U.S. patent application number 14/706348 was filed with the patent office on 2015-10-01 for channel state informaion measurement and reporting.
The applicant listed for this patent is Cellular Communications Equipment LLC. Invention is credited to Timo Erkki Lunttila, Klaus Ingemann Pedersen.
Application Number | 20150281994 14/706348 |
Document ID | / |
Family ID | 44741330 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150281994 |
Kind Code |
A1 |
Pedersen; Klaus Ingemann ;
et al. |
October 1, 2015 |
CHANNEL STATE INFORMAION MEASUREMENT AND REPORTING
Abstract
A rule specifies a timing relation between a measurement
configuration which indicates at least one subframe to measure and
a reporting configuration which indicates at least one subframe in
which to report. This rule is used by both user equipment UE and
network to map between a downlink subframe in which channel state
information is measured and an uplink subframe in which the channel
state information is reported. The network may configure the UE
with the measurement and reporting configurations via dedicated
signaling or broadcast. If the measurement configuration is
periodic and indicates multiple downlink subframes to measure the
rule results in a one to one mapping of downlink to uplink subframe
where less than all of the multiple downlink subframes map to an
uplink subframe; if aperiodic the rule indicates a single downlink
subframe to measure.
Inventors: |
Pedersen; Klaus Ingemann;
(Aalborg, DK) ; Lunttila; Timo Erkki; (Espoo,
FI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cellular Communications Equipment LLC |
Plano |
TX |
US |
|
|
Family ID: |
44741330 |
Appl. No.: |
14/706348 |
Filed: |
May 7, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13253323 |
Oct 5, 2011 |
9100868 |
|
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14706348 |
|
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|
61389865 |
Oct 5, 2010 |
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Current U.S.
Class: |
370/252 |
Current CPC
Class: |
H04W 72/042 20130101;
Y02D 30/70 20200801; Y02D 70/1262 20180101; H04W 72/082 20130101;
H04W 72/0413 20130101; H04W 24/10 20130101; H04B 7/0626 20130101;
Y02D 70/1242 20180101; Y02D 70/1264 20180101; H04W 36/0088
20130101 |
International
Class: |
H04W 24/10 20060101
H04W024/10; H04B 7/06 20060101 H04B007/06 |
Claims
1. A method comprising: storing in a local memory a rule that
specifies a timing relation between a measurement configuration
which indicates at least one subframe to measure and a reporting
configuration which indicates at least one subframe in which to
report; and using the rule to map between a downlink subframe in
which channel state information is measured and an uplink subframe
in which the channel state information is reported.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This patent application is a continuation of U.S.
application Ser. No. 13/253,323 filed Oct. 5, 2011 and claims
priority under 35 U.S.C. 119(e) from Provisional Patent Application
No. 61/389,865, filed Oct. 5, 2010, the disclosure of which are
incorporated by reference herein in their entirety.
TECHNICAL FIELD
[0002] The exemplary and non-limiting embodiments of this invention
relate generally to wireless communication systems, methods,
devices and computer programs and, more specifically, relate to
channel quality/channel state measurement and reporting.
BACKGROUND
[0003] The following abbreviations are herewith defined:
[0004] 3GPP third generation partnership project
[0005] CSG closed subscriber group
[0006] CSI channel state Information
[0007] DL downlink
[0008] eNB evolved nodeB (of an LTE system)
[0009] eICIC enhanced inter-cell interference coordination
[0010] E-UTRAN evolved UTRAN (LTE or 3.9G)
[0011] HARQ hybrid automatic repeat request
[0012] HeNB home eNB (base station)
[0013] LTE long term evolution of 3GPP
[0014] LTE-A long term evolution-Advanced
[0015] Node B base station or similar network access node
[0016] PDCCH physical downlink control channel
[0017] RRC radio resource control
[0018] TDM time-domain multiplexing (or time division multiple
access)
[0019] UE user equipment (e.g., mobile equipment/station)
[0020] UL uplink
[0021] UMTS universal mobile telecommunications system
[0022] UTRAN UMTS terrestrial radio access network
[0023] As the radio spectrum becomes more thoroughly utilized,
geographic overlap among different radio networks becomes more
prevalent. By example, in the LTE system (and LTE-A) there is the
conventional or macro cell whose coverage area overlaps in whole or
in part with that of a home network which serves a closed
subscriber group CSG. One example of such overlap is shown at FIG.
