Precoded Data Receiver
AssigneeNEC Laboratories America, Inc.
InventorsMohammad A. Khojastepour, Narayan Prasad
Life of this patent
Estimating the term…
Abstract
A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.
Claims16
A method by a mobile terminal for receiving data, comprising:
- receiving data transmitted from a remote transmitter and precoded with a precoding matrix selected from a plurality of matrices that have a nested structure and are derived from a set of vector codebooks determined in accordance with the following expression:
- A
- (
- v
- i
- 1
- 1
- ,
- v
- i
- 2
- 2
- ,
- v
- i
- 3
- 3
- ,
- …
-
- )
- =
- [
- v
- i
- 1
- 1
- ,
- HH
-
- (
- v
- i
- 1
- 1
- -
- e
- 1
- M
- )
-
- [
- 0
- v
- i
- 2
- 2
- ]
- ,
- HH
-
- (
- v
- i
- 1
- 1
- -
- e
- 1
- M
- )
-
- [
- 0
- HH
-
- (
- v
- i
- 2
- 2
- -
- e
- 1
- M
- -
- 1
- )
-
- [
- 0
- v
- i
- 3
- 3
- ]
- ]
- ,
- …
- ]
- ,
- wherein e1N=[1, 0, . . . , 0]T∈CN, is the number of transmit antennas, CN is an N-dimensional complex space,
- HH
-
- (
- w
- )
- =
- {
- I
- -
- 2
-
- ww
- H
-
- w
-
- 2
- if
-
-
- w
- ≠
- 0
- I
- if
-
-
- w
- =
- 0
-
-
- and
-
-
- {
- v
- i
- j
- j
- ∈
- C
- M
- -
- j
- +
- 1
- }
- is a vector codebook and να denotes a column vector.
A mobile terminal for receiving data, comprising:
- a receiving unit to receive data transmitted from a remote transmitter and precoded with a precoding matrix selected from a plurality of matrices that have a nested structure and are derived from a set of vector codebooks determined in accordance with the following expression:
- A
- (
- v
- i
- 1
- 1
- ,
- v
- i
- 2
- 2
- ,
- v
- i
- 3
- 3
- ,
- …
-
- )
- =
- [
- v
- i
- 1
- 1
- ,
- HH
-
- (
- v
- i
- 1
- 1
- -
- e
- 1
- M
- )
-
- [
- 0
- v
- i
- 2
- 2
- ]
- ,
- HH
-
- (
- v
- i
- 1
- 1
- -
- e
- 1
- M
- )
-
- [
- 0
- HH
-
- (
- v
- i
- 2
- 2
- -
- e
- 1
- M
- -
- 1
- )
-
- [
- 0
- v
- i
- 3
- 3
- ]
- ]
- ,
- …
- ]
- ,
- wherein e1N=[1, 0, . . . , 0]T ∈CN, M is the number of transmit antennas, CN is an N-dimensional complex space,
- HH
-
- (
- w
- )
- =
- {
- I
- -
- 2
-
- ww
- H
-
- w
-
- 2
- if
-
-
- w
- ≠
- 0
- I
- if
-
-
- w
- =
- 0
-
-
- and
-
-
- {
- v
- i
- j
- j
- ∈
- C
- M
- -
- j
- +
- 1
- }
- is a vector codebook and να denotes a column vector.
A mobile terminal for receiving data, comprising:
- receiving means for receiving data transmitted from a remote transmitter and precoded with a precoding matrix selected from a plurality of matrices that have a nested structure and are derived from a set of vector codebooks determined in accordance with the following expression:
- A
- (
- v
- i
- 1
- 1
- ,
- v
- i
- 2
- 2
- ,
- v
- i
- 3
- 3
- ,
- …
-
- )
- =
- [
- v
- i
- 1
- 1
- ,
- HH
-
- (
- v
- i
- 1
- 1
- -
- e
- 1
- M
- )
-
- [
- 0
- v
- i
- 2
- 2
- ]
- ,
- HH
-
- (
- v
- i
- 1
- 1
- -
- e
- 1
- M
- )
-
- [
- 0
- HH
-
- (
- v
- i
- 2
- 2
- -
- e
- 1
- M
- -
- 1
- )
-
- [
- 0
- v
- i
- 3
- 3
- ]
- ]
- ,
- …
- ]
- ,
- wherein e1N=[1, 0, . . . , 0]T∈CN, M is the number of transmit antennas, CN is an N-dimensional complex space,
- HH
-
- (
- w
- )
- =
- {
- I
- -
- 2
-
- ww
- H
-
- w
-
- 2
- if
-
-
- w
- ≠
- 0
- I
- if
-
-
- w
- =
- 0
-
-
- and
-
-
- {
- v
- i
- j
- j
- ∈
- C
- M
- -
- j
- +
- 1
- }
-
- is a vector codebook and να denotes a column vector.
Dependencies are inferred from the claim text.