiple output (MIMO) system
message frame structure comprising a header comprising a plurality
of header time slots, an uplink (UL) time slot (optional), and a
downlink (DL) time slot. Generating includes determining, based on
a predetermined scheme, allocation of at least one of the plurality
of header time slots to at least one user device within a
predetermined area.
Inventors: |
Bengtsson; Erik; (Eslov,
SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SONY CORPORATION |
Tokyo |
|
JP |
|
|
Family ID: |
50685981 |
Appl. No.: |
14/413382 |
Filed: |
March 31, 2014 |
PCT Filed: |
March 31, 2014 |
PCT NO: |
PCT/IB2014/060314 |
371 Date: |
January 7, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 5/14 20130101; H04L
5/0051 20130101; H04B 7/0413 20130101; H04L 5/0082 20130101; H04L
5/0073 20130101; H04L 5/0092 20130101 |
International
Class: |
H04L 5/00 20060101
H04L005/00; H04L 5/14 20060101 H04L005/14; H04B 7/04 20060101
H04B007/04 |
Claims
1. A method for pilot time slot hopping, the method comprising:
generating, using a processing device, a multiple input multiple
output (MIMO) system message frame structure comprising a header
comprising a plurality of header time slots, and a downlink (DL)
time slot, wherein generating comprises: determining, based on a
predetermined scheme, allocation of at least one of the plurality
of header time slots to at least one user device within a
predetermined area.
2. The method of claim 1, wherein the header is a user device
training sequence header.
3. The method of claim 1, wherein the header time slots are pilot
time slots.
4. The method of claim 1, wherein one of a plurality of base
stations (BSs) and/or access points (APs) comprises the processing
device; and wherein each of the plurality of BSs and/or APs are
programmed for time synchronization of the frame structure such
that each BS and/or AP recognizes when in time the header occurs
during MIMO system message transmission.
5. The method of claim 1, wherein generating the MIMO system
message frame structure further comprises: determining
re-allocation, based on the predetermined scheme, periodically of
at least one of the plurality of header time slots to at least one
user device within the predetermined area.
6. The method of claim 5, wherein the re-allocation is determined
periodically at least every millisecond.
7. The method of claim 1, further comprising: determining, by the
processing device, that interference-based pilot time slot
contamination mitigation is needed; wherein generating the MIMO
system message frame structure including determining allocation of
the at least one of the plurality of header time slots to the at
least one user device is performed in response to the determination
that interference-based pilot time slot contamination mitigation is
needed.
8. The method of claim 7, further comprising: determining, by the
processing device, that interference-based pilot time slot
contamination mitigation is not needed; and based on the
determination that interference-based pilot time slot contamination
mitigation is not needed, maintaining present allocation of the at
least one of the plurality of header time slots to the at least one
user device.
9. The method of claim 1, further comprising: subsequent to
generating the MIMO system message frame structure including
determining allocation of the at least one of the plurality of
header time slots to the at least one user device, detecting, by
the processing device, that interference-based pilot time slot
contamination is occurring; and in response to detecting that
interference-based pilot time slot contamination is occurring,
determining re-allocation, based on the predetermined scheme, of at
least one of the plurality of header time slots to at least one
user device within the predetermined area in order to mitigate the
detected contamination.
10. The method of claim 1, wherein the plurality of header time
slots comprises a first plurality of header time slots and a second
plurality of header time slots; wherein the first plurality of
header time slots and the second plurality of header time slots are
different; and wherein determining allocation of at least one of
the plurality of header time slots to at least one user device
comprises determining allocation of the first plurality of header
time slots based on the predetermined scheme and without
determining allocation of the second plurality of header time slots
based on the predetermined scheme.
11. The method of claim 1, wherein generating the MIMO system
message frame structure further comprises: determining
re-allocation, based on a second predetermined scheme, of at least
one of the plurality of header time slots to at least one user
device within the predetermined area; and wherein: the second
predetermined scheme is the same as the scheme; wherein the second
scheme is initiated at a second start time different from a start
time of the scheme; or wherein the second scheme and the scheme
both utilize the same pseudo-random pattern function but the second
scheme utilizes at least one different seed than the scheme; or the
second predetermined scheme is different than the scheme.