1: the macro base station is the eNB 12 and the home base station
is the HeNB 13. Three mobile devices are shown, in which UE 10-1
and 10-3 are under control of the eNB 12 and UE 10-2 is under
control of the HeNB 13. Whereas the dashed line coverage area of
the HeNB 13 is shown as being fully enveloped within the coverage
area of the eNB 12 (the entirety of FIG. 1), it will be recognized
that some deployments may exhibit only a partial overlap. As used
further herein, the term eNB refers to the macro access node and
the home access node will be specified as such to distinguish the
two.
[0024] In the particular arrangement of HeNBs in the LTE system as
well as similarly overlapping cells in other radio technologies,
radio channels may be shared which gives rise to co-channel
interference among the various UL and DL signals from the different
but closely located radios. In LTE and LTE-A there is time-domain
(TDM) enhanced inter-cell interference coordination (eICIC) which
is applied between the eNBs and the HeNBs to reduce the co-channel
interference between cells. For such cases it is also beneficial to
optimize the channel state information (CSI) which the various UEs
report on the UL to their respective access nodes, which enables
the aforementioned TDM eICIC to also be optimized.
[0025] The TDM eICIC concept for LTE (and LTE-A) rests on the
proposition that the HeNB 13 is only allowed to transmit in a
sub-set of all DL subframes FIG. 2 is a table of DL subframes for
the eNB and the HeNB which gives an example of the principle. The
eNB is not restricted in which DL subframes it may transmit which
is indicated by all DL subframes being shaded in FIG. 2 at the
macro layer. The HeNB is restricted and is allowed to transmit only
in the subset of DL subframes shaded in FIG. 2 for the HeNB layer,
specifically subframes 1 through 4. At FIG. 2 subframes 5 through 8
are unshaded for the HeNB layer meaning they are almost blank. In
this context, "almost blank" refers to cases with nearly no
transmission from the HeNB and its transmissions are highly
restricted (e.g., multi-media broadcast over a single frequency
MBSFN is allowed in those DL subframes). In concept, the macro-UEs
(under control of the eNB, perhaps those not allowed to connect CSG
HeNB) which are close to the HeNB shall be scheduled during the
time-periods with almost blank sub-frames from the HeNBs. By
example, this means the eNB 12 should schedule UE 10-1 in any of
subframes 5 through 8, which avoids that UE's DL signal from being
exposed to too high interference. Other macro-UEs such as UE 10-3
could also be scheduled by the eNB 12 in other sub-frames.
[0026] For the TDM eICIC to operate properly, it is in generally
assumed that the eNBs know in which sub-frames the HeNBs are muted.
There has also been proposals in 3GPP discussions that the eNB
signal to its own UEs which sub-frames are almost blanked (and
therefore in possible use by the HeNBs).
[0027] The eICIC concept gives rise to several unresolved problems.
First, for macro-UEs which are operating close to a non-allowed CSG
HeNB such as UE 10-1 of FIG. 1, the CSI this UE reports on the UL
to its eNB 12 will be significantly different depending on whether
the reported CSI is measured during time-periods with almost blank
sub-frames from HeNBs, or in other sub-frames. Second, in general
the eNB 12 does not know the exact location of the UEs under its
control, and so to adopt the scheduling for UE 10-1 noted by
example above the eNB 12 must estimate its geographic location in
order to determine whether or not it is close to some CSG HeNB 13
which it is not allowed to join.
[0028] There have been a few proposals to the 3GPP concerning CSI
for TDM eICIC. Document R1-102353 entitled "Measurements and
feedback extensions for improved operations in HetNets", by
Qualcomm (3GPP TSG-RAN WG1 #60 bis; 12-16 Apr. 2010; Beijing,
China) proposes that the UE performs measurement on a set of
subframes which the network signals, and that channel feedback is
restricted to a single subframe. Limiting the feedback measurements
to some specific subframes (e.g. either normal or almost blank) is
intended to provide better feedback accuracy corresponding more
directly to the TDM eICIC scheme in use. This appears to follow the
CSI regimen for LTE Rel-8/9 which is specified in 3GPP TS36.213
v9.2.0 (2010-06). Specifically, the CSI reference resource is
always a single subframe and the CSI is reported in an UL subframe
spaced a fixed distance from the subframe which was measured,
following the general HARQ timing (i.e. CSI measured in subframe n
is transmitted in the UL subframe n+4).
