U.S. patent application number 17/365493 was filed with the patent office on 2021-10-21 for base station, user equipment and methods therein for control timing configuration assignment in a multiple cell communications network.
The applicant listed for this patent is Telefonaktiebolaget LM Ericsson (publ). Invention is credited to Robert Baldemair, Jung-Fu Cheng, Mattias Frenne, Dirk Gerstenberger, Daniel Larsson.
Application Number | 20210328753 17/365493 |
Document ID | / |
Family ID | 1000005695517 |
Filed Date | 2021-10-21 |
United States Patent
Application |
20210328753 |
Kind Code |
A1 |
Cheng; Jung-Fu ; et
al. |
October 21, 2021 |
Base Station, User Equipment and Methods Therein for Control Timing
Configuration Assignment in a Multiple Cell Communications
Network
Abstract
Example embodiments presented herein are directed towards a base
station and method therein, for configuring control timing to and
from a user equipment in a multiple component cell communications
network. Example embodiments presented herein are also directed
towards a user equipment and method therein, for configuration of
control timing for a user equipment in a multiple component cell
communications network.
Inventors: |
Cheng; Jung-Fu; (Fremont,
CA) ; Baldemair; Robert; (Solna, SE) ; Frenne;
Mattias; (Uppsala, SE) ; Gerstenberger; Dirk;
(Stockholm, SE) ; Larsson; Daniel; (Lund,
SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Telefonaktiebolaget LM Ericsson (publ) |
Stockholm |
|
SE |
|
|
Family ID: |
1000005695517 |
Appl. No.: |
17/365493 |
Filed: |
July 1, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15073315 |
Mar 17, 2016 |
11070346 |
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17365493 |
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13510201 |
May 16, 2012 |
9295055 |
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PCT/SE2012/050093 |
Jan 31, 2012 |
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15073315 |
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61524859 |
Aug 18, 2011 |
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61522698 |
Aug 12, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 76/27 20180201;
H04J 11/00 20130101; H04L 5/1469 20130101; H04W 72/0413 20130101;
H04L 5/16 20130101; H04W 72/042 20130101; H04W 88/02 20130101; H04W
72/0446 20130101; H04L 5/0053 20130101; H04L 1/1861 20130101; H04L
5/0055 20130101; H04L 5/14 20130101; H04L 1/1812 20130101; H04W
88/08 20130101; H04L 5/001 20130101 |
International
Class: |
H04L 5/14 20060101
H04L005/14; H04L 1/18 20060101 H04L001/18; H04W 72/04 20060101
H04W072/04; H04L 5/00 20060101 H04L005/00; H04L 5/16 20060101
H04L005/16; H04W 76/27 20060101 H04W076/27; H04J 11/00 20060101
H04J011/00 |
Claims
1. A method, in a base station, for determining at least one
control timing configuration number, the at least one control
timing configuration number indicating a subframe timing setting
for configuring control timing to and/or from a user equipment in a
multiple cell communications network, the method comprising:
determining the at least one control timing configuration number
for a plurality of aggregated cells associated with the user
equipment, each aggregated cell being associated with one of a
plurality of uplink-downlink configuration numbers, wherein at
least two uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal, and wherein each of the at least
one control timing configuration number is one of the plurality of
uplink-downlink configuration numbers; and assigning the at least
one timing configuration number to the user equipment.
2. The method of claim 1, wherein each of the uplink-downlink
configuration numbers defines a particular correlation of one or
more timing offsets with one or more subframes, the timing offsets
for transmission timing associated with a cell, and uplink-downlink
configuration numbers that are not equal define different
correlations.
3. The method of claim 1, wherein the determining the at least one
control timing configuration number comprises determining the at
least one control timing configuration number at the base station
based on rules for controlling Hybrid-Automatic Repeat Request
(HARQ) control timing among aggregated cells.
4. The method of claim 1, wherein the at least one control timing
configuration number is equal to one of the uplink-downlink
configuration numbers of the plurality of aggregated cells.
5. The method of claim 1, wherein the at least one control timing
configuration number is not equal to any of the uplink-downlink
configuration numbers of the plurality of aggregated cells.
6. The method of claim 1, wherein the determining comprises
determining the at least one control timing configuration number
such that control data is transmitted, to and from the user
equipment and the network, in a non-conflicting manner.
7. The method of claim 1, wherein the determining comprises
determining the at least one control timing configuration number
based on the uplink-downlink configuration numbers of the plurality
of aggregated cells.
8. The method of claim 7, wherein the determining further comprises
determining the at least one control timing configuration number
based on a subframe timing compatibility ordering.
9. The method of claim 8, wherein the determining further comprises
arranging the subframe timing compatibility ordering such that
uplink-downlink configurations on a higher level of the ordering
comprise uplink subframes that are a superset of all uplink
subframes from uplink-downlink configurations on a lower level of
the ordering.
10. The method of claim 8, wherein the determining further
comprises arranging the subframe timing compatibility ordering such
that uplink-downlink configurations on a lower level of the
ordering comprise downlink subframes that are a superset of all
downlink subframes from uplink-downlink configurations on a higher
level of the ordering.
11. The method of claim 1, wherein the assigning comprises
communicating the at least one control timing configuration number
to the user equipment via radio resource control (RRC)
signaling.
12. The method of claim 1, wherein the assigning comprises
assigning, in response to the presence of conflicting subframes, a
forward-subframe downlink scheduling timing with respect to a
physical downlink control channel (PDCCH).
13. The method of claim 1, wherein the assigning comprises
assigning, in response to the presence of conflicting subframes, a
cross component carrier forward-subframe downlink scheduling timing
with respect to a physical downlink control channel (PDCCH).
14. A base station for determining at least one control timing
configuration number, the at least one control timing configuration
number indicating a subframe timing setting for configuring control
timing to and/or from a user equipment in a multiple cell
communications network, the base station comprising a processor and
a memory, the memory containing instructions executable by the
processor whereby the base station is configured to: determine the
at least one control timing configuration number for a plurality of
aggregated cells associated with the user equipment, each
aggregated cell being associated with one of a plurality of
uplink-downlink configuration numbers, and wherein at least two
uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal, and wherein each of the at least
one control timing configuration number is one of the plurality of
uplink-downlink configuration numbers; and assign the at least one
control timing configuration number to the user equipment.
15. The base station of claim 14, wherein the base station is
configured to determine the at least one control timing
configuration number based on rules for controlling
Hybrid-Automatic Repeat Request (HARQ) control timing among
aggregated cells.
16. The base station of claim 14, wherein each of the
uplink-downlink configuration numbers defines a particular
correlation of one or more timing offsets with one or more
subframes, the timing offsets for transmission timing associated
with a cell, and uplink-downlink configuration numbers that are not
equal define different correlations.
17. The base station of claim 14, wherein the at least one control
timing configuration number is equal to one of the uplink-downlink
configuration numbers of the plurality of aggregated cells.
18. The base station of claim 14, wherein the at least one control
timing configuration number is not equal to any of the
uplink-downlink configuration numbers of the plurality of
aggregated cells.
19. The base station of claim 14, wherein the memory contains
instructions executable by the processor whereby the device is
configured to determine the at least one control timing
configuration number such that control data is transmitted, to and
from the user equipment and the network, in a non-conflicting
manner.
20. The base station of claim 14, wherein the memory contains
instructions executable by the processor whereby the device is
configured to determine the at least one control timing
configuration number based on the uplink-downlink configuration
numbers of the plurality of aggregated cells.
21. The base station of claim 20, wherein the memory contains
instructions executable by the processor whereby the device is
configured to determine the at least one control timing
configuration number further based on a subframe timing
compatibility ordering.
22. The base station of claim 21, wherein the subframe timing
compatibility ordering is arranged such that uplink-downlink
configurations on a higher level of the ordering comprise uplink
subframes that are a superset of all uplink subframes from
uplink-downlink configurations on a lower level of the
ordering.
23. The base station of claim 21, wherein the subframe timing
compatibility ordering is arranged such that uplink-downlink
configurations on a lower level of the ordering comprise downlink
subframes that are a superset of all downlink subframes from
uplink-downlink configurations on a higher level of the
ordering.
24. The base station of claim 14, wherein the memory contains
instructions executable by the processor whereby the device is
configured to communicate to the user equipment the at least one
control timing configuration number via radio resource control
(RRC) signaling.
25. The base station of claim 14, wherein the memory contains
instructions executable by the processor whereby the device is
configured to assign, in response to the presence of conflicting
subframes, a forward-subframe downlink scheduling timing with
respect to a physical downlink control channel (PDCCH).
26. The base station of claim 14, wherein the memory contains
instructions executable by the processor whereby the device is
configured to assign, in response to the presence of conflicting
subframes, a cross component carrier forward-subframe downlink
scheduling timing with respect to a physical downlink control
channel (PDCCH).
27. A non-transitory computer readable medium comprising a control
program stored thereon that, when executed by processing circuitry
of a base station in a communication network, causes the base
station to: determine at least one control timing configuration
number for a plurality of aggregated cells associated with a user
equipment, each aggregated cell being associated with one of a
plurality of uplink-downlink configuration numbers, and wherein at
least two uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal, and wherein each of the at least
one control timing configuration number is one of the plurality of
uplink-downlink configuration numbers; and assign the at least one
control timing configuration number to the user equipment.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 15/073,315, which was filed on Mar. 17, 2016,
which application is a continuation of U.S. application Ser. No.
13/510,201, which was filed on May 16, 2012, which is the national
stage entry under 35 U.S.C. 371 of PCT/SE2012/050093, which was
filed Jan. 31, 2012, and claims benefit of U.S. Provisional
Application No. 61/524,859 filed Aug. 18, 2011, and U.S.
Provisional Application No. 61/522,698, filed Aug. 12, 2011, the
disclosures of each of which are incorporated herein by reference
in their entirety.