12. The method of claim 1, wherein allocation is based on one of a
plurality of predetermined schemes; wherein generating the MIMO
system message frame structure further comprises: dynamically
selecting, in order to avoid allocation of the same header time
slots to multiple user devices, a different predetermined scheme
for each re-allocation of header time slots; and determining
re-allocation periodically and/or as needed to avoid contamination,
based on the dynamically selected predetermined scheme, of at least
one of the plurality of header time slots to at least one user
device within the predetermined area.
13. An apparatus for pilot time slot hopping, the apparatus
comprising: a memory; a processor; and a module stored in the
memory, executable by the processor, and configured to: generate a
multiple input multiple output (MIMO) system message frame
structure comprising a header comprising a plurality of header time
slots, and a downlink (DL) time slot, wherein generating comprises:
determining, based on a predetermined scheme, allocation of at
least one of the plurality of header time slots to at least one
user device within a predetermined area.
14. The apparatus of claim 13, wherein the apparatus is one of a
plurality of base stations (BSs) and/or access points (APs); and
wherein each of the plurality of BSs and/or APs are programmed for
time synchronization of the frame structure such that each BS
and/or AP recognizes when in time the header occurs during MIMO
system message transmission.
15. The apparatus of claim 13, wherein generating the MIMO system
message frame structure further comprises: determining
re-allocation, based on the predetermined scheme, periodically of
at least one of the plurality of header time slots to at least one
user device within the predetermined area.
16. The apparatus of claim 13, wherein the module is further
configured to: determine that interference-based pilot time slot
contamination mitigation is needed; wherein generating the MIMO
system message frame structure including determining allocation of
the at least one of the plurality of header time slots to the at
least one user device is performed in response to the determination
that interference-based pilot time slot contamination mitigation is
needed.
17. The apparatus of claim 13, wherein the module is further
configured to: subsequent to generating the MIMO system message
frame structure including determining allocation of the at least
one of the plurality of header time slots to the at least one user
device, detect that interference-based pilot time slot
contamination is occurring; and in response to detecting that
interference-based pilot time slot contamination is occurring,
determining re-allocation, based on the predetermined scheme, of at
least one of the plurality of header time slots to at least one
user device within the predetermined area in order to mitigate the
detected contamination.
18. The apparatus of claim 13, wherein the plurality of header time
slots comprises a first plurality of header time slots and a second
plurality of header time slots; wherein the first plurality of
header time slots and the second plurality of header time slots are
different; and wherein determining allocation of at least one of
the plurality of header time slots to at least one user device
comprises determining allocation of the first plurality of header
time slots based on the predetermined scheme and without
determining allocation of the second plurality of header time slots
based on the predetermined scheme.
19. The apparatus of claim 13, wherein generating the MIMO system
message frame structure further comprises: determining
re-allocation, based on a second predetermined scheme, of at least
one of the plurality of header time slots to at least one user
device within the predetermined area; and wherein the second
predetermined scheme is different than the scheme.
20. A computer program product for pilot time slot hopping, the
computer program product comprising: a non-transitory
computer-readable medium comprising a set of codes for causing a
computer to: generate a multiple input multiple output (MIMO)
system message frame structure comprising a header comprising a
plurality of header time slots, and a downlink (DL) time slot,
wherein generating comprises: determining, based on a predetermined
scheme, allocation of at least one of the plurality of header time
slots to at least one user device within a predetermined area.
Description
BACKGROUND ART
[0001] The Third Generation Partnership Project (3GPP) radio access
network (RAN) collaboration has addressed massive MIMO systems, and
the proposed frame structure is a time division duplex (TDD) with a
"header" time slot for user equipment (UE) or user device pilot or
training sequence transmission, an uplink (UL) timeslot (optional)
and a downlink (DL) timeslot.
SUMMARY
[0002] Embodiments of the invention are directed to systems,
methods and computer program products for pilot time slot hopping
to mitigate interference-based pilot time slot contamination. The
method includes generating, using a processing device, a multiple
input multiple output (MIMO) system message frame structure
comprising a header comprising a plurality of header time slots, an
uplink (UL) time slot (optional), and a downlink (DL) time slot,
where generating comprises determining, based on a predetermined
scheme, allocation of at least one of the plurality of header time
slots to at least one user device within a predetermined area.