[0029] Document R1-101981 entitled "Enhanced ICIC and
Resource-Specific CQI Measurement", by Huawei (3GPP TSG-RAN WG1 #60
bis; 12-16 Apr. 2010; Beijing, China) discusses a
time/resource-specific CSI measurement, which limits the CQI
averaging to some specific subframes depending on the network
deployment model (e.g. HetNet). In practice this averaging appears
quite problematic for the UE as it increases battery consumption
and complicates memory handling since the measurements need to be
buffered for multiple subframes.
SUMMARY
[0030] In a first exemplary aspect of the invention there is a
method comprising: storing in a local memory a rule that specifies
a timing relation between a measurement configuration which
indicates at least one subframe to measure and a reporting
configuration which indicates at least one subframe in which to
report; and using the rule to map between a downlink subframe in
which channel state information is measured and an uplink subframe
in which the channel state information is reported.
[0031] In a second exemplary aspect of the invention there is an
apparatus comprising at least one processor and at least one
memory. The at least one memory includes computer program code and
a rule that specifies a timing relation between a measurement
configuration which indicates at least one subframe to measure and
a reporting configuration which indicates at least one subframe in
which to report. The at least one memory and the computer program
code are configured with the at least one processor to cause the
apparatus at least to perform: using the rule to map between a
downlink subframe in which channel state information is measured
and an uplink subframe in which the channel state information is
reported.
[0032] In a third exemplary aspect of the invention there is a
computer readable memory storing a rule that specifies a timing
relation between a measurement configuration which indicates at
least one subframe to measure and a reporting configuration which
indicates at least one subframe in which to report. The computer
readable memory also stores a program of computer readable
instructions that when executed by a processor result in actions
comprising: using the rule to map between a downlink subframe in
which channel state information is measured and an uplink subframe
in which the channel state information is reported.
[0033] In a fourth exemplary aspect of the invention there is an
apparatus comprising storing means and processing means. The
storing means is for storing a rule that specifies a timing
relation between a measurement configuration which indicates at
least one subframe to measure and a reporting configuration which
indicates at least one subframe in which to report. The processing
means is for using the rule to map between a downlink subframe in
which channel state information is measured and an uplink subframe
in which the channel state information is reported.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The foregoing and other aspects of the exemplary embodiments
of this invention are made more evident in the following Detailed
Description, when read in conjunction with the attached Drawing
Figures.
[0035] FIG. 1 is a schematic diagram showing a macro eNB cell and a
CSG home eNB cell which are subject to co-channel interference and
which is an environment in which exemplary embodiments of the
invention may be advantageously practiced.
[0036] FIG. 2 is a timing diagram of downlink subframes for a macro
eNB and a CSG Home eNB and illustrating an inter-cell interference
mitigation scheme relevant to certain exemplary embodiments of the
invention.
[0037] FIG. 3A is a timing diagram showing CSI related subframes
set forth in LTE Release 8.
[0038] FIG. 3B is a timing diagram showing DL subframes in which
CSI is measured and UL subframes in which the measured CSI is
reported according to an exemplary embodiment of the invention.
[0039] FIG. 4 is a simplified block diagram of various electronic
devices that are suitable for use in practicing the exemplary
embodiments of this invention.
[0040] FIG. 5 is a logical flow diagram that illustrates the
operation of a method, and result of execution of computer program
instructions embodied on a computer readable memory, in accordance
with the exemplary embodiments of this invention.
DETAILED DESCRIPTION
[0041] Though not limited thereto, embodiments of this invention
are particularly advantageous for use in an LTE and LTE-A systems,
and concern mapping between subframes in which the UE measures CSI
and subframes in which the UE sends measured CSI to the eNB. In
LTE/LTE-A and also in certain other radio technologies it is the
network which directs the UE which subframes to measure, and there
is a mapping between the subframe being measured and the subframe
in which the measurements are reported. Both the UE and the network
use the same mapping though perhaps in reverse order, and therefore
embodiments of these teachings apply to both the UE and to the eNB.
While the concept is described with reference to LTE and/or LTE-A,
such description is by example only and not a limitation; these
teachings may be readily extended to other communication systems
other than E-UTRAN.
[0042] Particularly for the exemplary environment shown at FIG. 1,
often the network would prefer to distinguish the CSI reported to
it between the almost blank subframes and the other subframes which
are not almost blank. For optimal scheduling and link adaptation it
would be beneficial for the network to control in which sub-frames
CSI is measured. Since in different situations the network might
want CSI for either the almost blanked subframes or for the other
subframes, exemplary embodiments of the invention are flexible
enough to enable the eNB to schedule CSI to be measured for
either.