TECHNICAL FIELD
[0002] Example embodiments are directed towards a base station and
user equipment, and methods therein, for the assignment and
implementation of a control timing configuration number for control
timing in a multiple cell communications network.
BACKGROUND
Long Term Evolution Systems
[0003] Long Term Evolution (LTE) uses Orthogonal Frequency Division
Multiplexing (OFDM) in the downlink direction and a Discrete
Fourier Transform (DFT)-spread OFDM in the uplink direction. The
basic LTE downlink physical resource can thus be seen as a
time-frequency grid as illustrated in FIG. 1, where each resource
element corresponds to one OFDM subcarrier during one OFDM symbol
interval. In the time domain, LTE downlink transmissions may be
organized into radio frames of 10 ms, with each radio frame
consisting of ten equally-sized subframes of length Tsubframe=1 ms,
as illustrated in FIG. 2.
[0004] Furthermore, the resource allocation in LTE is typically
described in terms of resource blocks, where a resource block
corresponds to one slot (0.5 ms) in the time domain and 12
subcarriers in the frequency domain. Resource blocks are numbered
in the frequency domain, starting with 0 from one end of the system
bandwidth.
[0005] Downlink transmissions are dynamically scheduled, i.e., in
each subframe the base station transmits control information about
to which user equipments data is transmitted and upon which
resource blocks the data is transmitted, in the current downlink
subframe. This control signaling is typically transmitted in the
first 1, 2, 3 or 4 OFDM symbols in each subframe. A downlink system
with 3 OFDM symbols for control purposes is illustrated in FIG. 3.
The dynamic scheduling information is communicated to the user
equipments via a Physical Downlink Control Channel (PDCCH)
transmitted in the control region. After successful decoding of a
PDCCH, the user equipment shall perform reception of the Physical
Downlink Shared Channel (PDSCH) or transmission of the Physical
Uplink Shared Channel (PUSCH) according to pre-determined timing
specified in the LTE specifications.
[0006] LTE uses a Hybrid-Automatic Repeat Request (HARQ), where,
after receiving downlink data in a subframe, the user equipment
attempts to decode it and reports to the base station whether the
decoding was successful, sending an Acknowledge (ACK), or not,
sending a Non-Acknowledgement (NACK) via the Physical Uplink
Control CHannel (PUCCH). In case of an unsuccessful decoding
attempt, the base station can retransmit the erroneous data.
Similarly, the base station can indicate to the UE whether the
decoding of the PUSCH was successful, sending an ACK, or not,
sending a NACK, via the Physical Hybrid ARQ Indicator CHannel
(PHICH).
[0007] Uplink control signaling from the user equipment to the base
station may comprise (1) HARQ acknowledgements for received
downlink data; (2) user equipment reports related to the downlink
channel conditions, used as assistance for the downlink scheduling;
and/or (3) scheduling requests, indicating that a mobile user
equipment needs uplink resources for uplink data transmissions.
[0008] If the mobile user equipment has not been assigned an uplink
resource for data transmission, the L1/L2 control information, such
as channel-status reports, HARQ acknowledgments, and scheduling
requests, is transmitted in uplink resources e.g. in resource
blocks, specifically assigned for uplink L1/L2 control on Release 8
(Rel-8) PUCCH. As illustrated in FIG. 4, these uplink resources are
located at the edges of the total available transmission bandwidth.
Each such uplink resource comprises 12 "subcarriers" (one resource
block) within each of the two slots of an uplink subframe. In order
to provide frequency diversity, these frequency resources are
frequency hopping, indicated by the arrow, on the slot boundary,
i.e. one "resource" comprises 12 subcarriers at the upper part of
the spectrum within the first slot of a subframe and an equally
sized resource at the lower part of the spectrum during the second
slot of the subframe or vice versa. If more resources are needed
for the uplink L1/L2 control signaling, e.g. in case of very large
overall transmission bandwidth supporting a large number of users,
additional resources blocks can be assigned next to the previously
assigned resource blocks.
Carrier Aggregation
[0009] The LTE Release 10 (Rel-10) standard has recently been
standardized, supporting bandwidths larger than 20 MHz. One
requirement on LTE Rel-10 is to assure backward compatibility with
LTE Rel-8. This may also include spectrum compatibility. That would
imply that an LTE Rel-10 carrier, wider than 20 MHz, should appear
as a number of LTE carriers to an LTE Rel-8 user equipment. Each
such carrier can be referred to as a Component Carrier (CC). In
particular for early LTE Rel-10 deployments it can be expected that
there will be a smaller number of LTE Rel-10-capable user
equipments compared to many LTE legacy user equipments. Therefore,
it may be useful to assure an efficient use of a wide carrier also
for legacy user equipments, i.e. that it is possible to implement
carriers where legacy user equipments can be scheduled in all parts
of the wideband LTE Rel-10 carrier. The straightforward way to
obtain this would be by means of Carrier Aggregation (CA). CA
implies that an LTE Rel-10 user equipment can receive multiple CCs,
where the CCs have, or at least the possibility to have, the same
structure as a Rel-8 carrier. CA is illustrated in FIG. 5.
[0010] The number of aggregated CCs as well as the bandwidth of the
individual CCs may be different for uplink and downlink. A
symmetric configuration refers to the case where the number of CCs
in downlink and uplink is the same whereas an asymmetric
configuration refers to the case that the number of CCs is
different. It should be noted that the number of CCs configured in
a cell may be different from the number of CCs seen by a user
equipment. A user equipment may for example support more downlink
CCs than uplink CCs, even though the network is configured with the
same number of uplink and downlink CCs.
[0011] During an initial access, a LTE Rel-10 user equipment
behaves similarly to a LTE Rel-8 user equipment. Upon successful
connection to the network a user equipment may--depending on its
own capabilities and the network--be configured with additional CCs
for uplink and downlink. Configuration is based on the Radio
Resource Control (RRC). Due to the heavy signaling and rather slow
speed of RRC signaling it is envisioned that a user equipment may
be configured with multiple CCs even though not all of them are
currently used. If a user equipment is configured on multiple CCs
this would imply it has to monitor all downlink CCs for PDCCH and
PDSCH. This implies a wider receiver bandwidth, higher sampling
rates, etc., resulting in high power consumption.
[0012] To mitigate the above described problems, LTE Rel-10
supports activation of CCs on top of configuration. The user
equipment monitors only configured and activated CCs for PDCCH and
PDSCH. Since activation is based on Medium Access Control (MAC)
control elements, which are faster than RRC signaling,
activation/de-activation can follow the number of CCs that are
required to fulfill the current data rate needs. Upon arrival of
large data amounts multiple CCs are activated, used for data
transmission, and de-activated if not needed anymore. All but one
CC, the Downlink (DL) Primary CC (DL PCC), may be de-activated.
Therefore, activation provides the possibility to configure
multiple CC but only activate them on a need-to basis. Most of the
time a user equipment would have one or very few CCs activated
resulting in a lower reception bandwidth and thus battery
consumption.
[0013] Scheduling of a CC may be done on the PDCCH via downlink
assignments. Control information on the PDCCH may be formatted as a
Downlink Control Information (DCI) message. In Rel-8 a user
equipment may only operate with one downlink and one uplink CC. The
association between downlink assignment, uplink grants and the
corresponding downlink and uplink CCs is therefore clear. In Rel-10
two modes of CA should be distinguished. A first mode is very
similar to the operation of multiple Rel-8 CC, a downlink
assignment or uplink grant contained in a DCI message transmitted
on a CC is either valid for the downlink CC itself or for
associated (either via cell-specific or user equipment specific
linking) uplink CC. A second mode of operation augments a DCI
message with the Carrier Indicator Field (CIF). A DCI comprising a
downlink assignment with CIF is valid for that downlink CC indicted
with CIF and a DCI comprising an uplink grant with CIF is valid for
the indicated uplink CC.
[0014] DCI messages for downlink assignments comprise among others
resource block assignment, modulation and coding scheme related
parameters, HARQ redundancy version, etc. In addition to those
parameters that relate to the actual downlink transmission, most
DCI formats for downlink assignments also comprise a bit field for
Transmit Power Control (TPC) commands. These TPC commands are used
to control the uplink power control behavior of the corresponding
PUCCH that is used to transmit the HARQ feedback.
[0015] In Rel-10 LTE, the transmission of PUCCH is mapped onto one
specific uplink CC, the Uplink (UL) Primary CC (UL PCC). User
equipments configured with a single downlink CC (which is then the
DL PCC) and uplink CC (which is then the UL PCC) are operating
dynamic ACK/NACK on PUCCH according to Rel-8. The first Control
Channel Element (CCE) used to transmit PDCCH for the downlink
assignment determines the dynamic ACK/NACK resource on Rel-8 PUCCH.
Since only one downlink CC is cell-specifically linked with the UL
PCC, no PUCCH collisions can occur since all PDCCH are transmitted
using different first CCE.
[0016] Upon reception of downlink assignments on a single Secondary
CC (SCC) or reception of multiple DL assignments, CA PUCCH should
be used. A downlink SCC assignment alone is untypical. The
scheduler in the base station should strive to schedule a single
downlink CC assignment on the DL PCC and try to de-activate SCCs if
not needed. A possible scenario that may occur is that the base
station schedules user equipment on multiple downlink CCs including
the PCC. If the user equipment misses all but the DL PCC assignment
it will use Rel-8 PUCCH instead of CA PUCCH. To detect this error
case the base station has to monitor both the Rel-8 PUCCH and the
CA PUCCH.
[0017] In Rel-10 LTE, the CA PUCCH format is based on the number of
configured CCs. Configuration of CCs is based on RRC signaling.
After successful reception/application of the new configuration a
confirmation message is sent back making RRC signaling very
safe.
Time Division Duplex
[0018] Transmission and reception from a node, e.g. user equipment
in a cellular system such as LTE, can be multiplexed in the
frequency domain or in the time domain (or combinations thereof).
Frequency Division Duplex (FDD) as illustrated to the left in FIG.