[0003] In some embodiments, the header is a user device training
sequence header. In some embodiments, the header time slots are
pilot time slots.
[0004] In some embodiments, one of a plurality of base stations
(BSs) and/or access points (APs) comprises the processing device;
and each of the plurality of BSs and/or APs are programmed for time
synchronization of the frame structure such that each BS and/or AP
recognizes when in time the header occurs during MIMO system
message transmission.
[0005] In some embodiments, generating the MIMO system message
frame structure further comprises determining re-allocation, based
on the predetermined scheme, periodically of at least one of the
plurality of header time slots to at least one user device within
the predetermined area. In some such embodiments, the re-allocation
is determined periodically at least every millisecond.
[0006] In some embodiments, the method also includes determining,
by the processing device, that interference-based pilot time slot
contamination mitigation is needed; and where generating the MIMO
system message frame structure including determining allocation of
the at least one of the plurality of header time slots to the at
least one user device is performed in response to the determination
that interference-based pilot time slot contamination mitigation is
needed. In some such embodiments, the method also includes
determining, by the processing device, that interference-based
pilot time slot contamination mitigation is not needed; and based
on the determination that interference-based pilot time slot
contamination mitigation is not needed, maintaining present
allocation of the at least one of the plurality of header time
slots to the at least one user device.
[0007] In some embodiments, the method also includes, subsequent to
generating the MIMO system message frame structure including
determining allocation of the at least one of the plurality of
header time slots to the at least one user device, detecting, by
the processing device, that interference-based pilot time slot
contamination is occurring; and, in response to detecting that
interference-based pilot time slot contamination is occurring,
determining re-allocation, based on the predetermined scheme, of at
least one of the plurality of header time slots to at least one
user device within the predetermined area in order to mitigate the
detected contamination.
[0008] In some embodiments, the plurality of header time slots
comprises a first plurality of header time slots and a second
plurality of header time slots; the first plurality of header time
slots and the second plurality of header time slots are different;
and determining allocation of at least one of the plurality of
header time slots to at least one user device comprises determining
allocation of the first plurality of header time slots based on the
predetermined scheme and without determining allocation of the
second plurality of header time slots based on the predetermined
scheme.
[0009] In some embodiments, generating the MIMO system message
frame structure further comprises determining re-allocation, based
on a second predetermined scheme, of at least one of the plurality
of header time slots to at least one user device within the
predetermined area; and wherein (1) the second predetermined scheme
is the same as the scheme, where the second scheme is initiated at
a second start time different from a start time of the scheme; or
where the second scheme and the scheme both utilize the same
pseudo-random pattern function but the second scheme utilizes at
least one different seed than the scheme; or (2) the second
predetermined scheme is different than the scheme.
[0010] In some embodiments, allocation is based on one of a
plurality of predetermined schemes; generating the MIMO system
message frame structure further comprises dynamically selecting, in
order to avoid allocation of the same header time slots to multiple
user devices, a different predetermined scheme for each
re-allocation of header time slots; determining re-allocation
periodically and/or as needed to avoid contamination, based on the
dynamically selected predetermined scheme, of at least one of the
plurality of header time slots to at least one user device within
the predetermined area.
[0011] According to embodiments of the invention, an apparatus for
pilot time slot hopping to mitigate interference-based pilot time
slot contamination includes a memory; a processor; and a module
stored in the memory, executable by the processor, and configured
to generate a multiple input multiple output (MIMO) system message
frame structure comprising a header comprising a plurality of
header time slots, an uplink (UL) time slot (optional), and a
downlink (DL) time slot, where generating comprises determining,
based on a predetermined scheme, allocation of at least one of the
plurality of header time slots to at least one user device within a
predetermined area.
[0012] In some embodiments, the apparatus is one of a plurality of
base stations (BSs) and/or access points (APs); and each of the
plurality of BSs and/or APs are programmed for time synchronization
of the frame structure such that each BS and/or AP recognizes when
in time the header occurs during MIMO system message
transmission.