[0043] In exemplary embodiments of the invention the network
signals to the UE a CSI reporting configuration, which may be for
periodic CSI reporting or for aperiodic CSI reporting. The CSI
reporting configuration tells the UE in which UL subframe(s) to
report its CSI measurement(s).
[0044] In addition to this the network also signals the UE with a
"CSI measurement subframe configuration" which indicates the
subframes in which the UE should measure CSI. This configuration
could also be periodic or aperiodic, and by example it may be
signaled via dedicated RRC signaling or via non-dedicated
broadcast. By example the periodic CSI measurement subframe
configuration may include parameters such as periodicity and
subframe offset. By example the aperiodic CSI measurement subframe
configuration may be a bitmap indicating in which subframes the UE
should measure CSI. Similarly the periodic CSI measurement subframe
configuration may be signaled as a bitmap indicting which
subframe(s) of a radio frame the UE is to measure CSI, and also
including an indication that the configuration is periodic. In an
embodiment the eNB has the flexibility to configure a particular UE
with multiple CSI measurement subframe configurations
simultaneously.
[0045] In addition to the CSI reporting configuration and the CSI
measurement subframe configuration, there is also rule that ties a
given CSI measurement subframe configuration to a specific CSI
reporting configuration by giving an unambiguous timing relation
between their DL and UL subframes. In a specific embodiment such a
rule is summarized below: [0046] The UE shall perform the CSI
measurements in the subframes indicated by the CSI measurement
subframe configuration. [0047] In the subframes indicated by CSI
reporting configuration the UE shall report the CSI measured in the
most recent subframe (that with the largest subframe index)
indicated by the CSI measurement subframe configuration satisfying
the condition:
[0047] N.sub.CSI-meas.ltoreq.N.sub.CSI-report-t.sub.proc;
where [0048] N.sub.CSI-meas is the index of the CSI measurement
subframe. [0049] N.sub.CSI-report is the index of the CSI reporting
subframe. [0050] t.sub.proc is the minimum processing time allowed
for the UE to process the measurement.
[0051] The timing diagram of FIG. 3A illustrates CSI related timing
for LTE Release 8. The CSI reference resource is the DL subframe
which the UE measures, and the UE sends that measured CSI in the UL
subframe spaced always four subframes after the DL CSI reference
resource. Specifically, assume the eNB tasks the UE to measure CSI
in each 10.sup.th subframe beginning at subframe index #3. At FIG.
3A the UE reports in UL subframe index 7 the CSI it measured at DL
subframe index #3; reports in UL subframe index 17 the CSI it
measured at DL subframe index #13; and so forth. There is no
specific signaling by the eNB of which UL subframe the UE is to
report because the wireless standard stipulates the mapping is
always UL=DL+4, and both UE and eNB know that fixed mapping.
Spacing of four subframes is used to allow the UE sufficient time
to process the measured DL results and compile them into the
message to be sent on the UL.
[0052] The timing diagram of FIG. 3B illustrates CSI related timing
according to an exemplary embodiment of the invention for periodic
CSI reporting. For FIG. 3B assume that the eNB configures the UE
with a CSI measurement subframe configuration having parameters
periodicity=3 and an offset such that the UE sets its first DL
subframe to measure CSI as index #0 of FIG. 3B. This CSI
measurement subframe configuration designates subframe indices 0,
3, 6, 9, 12, etc. as CSI measurement subframes for the UE as shown
by shading in the row CS/measurement subframe configuration at FIG.
3B. Assume further for FIG. 3B that the eNB configures the UE with
a CSI reporting configuration having parameters periodicity=10 and
an offset such that the UE sets its first UL subframe to report CSI
as index #7 of FIG. 3B. If we further assume the processing delay
t.sub.proc of the above rule is 3 or 4 subframes, then the
designated UL subframes for CSI reporting are subframe indices 7,
17, 27, etc. for the UE as shown by shading in the row CS/reporting
configuration at FIG. 3B.
[0053] By the exemplary rule set forth above, the UE reports in the
designated UL subframes only the CSI that it measures in the
subframes that are shaded in the row CSI measurement of FIG. 3B.