6 implies that downlink and uplink transmissions take place in
different, sufficiently separated, frequency bands. Time Division
Duplex (TDD), as illustrated to the right in FIG. 6, implies that
downlink and uplink transmissions take place in different,
non-overlapping time slots. Thus, TDD can operate in unpaired
spectrum, whereas FDD requires paired spectrum.
[0019] Typically, the structure of the transmitted signal in a
communication system is organized in the form of a frame structure.
For example, LTE uses ten equally-sized subframes of length 1 ms
per radio frame as illustrated in FIG. 7.
[0020] In the case of FDD operation (upper part of FIG. 7), there
are two carrier frequencies, one for uplink transmission (fUL) and
one for downlink transmission (fDL). At least with respect to the
user equipment in a cellular communication system, FDD can be
either full duplex or half duplex. In the full duplex case, a user
equipment can transmit and receive simultaneously, while in
half-duplex operation, the user equipment cannot transmit and
receive simultaneously (the base station is capable of simultaneous
reception/transmission though, e.g. receiving from one user
equipment while simultaneously transmitting to another user
equipment). In LTE, a half-duplex user equipment is
monitoring/receiving in the downlink except when explicitly being
instructed to transmit in a certain subframe.
[0021] In the case of TDD operation (lower part of FIG. 7), there
may be only a single carrier frequency and uplink and downlink
transmissions are typically separated in time on a cell basis. As
the same carrier frequency is used for uplink and downlink
transmission, both the base station and the mobile user equipments
need to switch from transmission to reception and vice versa. An
aspect of any TDD system is to provide the possibility for a
sufficiently large guard time where neither downlink nor uplink
transmissions occur. This is required to avoid interference between
uplink and downlink transmissions. For LTE, this guard time is
provided by special subframes (subframe 1 and, in some cases,
subframe 6), which are split into three parts: a downlink part, a
Downlink Pilot Time Slot (DwPTS), a guard period (GP), and an
uplink part, an Uplink Pilot Time Slot (UpPTS). The remaining
subframes are either allocated to uplink or downlink
transmission.
SUMMARY
[0022] An object of some of the example embodiments presented
herein is to provide an efficient means of assigning
uplink-downlink configurations across all aggregated CCs.
Accordingly, some of the example embodiments may be directed
towards a method, in a base station, for configuring control timing
to and from a user equipment in a multiple cell communications
network. The method comprises determining at least one timing
configuration number for a plurality of aggregated cells of the
multiple cell communications network. Each aggregated cell is
associated with an uplink-downlink configuration number, where at
least two uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal. The plurality of aggregated cells
is associated with the user equipment. The method also comprises
assigning the at least one timing configuration number to the user
equipment.
[0023] Some of the example embodiments may be directed towards a
base station for configuring control timing to and from a user
equipment in a multiple cell communications network. The base
station comprises a determination unit configured to determine at
least one timing configuration number for a plurality of aggregated
cells of the multiple cell communications network. Each aggregated
cell is associated with an uplink-downlink configuration number. At
least two uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal. The plurality of aggregated cells
is associated with the user equipment. The base station also
comprises an assignment unit configured to assign the at least one
timing configuration number to the user equipment.
[0024] Some of the example embodiments may be directed towards a
method, in a user equipment, for a configuration of control timing
for a user equipment in a multiple cell communications network. The
method comprises receiving, from a base station, at least one
timing configuration number for a plurality of aggregated cells of
the multiple cell communications network. Each aggregated cell is
associated with an uplink-downlink configuration number, and where
at least two uplink-downlink configuration numbers of the plurality
of aggregated cells are not equal. The plurality of aggregated
cells is associated with the user equipment. The method also
comprises implementing control timing based on the at least one
timing configuration number.
[0025] Some of the example embodiments may be directed towards a
user equipment, for a configuration of control timing for a user
equipment in a multiple cell communications network. The user
equipment comprises a determining unit configured to receive, from
a base station, at least one timing configuration number for a
plurality of aggregated cells of the multiple cell communications
network, where each aggregated cell is associated with an
uplink-downlink configuration number, and where at least two
uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal. The plurality of aggregated cells
is associated with the user equipment. The user equipment also
comprises an implementation unit configured to implement control
timing based on the at least one timing configuration number.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The foregoing will be apparent from the following more
particular description of the example embodiments, as illustrated
in the accompanying drawings in which like reference characters
refer to the same parts throughout the different views. The
drawings are not necessarily to scale, emphasis instead being
placed upon illustrating the example embodiments.
[0027] FIG. 1 is an illustrative example of a LTE downlink physical
resource;
[0028] FIG. 2 is a schematic of a LTE time-domain structure;
[0029] FIG. 3 is an illustration of a downlink subframe;
[0030] FIG. 4 is an illustrative example of an uplink L1/L2 control
signalling transmission on Rel-8 PUCCH;
[0031] FIG. 5 is an illustrative example of carrier
aggregation;
[0032] FIG. 6 is an illustrative example of frequency and
time-division duplex;
[0033] FIG. 7 is a schematic of an uplink-downlink time/frequency
structure for LTE for the case of FDD and TDD;
[0034] FIG. 8 is a schematic of different downlink/uplink
configurations for the case of TDD;
[0035] FIG. 9 is an illustrative example of uplink-downlink
interference in TDD;
[0036] FIG. 10 is an illustration of PDSCH A/N feedback timings for
a configuration 1 cell and a configuration 2 cell;
[0037] FIG. 11 is an illustration of PUSCH grant and A/N feedback
timings for a configuration 1 cell and a configuration 2 cell;
[0038] FIG. 12 is an illustration of PDSCH A/N feedback timings for
a configuration 1 cell and a configuration 3 cell;
[0039] FIG. 13 is an illustration of PUSCH grant and A/N feedback
timings for a configuration 1 cell and a configuration 3 cell;
[0040] FIG. 14 is an illustrative example of carrier aggregation of
TDD cells with different uplink-downlink configurations;
[0041] FIG. 15 is an illustrative example of subframe compatibility
hierarchy, according to some of the example embodiments;
[0042] FIG. 16 is an illustration of PUSCH grant and A/N feedback
timings for aggregation of a configuration 1 cell as Pcell and a
configuration 2 cell as Scell, according to some of the example
embodiments;
[0043] FIG. 17 is an illustration of PUSCH grant and A/N feedback
timings for aggregation of a configuration 2 cell as Pcell and a
configuration 1 cell as Scell, according to some of the example
embodiments;
[0044] FIG. 18 is an illustration of PDSCH A/N feedback timings for
aggregation of a configuration 1 cell and a configuration 2 cell,
according to some of the example embodiments;
[0045] FIG. 19 is an illustration of PUSCH grant and A/N feedback
timings for aggregation of a configuration 1 cell as Pcell and a
configuration 3 cell as Scell, according to some of the example
embodiments;
[0046] FIG. 20 is an illustration of PUSCH grant and A/N feedback
timings for aggregation of a configuration 3 cell as Pcell and a
configuration 1 cell as Scell, according to some of the example
embodiments;
[0047] FIG. 21 is an illustration of PDSCH A/N feedback timings for
aggregation of a configuration 1 cell and a configuration 3 cell,
according to some of the example embodiments;
[0048] FIG. 22 is an illustrative example of the timing of
additional forward-subframe DL scheduling PDCCHs in support of
half-duplex UEs with aggregation of a configuration 1 cell and a
configuration 2 cell, according to some of the example
embodiments;
[0049] FIG. 23 is an illustrative example of the timing of
additional forward-subframe DL scheduling PDCCHs in support of
half-duplex UEs with aggregation of a configuration 1 cell and a
configuration 3 cell, according to some of the example
embodiments;
[0050] FIG. 24 is an illustrative example of the timing of
additional cross-carrier forward-subframe DL scheduling PDCCHs in
support of full-duplex UEs with aggregation of a configuration 1
cell as Pcell and a configuration 2 cell as Scell, according to
some of the example embodiments;
[0051] FIG. 25 is an illustrative example of the timing of
additional cross-carrier forward-subframe DL scheduling PDCCHs in
support of full-duplex UEs with aggregation of a configuration 1
cell and a configuration 3 cell, according to some of the example
embodiments;
[0052] FIG. 26 is a schematic of a base station configured to
perform the example embodiments described herein;
[0053] FIG. 27 is a schematic of a user equipment configured to
perform the example embodiments described herein
[0054] FIG. 28 is a flow diagram depicting example operations of
the base station of FIG. 26; and
[0055] FIG. 29 is a flow diagram depicting example operations of
the user equipment of FIG. 27.
DETAILED DESCRIPTION
[0056] In the following description, for purposes of explanation
and not limitation, specific details are set forth, such as
particular components, elements, techniques, etc. in order to
provide a thorough understanding of the example embodiments.
However, the example embodiments may be practiced in other manners
that depart from these specific details. In other instances,
detailed descriptions of well-known methods and elements are
omitted so as not to obscure the description of the example
embodiments.
[0057] As part of the development of the example embodiments
presented herein, a problem will first be identified and discussed.
TDD allows for different asymmetries in terms of the amount of
resources allocated for uplink and downlink transmission,
respectively, by means of different downlink/uplink configurations.
In LTE, there are seven different configurations as shown in FIG.
8. Note that in the description below, under the heading `TDD HARQ
Timing`, a downlink subframe may mean either downlink or the
special subframe.
[0058] To avoid severe interference between downlink and uplink
transmissions between different cells, neighbor cells should have
the same downlink/uplink configuration. If this is not done, uplink
transmission in one cell may interfere with downlink transmission
in the neighboring cell and vice versa as illustrated in FIG. 9.
Hence, the downlink/uplink asymmetry may typically not vary between
cells, but is signaled as part of the system information and
remains fixed for a long period of time.
[0059] The description provided herein is arranged as follows.