[0013] In some embodiments, generating the MIMO system message
frame structure further comprises determining re-allocation, based
on the predetermined scheme, periodically of at least one of the
plurality of header time slots to at least one user device within
the predetermined area.
[0014] In some embodiments, the module is further configured to
determine that interference-based pilot time slot contamination
mitigation is needed; and where generating the MIMO system message
frame structure including determining allocation of the at least
one of the plurality of header time slots to the at least one user
device is performed in response to the determination that
interference-based pilot time slot contamination mitigation is
needed.
[0015] In some embodiments, the module is further configured to,
subsequent to generating the MIMO system message frame structure
including determining allocation of the at least one of the
plurality of header time slots to the at least one user device,
detect that interference-based pilot time slot contamination is
occurring; in response to detecting that interference-based pilot
time slot contamination is occurring, determining re-allocation,
based on the predetermined scheme, of at least one of the plurality
of header time slots to at least one user device within the
predetermined area in order to mitigate the detected
contamination.
[0016] In some embodiments, the plurality of header time slots
comprises a first plurality of header time slots and a second
plurality of header time slots; the first plurality of header time
slots and the second plurality of header time slots are different;
and determining allocation of at least one of the plurality of
header time slots to at least one user device comprises determining
allocation of the first plurality of header time slots based on the
predetermined scheme and without determining allocation of the
second plurality of header time slots based on the predetermined
scheme.
[0017] In some embodiments, generating the MIMO system message
frame structure further comprises determining re-allocation, based
on a second predetermined scheme, of at least one of the plurality
of header time slots to at least one user device within the
predetermined area; and the second predetermined scheme is
different than the scheme.
[0018] According to embodiments of the invention, a computer
program product for pilot time slot hopping to mitigate
interference-based pilot time slot contamination includes a
non-transitory computer-readable medium comprising a set of codes
for causing a computer to generate a multiple input multiple output
(MIMO) system message frame structure comprising a header
comprising a plurality of header time slots, an uplink (UL) time
slot (optional), and a downlink (DL) time slot, where generating
includes determining, based on a predetermined scheme, allocation
of at least one of the plurality of header time slots to at least
one user device within a predetermined area.
BRIEF DESCRIPTION OF DRAWINGS
[0019] Having thus described embodiments of the invention in
general terms, reference will now be made to the accompanying
drawings, where:
[0020] FIG. 1 illustrates two UEs that are allocated difference
pilot time slots based on predetermined schemes according to
embodiments of the invention;
[0021] FIG. 2 illustrates an environment wherein user equipment
devices and network systems operate according to embodiments of the
invention;
[0022] FIG. 3 illustrates a flowchart of a method 300 for pilot
time slot hopping to mitigate interference-based pilot time slot
contamination according to embodiments of the invention;
[0023] FIG. 4 illustrates a flowchart of another method 400 for
pilot time slot hopping to mitigate interference-based pilot time
slot contamination according to embodiments of the invention;
and
[0024] FIG. 5 illustrates a flowchart of another method 500 for
pilot time slot hopping to mitigate interference-based pilot time
slot contamination according to embodiments of the invention.
DESCRIPTION OF EMBODIMENTS
[0025] Embodiments of the present invention now may be described
more fully hereinafter with reference to the accompanying drawings,
in which some, but not all, embodiments of the invention are shown.
Indeed, the invention may be embodied in many different forms and
should not be construed as limited to the embodiments set forth
herein; rather, these embodiments are provided so that this
disclosure may satisfy applicable legal requirements. Like numbers
refer to like elements throughout.
[0026] As mentioned above, in massive MIMO systems, the proposed
frame structure is TDD with a "header", UL and DL. For efficient
network transmission, the header or pilot time slots for multiple
UEs should be orthogonal (non-overlapping). This may be difficult
because the pilot time slot space or time allocation is limited.
One option is to achieve orthogonality by assigning a time slot
within the header for each unique UE in a particular area, such as
a cell. However, the limited number of time slots, particularly in
densely populated cells, may require that time slots are reused for
multiple UEs. Further, in some unlicensed bands, reuse of time
slots may be required. Thus, when two or more UEs accidentally or
inadvertently use the same header time slot, interference will
occur, such as channel state information (CSI) interference and
inaccuracies.