Specifically, the UE reports in UL subframe index 7 the CSI it
measured at DL subframe index #3; reports in UL subframe index 17
the CSI it measured at DL subframe index #12; and reports in UL
subframe index 27 the CSI it measured at DL subframe index #21.
Designated CSI measurement subframes 0, 6, 9, 15, 18 and 24 do not
meet the criteria set forth at the example rule above, and since
the UE knows the rule and the UL reporting subframes in advance in
one exemplary embodiment the UE need not even measure CSI in those
subframes. In another exemplary embodiment the wireless standard
which mandates UE behavior according to these teachings may require
the UE to measure CSI in those subframes anyway (e.g., the UE is
directed to measure CSI in all subframes designated by the CSI
measurement subframe configuration). This is in case the eNB sends
a new (aperiodic) CSI reporting configuration which would trigger a
report of the CSI from one of those other subframes.
[0054] Using the CSI measurement subframe configuration and the
periodic CS/reporting configuration the eNB could task the UE to
measure and report only almost blank subframes, or the other
subframes, or some combination of them in separate reporting
instances as the eNB/network sees fit for its needs.
[0055] The aperiodic reporting embodiments follow similar to the
above described periodic reporting example, except there is no
repeated measuring and reporting from the signaled configurations.
As noted above with the periodic reporting example the UE may
perform CSI measurements in advance of the aperiodic CSI reporting
configuration, just in case the eNB does send an aperiodic CSI
report request.
[0056] In an exemplary aperiodic embodiment the definition of the
LTE Release 8/9 aperiodic CSI reporting can be extended so that the
network can request CSI that is measured either during time-periods
where HeNBs are almost muted, or during other sub-frames. This
implies that when the eNB requests an aperiodic (scheduled) CSI,
the request which in this case is sent via the PDCCH grant of UL
resources should include information on which CSI measurement
subframe configuration the report should correspond to.
[0057] In exemplary embodiments both the UE and the macro eNB
implement aspects of the invention for they both store in their
local memories the rule and the measurement and reporting
configurations which are valid for that specific UE at a given
time. Specific implementations have the rule mapping one DL
measurement subframe to one and only one UL reporting subframe, as
in the above example. Those DL measurement subframes which do not
map are not in these exemplary embodiments used to average a result
which is then reported because in these specific embodiments the
macro eNB 12 disaggregates CSI measured on the almost blank
subframes from CSI measured on the other subframes by having CSI of
only one DL subframe reported in only one UL subframe. Other
implementations may use an averaging in select instances, different
from the specific examples above.
[0058] On technical effect is that the exemplary embodiments
detailed above enable the network to take full advantage of TDM
eICIC by facilitating appropriate scheduling of macro-UEs according
to a more precise view of their respective DL channel quality.
Another technical effect of having the CSI resource specific
sub-frame configuration as in these exemplary embodiments is that
the macro eNB is enabled to more accurately estimate whether a
macro UE shall be restricted to being scheduled only during
sub-frames with HeNB muting, or whether it is also feasible to
schedule it in other sub-frames. This technical effect is present
even without the macro eNB knowing the geographic location of that
macro UE.
[0059] Reference is now made to FIG. 4 for illustrating a
simplified block diagram of various electronic devices that are
suitable for use in practicing the exemplary embodiments of this
invention. In FIG. 4 a wireless network 1 is adapted for
communication with a UE 10 via a node B (e.g., base station or
macro-eNB) 12. The network 1 may include a higher controlling node
generically shown as a gateway GW 14, which may be referred to
variously as a radio network controller RNC, a mobility management
entity MME, or a system architecture evolution gateway SAE-GW. The
GW 14 represents a node higher in the network than the eNB 12 and
in certain embodiments the signaling detailed herein is independent
of that GW 14, except to the extent the eNB 12 may sometimes pass
certain CSI information it receives from the UE 10 to the GW
14.
[0060] The UE 10 includes a data processor (DP) 10A, a memory (MEM)
10B that stores a program (PROG) 10C, and a suitable radio
frequency (RF) transmitter and receiver 10D for bidirectional
wireless communications with the eNB 12, which also includes a DP
12A, a MEM 12B that stores a PROG 12C, and a suitable RF
transmitter and receiver 12D. The eNB 12 may be coupled via a data
path 13 (e.g., lub or S1) to the serving or other GW 14. The eNB 12
and the UE 10 communicate over a wireless link 11, each using one
or more antennas (one antenna shown for each). In an embodiment,
the wireless link 11 is a physical downlink control channel such as
PDCCH and the uplink is a physical uplink shared channel such as
the PUSCH. At least one of the PROGs 10C and 12C is assumed to
include program instructions that, when executed by the associated
DP, enable the electronic device to operate in accordance with the
exemplary embodiments of this invention, as discussed below in
greater detail.