First, an overview of current systems and methods for control
timing configuration is presented under the heading `Existing
Systems--TDD HARQ Control Timing`. Thereafter, limitations of the
existing systems are explored under the subheading `Problems with
Existing Solutions`.
[0060] A basis for the example embodiments is thereafter presented
in the section entitled `Subframe Timing Compatibility`, where
complex configuration tables (explained in `Existing Systems--TDD
HARQ Control Timing`) may be replaced with the use of a subframe
timing compatibility hierarchy. Thereafter, examples of control
timing configuration assignment, utilizing the subframe timing
compatibility hierarchy, are provided in the sub-section entitled
`Configuration Assignment`. Examples of control timing
configuration assignment based on an ordered listing of the
subframe timing compatibility hierarchy is provided in the
sub-section `Computation of the Subframe Timing Compatibility based
on Efficient Storage.`
[0061] Thereafter, examples of control timing configuration
assignment of user equipments utilizing a half-duplex mode of
operation are provided in the sub-section `Examples of Half-Duplex
Configuration Assignment`. Similarly, examples of control timing
configuration assignment of user equipments utilizing a full-duplex
mode of operation are provided in the sub-section `Examples of
Full-Duplex Configuration Assignment`. Thereafter examples of
forward downlink scheduling with respect to user equipments with
full and half-duplex modes of operation is provided under the
sub-heading `Examples of Forward Downlink Scheduling`.
[0062] Finally, examples of network node configurations and example
operations of such nodes are presented under the sub-headings
`Example Node Configurations` and `Example Node Operations`. It
should be appreciated that the example node operations provide a
generalized explanation of node operations which may encompass all
of the examples provided in the foregoing sub-headings which are
not related to existing systems.
Existing Systems--TDD HARQ Control Timing
[0063] The timings for HARQ ACK/NACK (A/N) feedbacks for the PUSCH
and the PDSCH as well as the grant of PUSCH may be specified with
extensive tables and procedure descriptions for each
uplink-downlink configuration.
[0064] For TDD UL/DL (U/D) configurations 1-6 and normal HARQ
operation, the user equipment shall upon detection of a PDCCH with
an uplink DCI format and/or a PHICH transmission in subframe n
intended for the user equipment, adjust the corresponding PUSCH
transmission in subframe n+k, with k given in Table 1, shown below,
according to the PDCCH and PHICH information.
TABLE-US-00001 TABLE 1 PUSCH grant timing k for TDD configurations
0-6 TDD U/D subframe number n Configuration 0 1 2 3 4 5 6 7 8 9 0 4
6 4 6 1 6 4 6 4 2 4 4 3 4 4 4 4 4 4 5 4 6 7 7 7 7 5
[0065] For TDD U/D configuration 0 and normal HARQ operation the
user equipment shall upon detection of a PDCCH with uplink DCI
format and/or a PHICH transmission in subframe n intended for the
user equipment, adjust the corresponding PUSCH transmission in
subframe n+k if the Most Significant Bit (MSB) of the UL index in
the PDCCH with uplink DCI format is set to 1 or PHICH is received
in subframe n=0 or 5 in the resource corresponding to
I.sub.PHICH=0, with k given in Table 1. If, for TDD U/D
configuration 0 and normal HARQ operation, the Least Significant
Bit (LSB) of the UL index in the DCI format 0/4 is set to 1 in
subframe n or a PHICH is received in subframe n=0 or 5 in the
resource corresponding to I.sub.PHICH=1, or PHICH is received in
subframe n=1 or 6, the user equipment shall adjust the
corresponding PUSCH transmission in subframe n+7. If, for TDD U/D
configuration 0, both the MSB and LSB of the UL index in the PDCCH
with uplink DCI format are sent in subframe n, the user equipment
shall adjust the corresponding PUSCH transmission in both subframes
n+k and n+7, with k given in Table 1.
[0066] For PUSCH transmissions scheduled from a serving cell c in
subframe n, a user equipment shall determine the corresponding
PHICH resource of serving cell c in subframe n+k.sub.PHICH, where
k.sub.PHICH is given in Table 2, provided below, for TDD. For
subframe bundling operation, the corresponding PHICH resource is
associated with the last subframe in the bundle.
TABLE-US-00002 TABLE 2 k.sub.PHICH for TDD TDD U/D subframe index n
Configuration 0 1 2 3 4 5 6 7 8 9 0 4 7 6 4 7 6 1 4 6 4 6 2 6 6 3 6
6 6 4 6 6 5 6 6 4 6 6 4 7
[0067] The user equipment shall also feedback PDSCH decoding A/N
information in pre-defined UL subframes. The user equipment shall
transmit such a HARQ A/N response on the PUCCH in UL subframe, if
there is PDSCH transmission indicated by the detection of
corresponding PDCCH or there is PDCCH indicating downlink SPS
release within subframe(s) n-k, where k is within the association
set K={k.sub.0, k.sub.1, . . . k.sub.M-1} listed in Table 3,
provided below.
TABLE-US-00003 TABLE 3 Downlink association set index K: {k=hd 0,
k.sub.1, . . . k.sub.M-1} for TDD UL-DL Subframe n Configuration 0
1 2 3 4 5 6 7 8 9 0 6 4 6 4 1 7, 6 4 7, 6 4 2 8, 7, 8, 7, 4, 6 4, 6
3 7, 6, 6, 5 5, 4 11 4 12, 8, 6, 5, 7,11 4, 7 5 13, 12, 9, 8, 7, 5,
4, 11, 6 6 7 7 5 7 7
[0068] In LTERel-10, all HARQ control timings are determined based
on the Primary-cell (Pcell) configuration number as discussed
above. The determination of HARQ operations in LTERel-10 work only
if all aggregated TDD cells have an identical U/D configuration.
However, when developing the example embodiments presented herein
it has been discovered that a straightforward extension of this
operation for aggregation of different U/D configurations proves
difficult.
[0069] Consider the PDSCH A/N feedback timing example for
aggregating a configuration 1 cell and a configuration 2 cell
illustrated in FIG. 10. In FIG. 10, U represents uplink subframes,
D represents downlink subframes, and S represents special subframes
which may be used for both uplink and downlink. It should be
appreciated that for the purpose of simplicity, the S subframes
will be treated as downlink subframes in the examples provided
herein.
[0070] If the configuration 2 cell is the Pcell, A/N feedback for
the configuration 1 Secondary-cell (Scell) PDSCH may be fed-back
based on the timing rules of Pcell. However, if the configuration 1
cell is the Pcell, there will be no A/N feedback timing rules for
subframes 3 and 8 in the configuration 2 Scell.
[0071] Consider the PUSCH grant and A/N feedback timing example for
aggregating a configuration 1 cell and a configuration 2 cell
illustrated in FIG. 11. If the configuration 1 cell is the Pcell,
PUSCH grant and A/N feedback for the configuration 2 Scell can be
fed-back based on the timing rules of Pcell. However, if the
configuration 2 cell is the Pcell, PUSCH cannot be scheduled for
subframe 3 and 8 in configuration 1 Scell because there is no such
UL grant timing in configuration 2. Note that A/N feedback timing
rules for these two subframes are not available, either.
[0072] The control timing problems may be even more severe than the
examples discussed above. In the case of aggregating a
configuration 1 and a configuration 3 cells, the HARQ control
timings don't work regardless of which configuration is the
Pcell.
[0073] More specifically, consider the PDSCH A/N feedback timing
illustrated in FIG. 12: [0074] If configuration 1 is the Pcell,
PDSCH A/N for subframes 7 & 8 of the configuration 3 Scell
cannot be fed back. [0075] If configuration 3 is the Pcell, PDSCH
A/N for subframe 4 of the configuration 1 Scell cannot be fed
back.
[0076] Further, consider the PUSCH grant and A/N feedback timing
illustrated in FIG. 13: [0077] If configuration 1 is the Pcell,
PUSCH for subframe 4 in configuration 3 Scell cannot be scheduled.
[0078] If configuration 3 is the Pcell, PUSCH for subframe 7 &
8 in configuration 1 Scell cannot be scheduled.
Problems with Existing Systems
[0079] The following are examples of some of the problems with
existing solutions, which have been recognized when developing the
embodiments presented herein. In Rel-10, carrier aggregation of TDD
cells is specified with the restriction that the U/D configurations
for all the aggregated cells are identical. There is a need to
allow more flexible carrier aggregation of TDD cells is to be
addressed in Rel-11 of LTE.
[0080] As discussed above, the U/D configurations of neighboring
cells need to be compatible to avoid severe interference problems.
However, there are cases where the neighboring cells are operated
by different operators or different wireless systems. The LTE TDD
cells adjacent to those neighboring systems are hence required to
adopt certain compatible U/D configurations. As a result, an
operator may have several TDD cells having different U/D
configurations on different frequencies as illustrated in FIG.
14.
[0081] A further complication from such aggregation cases is that
the nominally TDD user equipment may be required to transmit and
receive simultaneously in certain subframes (such as subframe 7 and
8 in FIG. 14). Such FDD-like operations are incompatible with
existing designs of TDD user equipments. To enable such full-duplex
operations in Rel-11 may impose additional user equipment
complexity and costs. It is therefore necessary to also consider
possible half-duplex operations during such conflicting subframes.
That is, the user equipment should be instructed to perform either
reception or transmission but not both during such conflicting
subframes.
[0082] To circumvent problems such those identified in the above,
adding additional HARQ control timing rules based on specific
aggregation cases may be performed. In additional to the existing
timing rules for seven TDD configurations,
( 7 2 ) = 2 .times. 1 ##EQU00001##
additional sets of rules may be added to specify the HARQ behaviors
for every possible pair of heterogeneous configuration. On top of
these, additional specification for aggregation of three different
U/D configurations may also be introduced. Apparently, specifying
these additional rules for supporting aggregation of different U/D
configurations will substantially increase the LTE complexity and
implementation costs.