[0027] Accordingly, embodiments of the invention are directed to
systems, methods and computer program products for pilot time slot
hopping to mitigate interference-based pilot time slot
contamination. Embodiments include generating a multiple input
multiple output (MIMO) system message frame structure comprising a
header comprising a plurality of header time slots, an uplink (UL)
time slot (optional), and a downlink (DL) time slot. Generating
includes determining, based on a predetermined scheme, allocation
of at least one of the plurality of header time slots to at least
one user device within a predetermined area. The scheme may be or
include a pseudo-random scheme, a cyclic scheme, a non-random
scheme, an orthogonal scheme and/or the like.
[0028] Referring now to FIG. 1, diagram illustrates a MIMO system
message frame structure where UE1 and UE2 have been allocated
different time slots within the header for each training sequence
according to embodiments of the invention. As shown, for each
training sequence, the time slots allocated to UE1 and UE2 do not
overlap and therefore, orthogonality is achieved.
[0029] Referring now to FIG. 2, a network environment 200 is
illustrated in accordance with one embodiment of the present
invention. As illustrated in FIG. 2, the network system 208 is
operatively coupled, via a network 201 to the user equipment 204
and/or 206. In this configuration, the network system 208 may send
information to and receive information from the user equipment
devices 204 and/or 206. FIG. 2 illustrates only one example of an
embodiment of a network environment 200, and it will be appreciated
that in other embodiments one or more of the systems, devices, or
servers may be combined into a single system, device, or server, or
be made up of multiple systems, devices, or servers.
[0030] The network 201 may be a global area network (GAN), such as
the Internet, a wide area network (WAN), a local area network
(LAN), a telecommunication network or any other type of network or
combination of networks. The network 201 may provide for wireline,
wireless, or a combination wireline and wireless communication
between devices on the network 201. In some embodiments, the users
202 and 205 are individuals who maintain cellular products with one
or more providers.
[0031] As illustrated in FIG. 2, the network system 208 generally
comprises a communication device 246, a processing device 248, and
a memory device 250. As used herein, the term "processing device"
generally includes circuitry used for implementing the
communication and/or logic functions of the particular system. For
example, a processing device may include a digital signal processor
device, a microprocessor device, and various analog-to-digital
converters, digital-to-analog converters, and other support
circuits and/or combinations of the foregoing. Control and signal
processing functions of the system are allocated between these
processing devices according to their respective capabilities. The
processing device may include functionality to operate one or more
software programs based on computer-readable instructions thereof,
which may be stored in a memory device.
[0032] The processing device 248 is operatively coupled to the
communication device 246 and the memory device 250. The processing
device 248 uses the communication device 246 to communicate with
the network 201 and other devices on the network 201. As such, the
communication device 246 generally comprises a modem, server, or
other device for communicating with other devices on the network
201.
[0033] As further illustrated in FIG. 2, the network system 208
comprises computer-readable instructions 254 stored in the memory
device 250, which in one embodiment includes the computer-readable
instructions 254 of an application 258 including instructions for
performing one or more processes and/or method steps discussed
herein and/or one or more processes and/or method steps not
discussed herein. In some embodiments, the memory device 250
includes data storage 252 for storing data related to and/or used
by the application 258.
[0034] As illustrated in FIG. 2, the user equipment 206 (or user
device) generally comprises a communication device 236, a
processing device 238, and a memory device 240. The processing
device 238 is operatively coupled to the communication device 236
and the memory device 240. In some embodiments, the processing
device 238 may send or receive data from the user equipment 204,
and/or the network system 208 via the communication device 236 over
a network 201. As such, the communication device 236 generally
comprises a modem, server, or other device for communicating with
other devices on the network 201.
[0035] As further illustrated in FIG. 2, the user equipment 206
comprises computer-readable instructions 242 stored in the memory
device 240, which in one embodiment includes the computer-readable
instructions 242 of an application 244 including instructions for
performing one or more processes and/or method steps discussed
herein and/or one or more processes and/or method steps not
discussed herein.
