Reporting of channel state information
A mobile station connected to a multi-carrier cellular communication system having a plurality of sub-carriers. The sub-carriers are classified into K frequency sub-bands, channel state information (CSI) of the frequency sub-bands is represented by matrices W i (i=0 . . . K−1), where K is an integer greater than 1. The mobile station determines a first sub-index k 1 for the K matrices W 1 (i =0...K -1), and a second sub-index k2 for each one of the K matrices W i (i=0 . . . K−1). The first sub-index k 1 is common for all frequency sub-bands, and the second sub-index k 2 is specific for the indexed matrix that corresponds to one frequency sub-band. The mobile station reports to a base station of the multi-carrier cellular communication system the first sub-index k 1 and at least one second sub-index k 2 .
1. An apparatus, comprising:
a non-transitory storage medium including comprising executable instructions; and
a processor configured to execute the executable instructions to communicate with a base station in a multi-carrier cellular communication system communicating through a plurality of sub-carriers, wherein the plurality of sub-carriers are divided into a plurality of subbands, and the instructions which, when executed by the processor, cause the apparatus to:
determine a first sub-index and a second sub-index, wherein the first sub-index belongs to a plurality of first sub-indices and the second sub-index belongs to a plurality of second sub-indices, and the first sub-index and the second sub-index form a precoding matrix indicator (PMI) of a matrix for the plurality of subbands, and
report the first sub-index and the second sub-index on a physical uplink control channel (PUCCH), wherein the first sub-index and the second sub-index are both wideband feedback and are common for the plurality of subbands, and the plurality of first sub-indices and the plurality of second sub-indices have a dependency relationship.
2. The apparatus according to claim 1 , wherein the matrix comprises a first sub-matrix and a second sub-matrix,
the first sub-index indicates the first sub-matrix from a first sub-codebook; and
the second sub-index indicates the second sub-matrix from a second sub-codebook.
3. The apparatus according to claim 2 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
1
M
k
2
i
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
4. The apparatus according to claim 2 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
2
i
M
k
1
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
5. The apparatus according to claim 2 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W i =M k 2 i M k 1 or W i =M k 1 M k 2 i ,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
6. The apparatus according to claim 2 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
1
e
i
d
k
2
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and d k 2 represents the second sub-matrix, wherein the second sub-matrix is scalar.
7. The apparatus according to claim 1 , wherein the multi-carrier cellular communication system is selected from at least one of a long term evolution (LTE) system or a long term evolution advanced (LTE-A) system.
8. A method of communication
in a multi-carrier cellular communication system having a plurality of sub-carriers, wherein the plurality of sub-carriers are divided into a plurality of subbands, comprising:
determining, by a terminal device, a first sub-index and a second sub-index, wherein the first sub-index belongs to a plurality of first sub-indices and the second sub-index belongs to a plurality of the second sub-indices, the first sub-index and the second sub-index form a precoding matrix indicator (PMI) of a matrix for the plurality of subbands; and
reporting, by the terminal device, the first sub-index and the second sub-index on a physical uplink control channel (PUCCH),
wherein the first sub-index and the second sub-index are both wideband feedback and common for the plurality of subbands, and the plurality of first sub-indices and the plurality of second sub-indices have a dependency relationship.
9. The method according to claim 8 , wherein the matrix comprises a first sub- matrix and a second sub-matrix,
the first sub-index indicates the first sub-matrix from a first sub-codebook; and
the second sub-index indicates the second sub-matrix from a second sub-codebook.
10. The method according to claim 9 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
1
M
k
2
i
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
11. The method according to claim 9 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
2
i
M
k
1
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k i represents the first sub-matrix, and Mk k 2 i represents the second sub-matrix.
12. The method according to claim 9 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W i =M k 2 i M k 1 or W i =M k 1 M k 2 i ,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
13. The method according to claim 9 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
1
e
j
d
k
2
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and d k 2 represents the second sub-matrixm wherein the second sub-matrix is scalar.
14. The method according to claim 8 , wherein the multi-carrier cellular communication system is a long term evolution (LTE) system or a long term evolution advanced (LTE-A) system.
15. A non-transitory computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to:
determine a first sub-index and a second sub-index, wherein the first sub-index belongs to a plurality of first sub-indices and the second sub-index belongs to a plurality of second sub-indices, and the first sub-index and the second sub-index form a precoding matrix indicator (PMI) of a matrix for a plurality of subbands; and
report the first sub-index and the second sub-index on a physical uplink control channel (PUCCH),
wherein the first sub-index and the second sub-index are both wideband feedback and are common for the plurality of subbands, and the plurality of first sub-indices and the plurality of second sub-indices have a dependency relationship.
16. The non-transitory computer-readable storage medium according to claim 15 , wherein the matrix comprises a first sub-matrix and a second sub-matrix,
the first sub-index indicates the first sub-matrix from a first sub-codebook; and
the second sub-index indicates the second sub-matrix from a second sub-codebook.
17. The non-transitory computer-readable storage medium according to claim 16 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
1
M
k
2
i
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
18. The non-transitory computer-readable storage medium according to claim 16 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
2
i
M
k
1
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
19. The non-transitory computer-readable storage medium according to claim 16 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W i =M k 2 i M k 1 or W i =M k 1 M k 2 i ,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and M k 2 i represents the second sub-matrix.
20. The non-transitory computer-readable storage medium according to claim 16 , wherein
the matrix is represented as W i , where 0≤i≤K−1; and
W i , the first sub-matrix, and the second sub-matrix are related as:
W
i
=
[
M
k
1
M
k
1
e
j
d
k
2
]
,
where W i represents the i th matrix, k 1 represents the first sub-index, k 2 represents the second sub-index, M k 1 represents the first sub-matrix, and d k 2 represents the second sub-matrix, wherein the second sub-matrix is scalar.