Subframe Timing Compatibility
[0083] To enable a systematic solution to a plurality of
aggregation scenarios with different TDD U/D configurations,
according to some of the example embodiments, a subframe timing
compatibility is designed and illustrated in FIG. 15. The subframe
timing compatibility is a hierarchy that may be encoded as look-up
tables, a linked list or a plurality of digital representations
suitable for storage in communication devices.
[0084] The subframe timing compatibility hierarchy may be designed
with the following principles:
[0085] (1) The UL subframes in a TDD configuration are also UL
subframes in those TDD configurations that can be corrected with
upward arrows.
[0086] For example, subframes 2 and 3 are UL subframes in
configuration 4. These two subframes are also UL in configurations
3, 1, 6 and 0, all of which can be connected from configuration 4
with upward arrows. As a second example, subframes 2 and 7 are UL
subframes in configuration 2. These two subframes are not both UL
in configuration 3 because there is no upward arrow connecting the
two configurations.
[0087] (2) The DL subframes in a TDD configuration are also DL
subframes in those TDD configurations that can be corrected with
downward arrows.
[0088] For example, subframe 0, 1, 5, 6 and 9 are DL subframes in
configuration 6. These five subframes are also DL in configurations
1, 2, 3, 4 and 5, all of which can be connected from configuration
6 with downward arrows. As a second example, subframe 7 is a DL
subframe in configuration 3 but not a DL subframe in configuration
2 because there is no downward arrow connecting the two
configurations.
[0089] With these design properties, the subframe timing
compatibility hierarchy may provide the following utility: [0090]
(1) Given a set of TDD configurations to be aggregated, a TDD
configuration that can be connected from all of the given TDD
configurations with upward arrows has the following two properties:
[0091] The TDD configuration comprises UL subframes that are a
superset of all UL subframes from all given TDD configurations.
[0092] The TDD configuration comprises DL subframes that are
available in all given TDD configurations.
Example One
[0093] Given TDD configuration 1 and 2, all subframes that are UL
in either configuration 1 or 2 are also UL subframes in
configuration 1, 6 and 0. The DL subframes in configuration 1, 6 or
0 are also DL subframes in configuration 1 and 2.
[0094] Given TDD configuration 1 and 3, all subframes that are UL
in either configuration 1 or 3 are also UL in configuration 6 and
0. The DL subframes in configuration 6 or 0 are also DL subframes
in configuration 1, 2, 3, 4, 5 and 6.
[0095] Given TDD configuration 2, 3 and 4, all subframes that are
UL in any of the three configurations are also UL in configuration
6 and 0. The DL subframes in configuration 6 or 0 are also DL
subframes in configuration 1, 2, 3, 4, 5 and 6.
[0096] Given a set of TDD configurations, a TDD configuration that
can be connected from all of the given TDD configurations with
downward arrows has the following two properties: [0097] The TDD
configuration comprises DL subframes that are a superset of all DL
subframes from all given TDD configurations. [0098] The TDD
configuration comprises UL subframes that are available in all
given TDD configurations.
Example Two
[0099] Given TDD configuration 1 and 2, all subframes that are DL
in either configuration 1 or 2 are also DL in configuration 2 and
5. The UL subframes in configuration 2 or 5 are also UL subframes
in configuration 1, 2, 6 and 0.
[0100] Given TDD configuration 1 and 3, all subframes that are DL
in either configuration 1 or 3 are also DL in configuration 4 and
5. The UL subframes in configuration 4 or 5 are also UL subframes
in configuration 0, 3, 4 and 6.
[0101] Given TDD configuration 2, 3 and 4, all subframes that are
DL in any of the three configurations are also DL in configuration
5. The UL subframes in configuration 5 are also UL subframes in
configuration 0, 1, 2, 3, 4 and 6.
Configuration Assignment
[0102] In Rel-8 TDD, the following two sets of subframe timings are
set based on the same parameter, which is the serving cell U/D
configuration number: (1) UL HARQ control and grant subframe
timing, and (2) DL HARQ A/N subframe timing. In Rel-10 TDD CA, both
types of subframe timings across all cells are set based on the
same parameter, which is the Pcell U/D configuration number.
[0103] To support carrier aggregation of TDD cells with different
U/D configurations, the user equipment may be configured with the
following two numbers according to the teaching of the example
embodiments: (1) an UL control timing configuration number for
setting UL HARQ and grant timings across all aggregated cells, and
(2) a DL HARQ control timing configuration number for setting DL
HARQ timings across all aggregated cells.
[0104] The UL control timing configuration number may be set to the
configuration number of a configuration that can be connected from
all aggregated configurations with upward arrows in the subframe
timing compatibility hierarchy in FIG. 15. If more than one
configuration number can be chosen, the chosen setting may be the
configuration at the lowest level in the subframe timing
compatibility hierarchy. The chosen setting may result in more DL
subframes for PUSCH grant and A/N feedback. The following example
cases are provided below for the purpose of explaining some of the
example embodiments.
Example Case 1
[0105] If cells with configuration 1 and 2 are aggregated, the UL
control timing configuration number can be set to 1, 6 or 0. The
chosen setting may be 1.
Example Case 2
[0106] If cells with configuration 1 and 3 are aggregated, the UL
control timing configuration number can be set to 6 or 0. The
chosen setting may be 6, which is different than the U/D
configuration numbers of the two TDD cells.
[0107] This UL control timing configuration number setting ensures
identical PUSCH grant and PHICH timings across all CCs and DL
subframes are available at these timings regardless of the Pcell
configuration. That is, the PUSCH grant and PHICH subframes are
never in subframes with conflicting U/D directions across different
CCs. This setting further ensures all UL subframes from all
aggregated CCs can be scheduled either in-CC or cross-CC.
[0108] The DL HARQ control timing configuration number may be set
to the configuration number of a configuration that can be
connected from all aggregated configurations with downward arrows
in the subframe timing compatibility hierarchy in FIG. 15. If more
than one configuration number can be chosen, the chosen setting may
be that of the configuration at the highest level in the subframe
timing compatibility hierarchy. The chosen setting may result in
more UL subframes for PDSCH A/N feedback. The following example
cases are provided below for the purpose of explaining some of the
example embodiments.
Example Case 1
[0109] If cells with configuration 1 and 2 are aggregated, the DL
HARQ control timing configuration number can be set to 2 or 5. The
chosen setting may be 2.
Example Case 2
[0110] If cells with configuration 1 and 3 are aggregated, the DL
HARQ control timing configuration number can be set to 4 or 5. The
chosen setting may be 4, which is different than the U/D
configuration numbers of the two TDD cells.
[0111] This DL HARQ control timing configuration number setting
ensures identical PDSCH A/N feedback timings across all CCs and UL
subframes are available at these timings regardless of the Pcell
configuration.
Example Carrier Aggregation of Configuration 1 and 2 TDD Cells
[0112] To support the aggregation of configuration 1 and 2 TDD
cells, the two HARQ control timing configuration numbers may be set
as follows: [0113] The UL control timing configuration number may
be set to 1. [0114] The DL HARQ control timing configuration number
may be set to 2.
[0115] Note these configuration number settings are applicable
regardless of which of the two TDD cells serves as the Pcell.
[0116] The PUSCH grant and A/N feedback timings for aggregation of
a configuration 1 cell as Pcell and a configuration 2 cell as Scell
are illustrated in FIG. 16. The PUSCH grant and A/N feedback
timings for aggregation of a configuration 2 cell as Pcell and a
configuration 1 cell as Scell are illustrated in FIG. 17. This
analysis shows that all the UL subframes can be scheduled either
from the Pcell (if cross-carrier scheduling is configured) or from
the Scell itself (if cross-carrier scheduling is not configured).
Furthermore, A/N feedback timings for all UL subframes are clearly
assigned.
[0117] The PDSCH A/N feedback timings for aggregation of a
configuration 1 cell and a configuration 2 cell is shown in FIG.
18. The analysis confirms that A/N feedbacks for all PDSCH in both
the Pcell and the Scell are clearly assigned to suitable UL
subframes on the Pcell.
Example Carrier Aggregation of Configuration 1 and 3 TDD Cells
[0118] To support the aggregation of configuration 1 and 3 TDD
cells, the two HARQ control timing configuration numbers may be set
as follows: [0119] The UL control timing configuration number may
be set to 6. [0120] The DL HARQ control timing configuration number
may be set to 4.
[0121] Note these configuration number settings are applicable
regardless of which of the two TDD cells serves as the Pcell.
[0122] The PUSCH grant and A/N feedback timings (i.e., for uplink
A/N feedback timing) for aggregation of a configuration 1 cell as
Pcell and a configuration 3 cell as Scell are illustrated in FIG.
19. The PUSCH grant and A/N feedback timings for aggregation of a
configuration 3 cell as Pcell and a configuration 1 cell as Scell
are illustrated in FIG. 20. This analysis shows that all the UL
subframes can be scheduled either from the Pcell (if cross-carrier
scheduling is configured) or from the Scell itself (if
cross-carrier scheduling is not configured). Furthermore, A/N
feedback timings for all UL subframes are clearly assigned.
[0123] The PDSCH A/N feedback timings for aggregation of a
configuration 1 cell and a configuration 3 cell is shown in FIG.
21. The analysis confirms that A/N feedbacks for all PDSCH in both
the Pcell and the Scell are clearly assigned to suitable UL
subframes on the Pcell.
Computation of the Subframe Timing Compatibility based on Efficient
Storage
[0124] As should be appreciated from above, according to some of
the example embodiments, for a given set of aggregated TDD cells
with different U/D configurations, the UL control and DL HARQ
control timing configuration numbers may be set based on a
systematic rule encoded in the subframe timing compatibility
hierarchy, for example as illustrated in FIG. 15. The UL control
and DL HARQ control timing configuration numbers so chosen may be
different than any of the U/D configuration number of the
aggregated cells.