[0061] Within the UE 10, either separate from or within the DP 10A,
is a subframe mapper 10E that uses the rule and the configurations
stored in the MEM 10B to map between the DL subframe which the UE
measures CSI to the UL subframe in which the UE reports the
measured CSI. Also within the eNB 12, either separate from or
within the DP 12A, is a subframe mapper 12E that uses the rule and
the configurations stored in the MEM 12B to map between the
measuring DL and reporting UL subframes mentioned above. Further,
within each device 10, 12, 14 is a modem; for the UE 10 and eNB 12
such a modem is embodied within the respective transmitter/receiver
10D, 12D, and is embodied within the DP 12A, 14A of the respective
eNB 12 and GW 14 for communicating over the data link 13 between
them.
[0062] The terms "connected," "coupled," or any variant thereof,
mean any connection or coupling, either direct or indirect, between
two or more elements, and may encompass the presence of one or more
intermediate elements between two elements that are "connected" or
"coupled" together. The coupling or connection between the elements
can be physical, logical, or a combination thereof. As employed
herein two elements may be considered to be "connected" or
"coupled" together by the use of one or more wires, cables and
printed electrical connections, as well as by the use of
electromagnetic energy, such as electromagnetic energy having
wavelengths in the radio frequency region, the microwave region and
the optical (both visible and invisible) region, as non-limiting
examples.
[0063] At least one of the PROGs 10C, 12C and 14C is assumed to
include program instructions that, when executed by the associated
DP, enable the electronic device to operate in accordance with the
exemplary embodiments of this invention. Inherent in the DPs 10A,
12A is a clock to enable synchronism among the various devices for
transmissions and receptions within the appropriate time intervals
and slots required.
[0064] In general, the exemplary embodiments of this invention may
be implemented by computer software PROGs 10C, 12C, 14C embodied on
the respective memories MEMs 10B, 12B, 14C and executable by the
respective DPs 10A, 12A, 14A of the UE 10, eNB 12 and GW 14, or by
hardware, or by a combination of software and/or firmware and
hardware.
[0065] In general, the various embodiments of the UE 10 can
include, but are not limited to, cellular telephones, personal
digital assistants (PDAs) having wireless communication
capabilities, portable computers having wireless communication
capabilities, image capture devices such as digital cameras having
wireless communication capabilities, gaming devices having wireless
communication capabilities, music storage and playback appliances
having wireless communication capabilities, Internet appliances
permitting wireless Internet access and browsing, as well as
portable units or terminals that incorporate combinations of such
functions.
[0066] The MEMs 10B and 12B may be of any type suitable to the
local technical environment and may be implemented using any
suitable data storage technology, such as semiconductor-based
memory devices, magnetic memory devices and systems, optical memory
devices and systems, fixed memory and removable memory. The DPs 10A
and 12A may be of any type suitable to the local technical
environment, and may include one or more of general purpose
computers, special purpose computers, microprocessors, digital
signal processors (DSPs) and processors based on a multi-core
processor architecture, as non-limiting examples.
[0067] For the aspects of this invention related to the
network/eNB, embodiments of this invention may be implemented by
computer software executable by a data processor of the Node B 12,
such as the processor 12A shown, or by hardware, or by a
combination of software and hardware. For the aspects of this
invention related to the UE, embodiments of this invention may be
implemented by computer software executable by a data processor of
the UE 10, such as the processor 10A shown, or by hardware, or by a
combination of software and hardware. Further in this regard it
should be noted that the various logical step descriptions above
and at FIG. 5 below may represent program steps, or interconnected
logic circuits, blocks and functions, or a combination of program
steps and logic circuits, blocks and functions.
[0068] Further details and implementations are described
particularly below with reference to FIG. 5. Exemplary embodiments
of this invention encompass a method; an apparatus that includes a
processor, memory, transmitter and receiver; and a memory embodying
a computer program; that at block 502 stores in a local memory a
rule that specifies a timing relation between a measurement
configuration which indicates at least one subframe to measure and
a reporting configuration which indicates at least one subframe in
which to report; and at block 504 uses the rule to map between a
downlink subframe in which channel state information is measured
and an uplink subframe in which the channel state information is
reported.