[0036] It is understood that the servers, systems, and devices
described herein illustrate one embodiment of the invention. It is
further understood that one or more of the servers, systems, and
devices can be combined in other embodiments and still function in
the same or similar way as the embodiments described herein.
[0037] Referring now to FIG. 3, a flowchart illustrates a method
300 for pilot time slot hopping to mitigate interference-based
pilot time slot contamination according to embodiments of the
invention. The first step of method 300, as represented by block
310, is generating, using a processing device (such as a processing
device of a base station or access point), a multiple input
multiple output (MIMO) system message frame structure. The frame
structure includes a header comprising a plurality of header time
slots, an uplink (UL) time slot, and a downlink (DL) time slot. In
some embodiments, the frame structure only includes pilot and DL
time slots and does not include UL time slots. Accordingly, such
frames include no payload and may be utilized for UEs in idle
mode.
[0038] Generating the message frame structure, as represented by
block 320, includes determining, based on a predetermined scheme,
allocation of at least one of the plurality of header time slots to
at least one user device within a predetermined area. The scheme
may be pseudo-random, cyclical, non-random, orthogonal and/or the
like. In some cases, the header is a UE training sequence header
and it may be called a pilot time slot.
[0039] Various embodiments discussed herein assume that all base
stations (BSs) and/or access points (APs) are synchronized such
that they know when the header, UL and DL slots occur. In one
example, each of the plurality of BSs and/or APs are preprogrammed
for time synchronization of the frame structure such that each BS
and/or AP recognizes when in time the header occurs during MIMO
system message transmission. In other embodiments, the BS/APs are
contemporaneously programmed based on a feature, method, algorithm,
process, application or the like.
[0040] In various embodiments, the BS/AP allocates the pattern, but
in other embodiments, each UE selects a pattern and a UE-ID is
included in the pilot time slot. Orthogonal hopping patterns might
be generated in different ways. For example, in some cases
different random patterns are selected as discussed above. However,
in other cases, the same pattern may be used with each UE selecting
or being allocated (by a BS/AP) different start points or the same
"random pattern function" but with different seeds.
[0041] In some embodiments, the method 300 includes periodically
determining re-allocation, based on the predetermined scheme, of at
least one of the plurality of header time slots to at least one
user device within the predetermined area, as represented by block
330. In some such embodiments, re-allocation may be periodically
determined at least every millisecond.
[0042] Referring now to FIG. 4, a method 400 includes some steps
that may be included with the steps discussed with reference to
method 300 of FIG. 3 according to embodiments of the invention.
First, as represented by block 410, the system determines whether
interference-based pilot time slot contamination mitigation is
needed. This may be done by detecting whether contamination or
interference of transmission is occurring on the network. The
system may determine contamination is occurring in a variety of
ways. For example, pilot contamination will cause increased BER
(bit error state), SNR (signal to noise and interferer ratio)
degradation or contamination may possibly be detected in the
footprint. Applying time slot hopping might mitigate such
contamination by itself or may require additional methods for
effective contamination mitigation. Accordingly, other tools may be
used in conjunction with the time hopping methods disclosure herein
to improve communication. Such other methods that might be used in
conjunction include frequency band re-selection, synchronization to
neighbor cells, applying additional multiple access (MA) method(s)
and/or applying spreading (coding), and/or changing modulation
scheme(s) for higher robustness. In some cases, synchronization
might be required in order for hopping to assist in mitigation of
contamination, therefore requiring pairing with another method in
some cases. For example, if a UE or BS/AP detects high BER and
attempts to change the pilot time slot (based on a standard time
slot allocation) without improving the high BER, time slot hopping
can be activated and average BER may thereby improve.
[0043] If mitigation is needed, as represented by block 420,
generating the MIMO system message frame structure includes
determining allocation of the at least one of the plurality of
header time slots to the at least one UE. In other words,
allocation of the header time slots to the UEs may be performed in
response to a determination that contamination mitigation is
needed.