[0125] The UL control timing configuration number may be set to the
configuration number of a configuration that can be connected from
all aggregated configurations with upward arrows in the subframe
timing compatibility hierarchy in FIG. 15. If more than one
configuration number can be chosen, a setting may be chosen to be
the configuration at the lowest level in the subframe compatibility
hierarchy. This setting results in more DL subframes for PUSCH
grant and A/N feedback.
[0126] The DL HARQ control timing configuration number may be set
to the configuration number of a configuration that can be
connected from all aggregated configurations with downward arrows
in the subframe timing compatibility hierarchy in FIG. 15. If more
than one configuration number can be chosen, the setting may be
chosen to be the configuration at the highest level in the subframe
timing compatibility hierarchy. This setting results in more UL
subframes for PDSCH A/N feedback.
[0127] Some of the example embodiments may also be directed towards
efficient digital representation and storage methods of the
subframe timing compatibility hierarchy. Some of the example
embodiments may also be directed towards efficient computational
methods and a corresponding apparatus for computing the UL control
timing configuration number and the DL HARQ control timing
configuration number.
[0128] According to some of the example embodiments, the subframe
timing compatibility hierarchy may be represented with a table of
sets. The UL control timing configuration number and the DL HARQ
control timing configuration number may be computed with set
intersection operations. If there is more than one control timing
configuration number candidates after the set intersection
operations, the network node can select a preferred control timing
configuration number setting based on at least system loads and
user equipment application needs.
[0129] An UL control timing configuration candidate set and a DL
HARQ control timing configuration candidate set may be stored for
each of the LTE cell U/D configurations. An example of the specific
values of the candidate sets are shown in the table provided
below.
TABLE-US-00004 TABLE 4 Control Timing Configuration Sets Component
UL control timing DL HARQ control cell U/D configuration timing
configuration configuration candidate set candidate set 0 {0} {0,
6, 1, 3, 2, 4, 5} 1 {1, 6, 0} {1, 2, 4, 5} 2 {2, 1, 6, 0} {2, 5} 3
{3, 6, 0} {3, 4, 5} 4 {4, 1, 3, 6, 0} {4, 5} 5 {5, 2, 4, 1, 3, 6,
0} {5} 6 {6, 0} {6, 1, 3, 2, 4, 5}
[0130] According to some of the example embodiments, for a given
set of cell U/D configurations to be aggregated, the UL control
timing configuration number may be set to a configuration number
from the intersection of all UL control timing configuration
candidate sets corresponding to the cell U/D configurations to be
aggregated. The following example cases are provided below for the
purpose of explaining some of the example embodiments.
Example Case 1
[0131] If cells with configuration 1 and 2 are aggregated, the
corresponding UL control timing configuration candidate sets may be
{1,6,0} and {2,1,6,0}. The intersection of all these sets can be
computed to be {1,6,0}. Therefore, the UL control timing
configuration number can be set to 1, 6 or 0.
Example Case 2
[0132] If cells with configuration 1 and 3 are aggregated, the
corresponding UL control timing configuration candidate sets may be
{1,6,0} and {3,6,0}. The intersection of all these set can be
computed to be {6,0}. Therefore, the UL control timing
configuration number can be set to 6 or 0.
Example Case 3
[0133] If cells with configuration 1, 3 and 4 are aggregated, the
corresponding UL control timing configuration candidate sets may be
{1,6,0}, {3,6,0} and {4,1,3,6,0}. The intersection of all these set
can be computed to be {6,0}. Therefore, the UL control timing
configuration number can be set to 6 or 0.
[0134] According to some of the example embodiments, for a given
set of cell U/D configurations to be aggregated, the DL HARQ
control timing configuration number may be set to a configuration
number from the intersection of all DL HARQ control timing
configuration candidate sets corresponding to the cell U/D
configurations to be aggregated. The following example cases are
provided below for the purpose of explaining some of the example
embodiments.
Example Case 1
[0135] If cells with configuration 1 and 2 are aggregated, the
corresponding DL HARQ control timing configuration candidate sets
may be {1,2,4,5} and {2,5}. The intersection of all these sets can
be computed to be {2,5}. Therefore, the DL HARQ control timing
configuration number can be set to 2 or 5.
Example Case 2
[0136] If cells with configuration 1 and 3 are aggregated, the
corresponding DL HARQ control timing configuration candidate sets
may be {1,2,4,5} and {3,4,5}. The intersection of all these sets
may be computed to be {4,5}. Therefore, the DL HARQ control timing
configuration number can be set to 4 or 5.
Example Case 3
[0137] If cells with configuration 1, 3 and 4 are aggregated, the
corresponding DL HARQ control timing configuration candidate sets
may be {1,2,4,5}, {3,4,5} and {4,5}. The intersection of all of
these sets may be computed to be {4,5}. Therefore, the DL HARQ
control timing configuration number can be set to 4 or 5.
[0138] If there are more than one control timing configuration
number candidates after the set intersection operations, the
network node or user equipment can select and signal a preferred
control timing configuration number setting based on at least
system loads and user equipment application needs. Signaling of the
control timing could for example be done with radio resource
control (RRC) signaling.
[0139] It should also be appreciated that, according to some of the
example embodiments, the subframe timing compatibility hierarchy
may be represented with a table of ordered sets. The UL control
timing configuration number and the DL HARQ control timing
configuration number may be computed with set intersection
operations while preserving the order of numbers within the set.
The chosen control timing configuration number may be the first or
last number after the set intersection operation.
[0140] An UL control timing configuration candidate set and a DL
HARQ control timing configuration candidate set may be stored for
each of the LTE cell U/D configurations. The specific values of the
candidate or ordered sets are shown in table 4. The order of
candidate configuration numbers in each of the candidate sets shown
in the table may be preserved in storage.
[0141] For a given set of cell U/D configurations to be aggregated,
the UL control timing configuration number may be set to a
configuration number from the intersection of all UL control timing
configuration candidate sets corresponding to the cell U/D
configurations to be aggregated, where the set intersection
operations preserve the ordering of numbers in the concerned sets.
The following example cases are provided below for the purpose of
explaining some of the example embodiments.
Example 1
[0142] If cells with configuration 1 and 2 are aggregated, the
corresponding UL control timing configuration candidate or ordered
sets may be {1,6,0} and {2,1,6,0}. The intersection of all these
set can be computed to be {1,6,0}. Therefore, the chosen UL control
timing configuration number may be 1.
Example 2
[0143] If cells with configuration 1 and 3 are aggregated, the
corresponding UL control timing configuration candidate or ordered
sets may be {1,6,0} and {3,6,0}. The intersection of all these set
can be computed to be {6,0}. Therefore, the chosen UL control
timing configuration number may be 6.
Example 3
[0144] If cells with configuration cells 1, 3 and 4 are aggregated,
the corresponding UL control timing configuration candidate or
ordered sets may be {1,6,0}, {3,6,0} and {4,1,3,6,0}. The
intersection of all these set can be computed to be {6,0}.
Therefore, the chosen UL control timing configuration number may be
6.
[0145] For a given set of cell U/D configurations to be aggregated,
the DL HARQ control timing configuration number may be set to a
configuration number from the intersection of all DL HARQ control
timing configuration candidate sets corresponding to the cell U/D
configurations to be aggregated, where the set intersection
operations preserve the ordering of numbers in the concerned sets.
The following example cases are provided below for the purpose of
explaining some of the example embodiments.
Example 1
[0146] If cells with configuration 1 and 2 are aggregated, the
corresponding DL HARQ control timing configuration candidate or
ordered sets may be {1,2,4,5} and {2,5}. The intersection of all
these set can be computed to be {2,5}. Therefore, the chosen DL
HARQ control timing configuration number may be 2.
Example 2
[0147] If cells with configuration 1 and 3 are aggregated, the
corresponding DL HARQ control timing configuration candidate or
ordered sets may be {1,2,4,5} and {3,4,5}. The intersection of all
these set can be computed to be {4,5}. Therefore, the chosen DL
HARQ control timing configuration number may be 4.
Example 3
[0148] If cells with configuration 1, 3 and 4 are aggregated, the
corresponding DL HARQ control timing configuration candidate sets
may be {1,2,4,5}, {3,4,5} and {4,5}. The intersection of all these
set can be computed to be {4,5}. Therefore, the chosen DL HARQ
control timing configuration number may be 4.
Examples of Half-Duplex Configuration Assignment
[0149] A user equipment capable of only half-duplex operations can
perform either transmission or reception in a subframe but not both
actions. Therefore, according to some of the example embodiments,
subframes without conflicting U/D directions can be scheduled with
PDCCH transmitted in the same subframe time (in-subframe
scheduling).
[0150] For subframes with conflicting U/D directions across CCs,
the half-duplex user equipments need to be informed of the
scheduled directions in advance. Forward-subframe UL scheduling is
already used in LTE. However, additional forward-subframe DL
scheduling PDCCHs may be needed.
[0151] According to the example embodiments, the following features
are designed for the forward-subframe DL scheduling PDCCHs: [0152]
If no cross-CC scheduling is configured, additional
forward-subframe DL scheduling PDCCHs for the individual cells may
be added (referred to as in-CC forward-subframe DL scheduling
PDCCHs). [0153] If cross-CC scheduling is configured, additional
cross-CC forward-subframe DL scheduling PDCCHs from the Pcell may
be added. [0154] The forward-scheduling timing may be based on the
UL grant timing of the same target cell. Other forward-scheduling
timing methods may also be used. [0155] The forward-subframe DL
scheduling PDCCHs can be implemented according to the teaching of
flexible carrier indicator.
Example Carrier Aggregation of Configuration 1 and 2 TDD Cells
[0156] To support the aggregation of configuration 1 and 2 TDD
cells, the two HARQ control timing configuration numbers may be set
as follows: [0157] The UL control timing configuration number may
be set to 1. [0158] The DL HARQ control timing configuration number
may be set to 2.