[0069] Optional blocks are shown by dashed lines at FIG. 5. At
block 506 is shown that the measurement configuration and the
reporting configuration are configured for a user equipment using
wireless signaling. At block 508 are shown the two different
options of at least the measurement configuration being configured
for the user equipment via dedicated wireless signaling or via
broadcast signaling.
[0070] Block 510 is from the specific example above; the
measurement configuration is periodic and indicates multiple
downlink subframes to measure and using the rule to map between the
downlink subframe and the uplink subframe results in a one to one
mapping of one downlink subframe to one uplink subframe in which
less than all of the multiple downlink subframes map to an uplink
subframe. The alternative to block 510 is at block 512, in which at
least the measurement configuration is aperiodic and indicates a
single downlink subframe to measure. For either periodic or
aperiodic, block 514 shows the particular embodiment in which the
measurement configuration of block 502 is signaled to the UE as a
bitmap indicating which subframe(s) of a plurality of subframes to
measure. By example the bitmap may indicate which subframe(s) of a
radio frame are to be measured. In LTE there are ten subframes in
one radio frame.
[0071] Note that blocks 502 and 504 may be executed by a network
access node macro-eNB, which sends to the UE the measurement
configuration and the reporting configuration, and uses the rule at
block 504 by mapping between an uplink subframe in which the
channel state information is received from the user equipment and a
downlink subframe indicated by the measurement configuration. In
another embodiment blocks 502 and 504 are executed by the user
equipment which receives from a network the measurement
configuration and the reporting configuration, and which uses the
rule of block 504by mapping between a downlink subframe indicated
by the measurement configuration in which the user equipment
measures channel state information and an uplink subframe in which
the user equipment reports the measured channel state information
to the network.
[0072] An embodiment of the invention may be an apparatus
comprising at least one processor, and at least one memory
including computer program code and a rule that specifies a timing
relation between a measurement configuration which indicates at
least one subframe to measure and a reporting configuration which
indicates at least one subframe in which to report. In such an
embodiment the at least one memory and the computer program code
configured, with the at least one processor, to cause the apparatus
at least to perform using the rule to map between a downlink
subframe in which channel state information is measured and an
uplink subframe in which the channel state information is reported.
Such an apparatus may also be configured to perform the optional
steps at block 5.
[0073] Another embodiment is an apparatus comprising storing means
for storing a rule that specifies a timing relation between a
measurement configuration which indicates at least one subframe to
measure and a reporting configuration which indicates at least one
subframe in which to report; and processing means for using the
rule to map between a downlink subframe in which channel state
information is measured and an uplink subframe in which the channel
state information is reported. Such an apparatus may also be
configured to perform the optional steps at block 5.
[0074] In general, the various exemplary embodiments may be
implemented in hardware or special purpose circuits, software,
logic or any combination thereof. As such, it should be appreciated
that at least some aspects of the exemplary embodiments of the
inventions may be practiced in various components such as
integrated circuit chips and modules.
[0075] Various modifications and adaptations may become apparent to
those skilled in the relevant arts in view of the foregoing
description, when read in conjunction with the accompanying
drawings and the appended claims. For example, certain steps shown
in FIG. 3 may be executed in other than the order shown, and
certain of the computations described may be performed in other
ways. However, all such and similar modifications of the teachings
of this invention will still fall within the scope of this
invention.
[0076] It should be noted that the terms "connected," "coupled," or
any variant thereof, mean any connection or coupling, either direct
or indirect, between two or more elements, and may encompass the
presence of one or more intermediate elements between two elements
that are "connected" or "coupled" together. The coupling or
connection between the elements can be physical, logical, or a
combination thereof. As employed herein two elements may be
considered to be "connected" or "coupled" together by the use of
one or more wires, cables and/or printed electrical connections, as
well as by the use of electromagnetic energy, such as
electromagnetic energy having wavelengths in the radio frequency
region, the microwave region and the optical (both visible and
invisible) region, as several non-limiting and non-exhaustive
examples.
[0077] Furthermore, some of the features of the examples of this
invention may be used to advantage without the corresponding use of
other features. As such, the foregoing description should be
considered as merely illustrative of the principles, teachings,
examples and exemplary embodiments of this invention, and not in
limitation thereof.
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