[0044] If it is determined that mitigation is not needed, as
represented by block 430, the method includes maintaining present
allocation of the header time slots to the UEs. In other words, the
system may maintain the current time slot allocation in response to
determining that no contamination mitigation is necessary. The
system may determine that contamination is not occurring (or is not
likely to occur) by measuring metrics described above such as the
BER. If one or more of such metrics are better, time slot hopping
may be deactivated. In some cases, one or more of the metrics are
continually (or periodically) monitored when/while time slot
hopping is deactivated, and if it is determined that one or more of
the metrics is not meeting desired thresholds or standards, then
time hopping may then be reactivated. For example, the system may
detect that there is high BER on only some frames when a collision
occurs. In such a cases, the system may deactivate time slot
hopping and finding/allocating an open or "free" time slot may
prove more economical and/or efficient.
[0045] In some embodiments, the method includes detecting that
interference-based pilot time slot contamination is occurring after
generating the MIMO system message frame structure (see step 310.
Then, in response to detecting that contamination is occurring with
the originally allocated time slots, the method then determines
re-allocation. The re-allocation may be based on the same
predetermined scheme that was used in the original allocation.
[0046] In some embodiments, allocation based on predetermined (or
dynamically selected) schemes is only applied to one or more
sub-sets of the entire set of pilot time slots. In other words, the
plurality of header time slots may be broken into a first plurality
of header time slots and a second plurality of header time slots,
where the first plurality of header time slots and the second
plurality of header time slots are different. In these embodiments,
the allocation of one of the sub-sets of time slots may be
determined based on the predetermined (or dynamically selected)
scheme and allocation of the other sub-set(s) may be based on some
other scheme, such as a simple assignment of time slots to UEs.
[0047] In some embodiments, the system uses different patterns or
schemes dynamically selected in order to avoid using the same
schemes. Then, as represented by block 520, the system may
determine re-allocation based on a second predetermined scheme that
is different than the originally used scheme.
[0048] Referring now to FIG. 5, a method 500 includes steps that
may be included with the steps discussed with reference to method
300 of FIG. 3. In some cases, allocation is based on one of a
plurality of predetermined schemes. Generating the message frame
structure may include dynamically selecting, in order to avoid
allocation of the same header time slots to multiple user devices,
a different predetermined scheme for each re-allocation of header
time slots, as represented by block 510. Then, the system
determines re-allocation periodically and/or as needed to avoid
contamination, based on the dynamically selected predetermined
scheme, as represented by block 520.
[0049] When there are many UEs connected to a single BS or AP
within a single cell, various embodiments of the invention enable
orthogonal allocation of pilot time slots using pilot time slot
hopping methods discussed herein. Thus, a possible contamination
from a neighboring cell may have the same system impact but will
not harm only a single UE's transmissions. Further, introduction of
time slot hopping has little or no throughput cost.
[0050] Although many embodiments of the present invention have just
been described above, the present invention may be embodied in many
different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are
provided so that this disclosure will satisfy applicable legal
requirements. Also, it will be understood that, where possible, any
of the advantages, features, functions, devices, and/or operational
aspects of any of the embodiments of the present invention
described and/or contemplated herein may be included in any of the
other embodiments of the present invention described and/or
contemplated herein, and/or vice versa. In addition, where
possible, any terms expressed in the singular form herein are meant
to also include the plural form and/or vice versa, unless
explicitly stated otherwise. As used herein, "at least one" shall
mean "one or more" and these phrases are intended to be
interchangeable. Accordingly, the terms "a" and/or "an" shall mean
"at least one" or "one or more," even though the phrase "one or
more" or "at least one" is also used herein. Like numbers refer to
like elements throughout.
[0051] As will be appreciated by one of ordinary skill in the art
in view of this disclosure, the present invention may include
and/or be embodied as an apparatus (including, for example, a
system, machine, device, computer program product, and/or the
like), as a method (including, for example, a business method,
computer-implemented process, and/or the like), or as any
combination of the foregoing. Accordingly, embodiments of the
present invention may take the form of an entirely business method
embodiment, an entirely software embodiment (including firmware,
resident software, micro-code, stored procedures in a database,
etc.), an entirely hardware embodiment, or an embodiment combining
business method, software, and hardware aspects that may generally
be referred to herein as a "system." Furthermore, embodiments of
the present invention may take the form of a computer program
product that includes a computer-readable storage medium having one
or more computer-executable program code portions stored therein.