[0159] For subframes with conflicting U/D directions across CCs,
the half-duplex user equipments need to be informed of the
scheduled directions in advance. Additional forward-subframe DL
scheduling PDCCHs based on UL grant timings may be introduced as
follows: [0160] If configuration 1 is a Pcell and cross-CC
scheduling is configured, two additional cross-CC forward-subframe
DL scheduling PDCCHs (from the configuration 1 cell) are shown in
FIG. 22. [0161] If configuration 2 is a Pcell or if cross-CC
scheduling is not configured, two additional in-CC forward-subframe
DL scheduling PDCCHs (from the configuration 2 cell) are shown in
FIG. 22.
Example Carrier Aggregation of Configuration 1 and 3 TDD Cells
[0162] To support the aggregation of configuration 1 and 3 TDD
cells, the two HARQ control timing configuration numbers may be set
as follows: [0163] The UL control timing configuration number may
be set to 6. [0164] The DL HARQ control timing configuration number
may be set to 4.
[0165] For subframes with conflicting U/D directions across CCs,
the half-duplex UEs may need to be informed of the scheduled
directions in advance. Additional forward-subframe DL scheduling
PDCCHs based on UL grant timings may be introduced as follows:
[0166] If no cross-CC scheduling is configured, three in-CC
forward-subframe DL scheduling PDCCHs from the Pcell and Scell may
be added as shown in FIG. 23. [0167] If cross-CC scheduling is
configured, three cross-CC forward-subframe DL scheduling PDCCHs
from the Pcell may be added as shown in FIG. 23.
Examples of Full-Duplex Configuration Assignment
[0168] A full-duplex user equipment can perform transmission and
reception simultaneously in subframes with conflicting U/D
directions across different CCs. According to the above teaching of
the example embodiments, if cross-carrier scheduling is not
configured, all DL subframes can be scheduled in-CC and
in-subframe.
[0169] If cross-carrier scheduling is configured, in a subframe
without conflicting directions, the DL subframes in the scheduling
cell can carry the cross-carrier DL scheduling PDCCHs to schedule
other DL subframes of the same subframe time on other cells.
Furthermore, in a subframe with conflicting directions, if the
scheduling cell is a DL subframe, PDCCH(s) can be sent from said
subframe to schedule other DL subframes of the same subframe time
on other cells. Additionally, in a subframe with conflicting
directions, if the scheduling cell is an UL subframe, PDCCH(s)
cannot be sent from said subframe to schedule other DL subframes of
the same subframe time on other cells.
[0170] Thus, according to some of the example embodiments, cross-CC
forward-subframe DL scheduling PDCCHs from the scheduling cell may
be enabled. According to some of the example embodiments, the
cross-CC forward-subframe DL scheduling PDCCHs designed in the
example embodiments directed towards the half-duplex operations are
applied to support full-duplex operations with certain
cross-carrier scheduling scenarios.
Example Carrier Aggregation of Configuration 1 and 2 TDD Cells
[0171] To support the aggregation of configuration 1 and 2 TDD
cells, the two HARQ control timing configuration numbers may be set
as follows: [0172] The UL control timing configuration number may
be set to 1. [0173] The DL HARQ control timing configuration number
may be set to 2.
[0174] If configuration 2 is the Pcell, all DL subframes can be
scheduled in-subframe and in-CC or cross-CC.
[0175] If configuration 1 is the Pcell, if cross-CC scheduling is
not configured, all DL subframes can be scheduled in-CC and
in-subframe. If cross-scheduling is configured, all DL subframes in
the Scell can be CC-scheduled in subframe except subframes 3 and 8.
Note these two subframes are the subframes with conflicting U/D
directions. Hence, the half-duplex solution can be reused here. The
two subframes are scheduled with forward-subframe scheduling PDCCH
based on the UL grant timings of these two subframes. The two
additional cross-CC forward-subframe DL scheduling PDCCHs are shown
in FIG. 24.
Example Carrier Aggregation of Configuration 1 and 3 TDD Cells
[0176] To support the aggregation of configuration 1 and 3 TDD
cells, the two HARQ control timing configuration numbers may be set
as follows: [0177] The UL control timing configuration number may
be set to 6. [0178] The DL HARQ control timing configuration number
may be set to 4.
[0179] If cross-CC scheduling is not configured, all DL subframes
can be scheduled in-CC and in-subframe. If cross-scheduling is
configured, all DL subframes in the Scell can be CC-scheduled
in-subframe except subframes 7 and 8 in configuration 3 cannot be
cross-scheduled in-subframe if configuration 1 is the Pcell.
Additionally, subframe 4 cannot be cross-scheduled in-subframe if
configuration 3 is the Pcell.
[0180] Using the half-duplex solution from the example embodiments
directed towards half-duplex scheduling, two (if configuration 1 is
the Pcell) or one (if configuration 3 is the Pcell) additional
cross-CC forward-subframe DL scheduling PDCCHs based on the
corresponding UL grant timings are used as shown in FIG. 25.
Examples of Forward Downlink Scheduling
[0181] The forward-subframe DL scheduling PDCCHs introduced in the
example embodiments directed to half and full duplex assignment are
new features and may require implementation complexity to integrate
into existing network node hardware and software architecture.
There is hence a benefit in reducing the need to rely on such new
forward-subframe DL scheduling PDCCHs.
[0182] According to some of the example embodiments, the following
two operation rules may be implemented on the user equipment for a
subframe with conflicting directions across the aggregated CCs:
[0183] In full-duplex operations, a user equipment may monitor
PDCCH(s) in scheduling CC(s) with the DL direction (even if the
user equipment has been given in advance grant(s) to transmit in
CC(s) with the UL direction).
[0184] In half-duplex operations, a user equipment may monitor
PDCCH(s) in scheduling CC(s) with the DL direction if the user
equipment has not been given in advance any grant to transmit in
any CC with the UL direction.
Example Node Configurations
[0185] FIG. 26 illustrates an example of a base station 103 which
may incorporate some of the example embodiments discussed above. As
shown in FIG. 26, the base station 103 may comprise a receiving 302
and transmitting 304 units configured to receive and transmit,
respectively, any form of communications or control signals within
a network. It should be appreciated that the receiving 302 and
transmitting 304 units may be comprised as a single transceiving
unit. It should further be appreciated that the receiving 302 and
transmitting 304 units, or transceiving unit, may be in the form of
any input/output communications port known in the art.
[0186] The base station 103 may further comprise at least one
memory unit 308 that may be in communication with the receiving 302
and transmitting 304 units. The memory unit 308 may be configured
to store received or transmitted data and/or executable program
instructions. The memory unit 308 may also be configured to store
the timing compatibility hierarchy and/or control timing
configuration candidate or ordered sets. The memory unit 308 may be
any suitable type of computer readable memory and may be of
volatile and/or non-volatile type.
[0187] The base station 103 further comprises a determination unit
308 which is configured to determine at least one timing
configuration number for a plurality of aggregated cells. The base
station further comprises an assignment unit 310 which is
configured to assign the uplink-downlink configuration to a user
equipment 101.
[0188] The determination unit 308 and/or the assignment unit 310
may be any suitable type of computation unit, e.g. a
microprocessor, digital signal processor (DSP), field programmable
gate array (FPGA), or application specific integrated circuit
(ASIC). It should be appreciated that the determination and/or the
assignment unit may be comprised as a single unit or any number of
units.
[0189] FIG. 27 illustrates an example of a user equipment 101 which
may incorporate some of the example embodiments discussed above. As
shown in FIG. 27, the user equipment 101 may comprise a receiving
401 and transmitting 404 units configured to receive and transmit,
respectively, any form of communications or control signals within
a network. It should be appreciated that the receiving 401 and
transmitting 404 units may be comprised as a single transceiving
unit. It should further be appreciated that the receiving 401 and
transmitting 404 units, or transceiving unit, may be in the form of
any input/output communications port known in the art.
[0190] The user equipment 101 may further comprise at least one
memory unit 408 that may be in communication with the receiving 401
and transmitting 404 units. The memory unit 408 may be configured
to store received or transmitted data and/or executable program
instructions. The memory unit 408 may also be configured to store
the timing compatibility hierarchy and/or HARQ control timing
configuration candidate or ordered sets. The memory unit 408 may be
any suitable type of computer readable memory and may be of
volatile and/or non-volatile type.
[0191] The user equipment 101 may further comprise an
implementation unit 408 which may be configured to implement a
control timing based on at least one timing configuration number.
The user equipment 101 may also comprise a determining unit 402
that may be configured to receive or determine the at least one
timing configuration number. The implementation unit 408 and/or the
determining unit 402 may be any suitable type of computation unit,
e.g. a microprocessor, digital signal processor (DSP), field
programmable gate array (FPGA), or application specific integrated
circuit (ASIC). It should be appreciated that the implementation
unit and the determining unit need not be provided as two separate
units but may be provided as a single or any number of units.
Example Node Operations
[0192] FIG. 28 is a flow diagram depicting example operations which
may be taken by the base station 103 of FIG. 26.
Example Operation 10
[0193] The base station determines 10 at least one timing
configuration number for a plurality of aggregated cells of the
multiple carrier network. Each aggregated cell is associated with
an uplink-downlink configuration number. At least two
uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal. The plurality of aggregated cells
is associated with the user equipment. The determination unit 308
is configured to perform the determining 10.
[0194] According to some example embodiments, the at least one
timing configuration number may be indicative of, or used to
determine, a downlink HARQ control timing configuration for
establishing downlink HARQ A/N timings across the plurality of
aggregated cells. According to some of the example embodiments, the
at least one timing configuration number may be indicative of, or
used to determine, an uplink control timing configuration number
for establishing uplink scheduling grant and/or A/N timings across
the plurality of aggregated cells.
Example Operation 11
[0195] According to some of the example embodiments, the
determining 10 may further comprise determining 11 the at least one
timing configuration number based on the uplink-downlink
configuration numbers of the plurality of aggregated cells. The
determination unit 308 is configured to perform the determining
10.