As used herein, a processor, which may include one or more
processors, may be "configured to" perform a certain function in a
variety of ways, including, for example, by having one or more
general-purpose circuits perform the function by executing one or
more computer-executable program code portions embodied in a
computer-readable medium, and/or by having one or more
application-specific circuits perform the function.
[0052] It will be understood that any suitable computer-readable
medium may be utilized. The computer-readable medium may include,
but is not limited to, a non-transitory computer-readable medium,
such as a tangible electronic, magnetic, optical, electromagnetic,
infrared, and/or semiconductor system, device, and/or other
apparatus. For example, in some embodiments, the non-transitory
computer-readable medium includes a tangible medium such as a
portable computer diskette, a hard disk, a random access memory
(RAM), a read-only memory (ROM), an erasable programmable read-only
memory (EPROM or Flash memory), a compact disc read-only memory
(CD-ROM), and/or some other tangible optical and/or magnetic
storage device. In other embodiments of the present invention,
however, the computer-readable medium may be transitory, such as,
for example, a propagation signal including computer-executable
program code portions embodied therein.
[0053] One or more computer-executable program code portions for
carrying out operations of the present invention may include
object-oriented, scripted, and/or unscripted programming languages,
such as, for example, Java, Perl, Smalltalk, C++, SAS, SQL, Python,
Objective C, JavaScript, and/or the like. In some embodiments, the
one or more computer-executable program code portions for carrying
out operations of embodiments of the present invention are written
in conventional procedural programming languages, such as the "C"
programming languages and/or similar programming languages. The
computer program code may alternatively or additionally be written
in one or more multi-paradigm programming languages, such as, for
example, F#.
[0054] Some embodiments of the present invention are described
herein with reference to flowchart illustrations and/or block
diagrams of apparatus and/or methods. It will be understood that
each block included in the flowchart illustrations and/or block
diagrams, and/or combinations of blocks included in the flowchart
illustrations and/or block diagrams, may be implemented by one or
more computer-executable program code portions. These one or more
computer-executable program code portions may be provided to a
processor of a general purpose computer, special purpose computer,
and/or some other programmable data processing apparatus in order
to produce a particular machine, such that the one or more
computer-executable program code portions, which execute via the
processor of the computer and/or other programmable data processing
apparatus, create mechanisms for implementing the steps and/or
functions represented by the flowchart(s) and/or block diagram
block(s).
[0055] The one or more computer-executable program code portions
may be stored in a transitory and/or non-transitory
computer-readable medium (e.g., a memory, etc.) that can direct,
instruct, and/or cause a computer and/or other programmable data
processing apparatus to function in a particular manner, such that
the computer-executable program code portions stored in the
computer-readable medium produce an article of manufacture
including instruction mechanisms which implement the steps and/or
functions specified in the flowchart(s) and/or block diagram
block(s).
[0056] The one or more computer-executable program code portions
may also be loaded onto a computer and/or other programmable data
processing apparatus to cause a series of operational steps to be
performed on the computer and/or other programmable apparatus. In
some embodiments, this produces a computer-implemented process such
that the one or more computer-executable program code portions
which execute on the computer and/or other programmable apparatus
provide operational steps to implement the steps specified in the
flowchart(s) and/or the functions specified in the block diagram
block(s). Alternatively, computer-implemented steps may be combined
with, and/or replaced with, operator- and/or human-implemented
steps in order to carry out an embodiment of the present
invention.
[0057] While certain exemplary embodiments have been described and
shown in the accompanying drawings, it is to be understood that
such embodiments are merely illustrative of and not restrictive on
the broad invention, and that this invention not be limited to the
specific constructions and arrangements shown and described, since
various other changes, combinations, omissions, modifications and
substitutions, in addition to those set forth in the above
paragraphs, are possible. Those skilled in the art will appreciate
that various adaptations, modifications, and combinations of the
just described embodiments can be configured without departing from
the scope and spirit of the invention. Therefore, it is to be
understood that, within the scope of the appended claims, the
invention may be practiced other than as specifically described
herein.
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