[0196] In some of the example embodiments, the at least one timing
configuration number may be determined to be equal to one of said
uplink-downlink configuration numbers of the plurality of
aggregated cells, for example as illustrated in Example Case 2
under the sub-heading Configuration Assignment. In some of the
example embodiments, the at least one timing configuration number
may be determined to not be equal to any of the uplink-downlink
configuration numbers of said plurality of aggregated cells, for
example as illustrated in Example Case 1 under the sub-heading
Configuration Assignment. The at least one timing configuration
number may be determined such that control data is transmitted to
and from the use equipment and the network in a non-conflicting
manner.
Example Operation 12
[0197] According to some of the example embodiments, the
determining 10 may further comprise determining 12 the
uplink-downlink configuration based on a subframe timing
compatibility ordering, for example as illustrated in FIG. 15. The
determination unit 308 may perform the determining 12.
Example Operation 14
[0198] According to some of the example embodiments, the
determining 12 may further comprise arranging 14 the subframe
timing compatibility ordering such that uplink-downlink
configurations on a higher level of the ordering comprise uplink
subframes that are a superset of all uplink subframes from
uplink-downlink configurations on a lower level of the ordering.
The determination unit may be configured to perform the arranging
14.
Example Operation 16
[0199] According to some of the example embodiments, the
determining 12 may further comprise arranging 16 the subframe
timing compatibility ordering such that uplink-downlink
configurations on a lower level of the ordering comprise uplink
subframes that are a superset of all downlink subframes from
uplink-downlink configurations on a higher level of the ordering.
The determination unit may be configured to perform the arranging
16.
Example Operation 18
[0200] The base station 103 assigns 18 the at least one timing
configuration number to the user equipment. The assigning unit 310
is configured to perform the assigning 18.
Example Operation 20
[0201] According to some of the example embodiments, the assigning
18 may further comprise assigning 20, in the presence of
conflicting subframes, a forward-subframe downlink scheduling with
respect to a PDCCH, as explained in FIGS. 22-25. The assigning unit
310 may be configured to perform the assigning 20.
Example Operation 22
[0202] According to some of the example embodiments, the assigning
18 may further comprise assigning 22, in the presence of
conflicting subframes, a cross a carrier forward subframe downlink
scheduling with respect to a PDCCH, as explained in FIGS. 22, 24
and 25. The assigning unit 310 may be configured to perform the
assigning 22.
Example Operation 24
[0203] According to some of the example embodiments, the method may
further comprise regulating 24 a usage of forward-subframe downlink
scheduling by monitoring, in a full-duplex mode of operation a
PDCCH in a scheduling component carrier with a downlink subframe,
if the user equipment has been given an advance grant to transmit
carrier components in an uplink direction. The assignment unit
and/or determination unit may perform the regulating 24.
Example Operation 26
[0204] According to some of the example embodiments, the method may
also comprise regulating 26 a usage of a forward-subframe downlink
scheduling by monitoring, in a half-duplex mode of operation, a
PDCCH in a scheduling component carrier with a downlink subframe,
if the user equipment has not been given an advance grant to
transmit carrier components in an uplink direction. The assignment
unit and/or determination unit may perform the regulating 26.
Example Operation 28
[0205] According to some of the example embodiments, the method may
also comprise communication 28 to the user equipment the at least
one timing configuration number via RRC signaling. The
determination unit and/or transmitting unit may perform the
communication 28.
[0206] FIG. 29 is a flow diagram depicting example operations which
may be taken by the user equipment 101 of FIG. 27.
Example Operation 30
[0207] The user equipment determines 30 at least one timing
configuration number for a plurality of aggregated cells of the
multiple carrier network, where each aggregated cell is associated
with an uplink-downlink configuration number, where at least two
uplink-downlink configuration numbers of the plurality of
aggregated cells are not equal. The plurality of aggregated cells
is associated with the user equipment. The determination 308 is
configured to perform the determining 30.
[0208] According to some example embodiments, the at least one
timing configuration number may be indicative of, or used to
determine HARQ control timing configuration for establishing
downlink HARQ A/N timings across the plurality of aggregated cells.
According to some of the example embodiments, the at least one
timing configuration number may be indicative of, or used to
determine, an uplink control timing configuration number for
establishing uplink scheduling grant and/or A/N timings across the
plurality of aggregated cells.
Example Operation 31
[0209] According to some of the example embodiments, the
determining 30 may further comprise receiving 31 the at least one
timing configuration from a base station. It should be appreciated
that the at least one timing configuration number may be received
via RRC signaling. The determining unit and/or receiving unit may
be configured to perform the receiving 31.
Example Operation 32
[0210] According to some of the example embodiments, the
determining 30 may further comprise determining 32 the at least one
timing configuration number such that control data is transmitted
to and from the user equipment and the network in a non-conflicting
manner. The determining unit may be configured to perform the
determining 32.
Example Operation 33
[0211] The user equipment 101 implements 33 control timing based on
the at least one timing configuration number. The implementation
unit 408 is configured to perform the implementing operation.
[0212] In some of the example embodiments, the at least one timing
configuration number may be implemented to be equal to one of said
uplink-downlink configuration numbers of the plurality of
aggregated cells, for example as illustrated in Example Case 2
under the sub-heading Configuration Assignment. In some of the
example embodiments, the at least one timing configuration number
may be implemented to not be equal to any of the uplink-downlink
configuration numbers of said plurality of aggregated cells, for
example as illustrated in Example Case 1 under the sub-heading
Configuration Assignment.
Example Operation 34
[0213] According to some of the example embodiments, the
implementing 33 may further comprise scheduling 34, in the presence
of conflicting subframes, a forward-subframe downlink with respect
to a PDCCH. The implementation unit 408 may be configured to
perform the scheduling 34.
Example Operation 36
[0214] According to some of the example embodiments, the
implementing 33 may further comprise scheduling 36, in the presence
of conflicting subframes, a cross component carrier
forward-subframe downlink with respect to a PDCCH. The
implementation unit 408 may be configured to perform the scheduling
36.
Example Operation 37
[0215] According to some of the example embodiments, the
implementing 33 may further comprise scheduling 37 control data,
based on the at least one timing configuration, such that the
control data is transmitted to and from the user equipment and the
network in a non-conflicting manner.
CONCLUSION
[0216] The description of the example embodiments provided herein
have been presented for purposes of illustration. The description
is not intended to be exhaustive or to limit example embodiments to
the precise form disclosed, and modifications and variations are
possible in light of the above teachings or may be acquired from
practice of various alternatives to the provided embodiments. The
examples discussed herein were chosen and described in order to
explain the principles and the nature of various example
embodiments and its practical application to enable one skilled in
the art to utilize the example embodiments in various manners and
with various modifications as are suited to the particular use
contemplated. The features of the embodiments described herein may
be combined in all possible combinations of methods, apparatus,
modules, systems, and computer program products. It should be
appreciated that the example embodiments presented herein may be
practiced in any combination with each other.
[0217] It should be noted that the word "comprising" does not
necessarily exclude the presence of other elements or steps than
those listed and the words "a" or "an" preceding an element do not
exclude the presence of a plurality of such elements. It should
further be noted that any reference signs do not limit the scope of
the claims, that the example embodiments may be implemented at
least in part by means of both hardware and software, and that
several "means", "units" or "devices" may be represented by the
same item of hardware.
[0218] A "device" as the term is used herein, is to be broadly
interpreted to include a radiotelephone having ability for
Internet/intranet access, web browser, organizer, calendar, a
camera (e.g., video and/or still image camera), a sound recorder
(e.g., a microphone), and/or global positioning system (GPS)
receiver; a personal communications system (PCS) user equipment
that may combine a cellular radiotelephone with data processing; a
personal digital assistant (PDA) that can include a radiotelephone
or wireless communication system; a laptop; a camera (e.g., video
and/or still image camera) having communication ability; and any
other computation or communication device capable of transceiving,
such as a personal computer, a home entertainment system, a
television, etc.
[0219] Although the description is mainly given for a user
equipment, as measuring or recording unit, it should be understood
by the skilled in the art that "user equipment" is a non-limiting
term which means any wireless device, terminal, or node capable of
receiving in DL and transmitting in UL (e.g. PDA, laptop, mobile,
sensor, fixed relay, mobile relay or even a radio base station,
e.g. femto base station).
[0220] A cell is associated with a radio node, where a radio node
or radio network node or eNodeB used interchangeably in the example
embodiment description, comprises in a general sense any node
transmitting radio signals used for measurements, e.g., eNodeB,
macro/micro/pico base station, home eNodeB, relay, beacon device,
or repeater. A radio node herein may comprise a radio node
operating in one or more frequencies or frequency bands. It may be
a radio node capable of CA. It may also be a single- or multi-RAT
node. A multi-RAT node may comprise a node with co-located RATs or
supporting multi-standard radio (MSR) or a mixed radio node.
[0221] The various example embodiments described herein are
described in the general context of method steps or processes,
which may be implemented in one aspect by a computer program
product, embodied in a computer-readable medium, including
computer-executable instructions, such as program code, executed by
computers in networked environments. A computer-readable medium may
include removable and non-removable storage devices including, but
not limited to, Read Only Memory (ROM), Random Access Memory (RAM),
compact discs (CDs), digital versatile discs (DVD), etc. Generally,
program modules may include routines, programs, objects,
components, data structures, etc. that perform particular tasks or
implement particular abstract data types. Computer-executable
instructions, associated data structures, and program modules
represent examples of program code for executing steps of the
methods disclosed herein. The particular sequence of such
executable instructions or associated data structures represents
examples of corresponding acts for implementing the functions
described in such steps or processes.
[0222] In the drawings and specification, there have been disclosed
exemplary embodiments. However, many variations and modifications
can be made to these embodiments. Accordingly, although specific
terms are employed, they are used in a generic and descriptive
sense only and not for purposes of limitation, the scope of the
embodiments being defined by the following claims.
* * * * *