Codebook construction
AssigneeNEC Corporation
InventorsNarayan Prasad, Guosen Yue, Mohammad Khojastepour, Sampath Rangarajan
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Abstract
A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having 1-layer, 2-layer, 3-layer, and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices, precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each of the 1-layer and 2-layer codebooks comprises a first codebook and a second codebook, and wherein each precoding matrix in the first codebook comprises a first index and a second index. Other apparatuses, systems, and methods also are disclosed.
Claims32
A method implemented in a base station used in a wireless communications system, the method comprising:
- having a first 1-layer, a second 1-layer, a first 2-layer, a second 2-layer, 3-layer and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices;
- precoding data by using one of the plurality of precoding matrices;
- and
- transmitting, to a user equipment, the precoded data,
- wherein the first 1-layer codebook includes a plurality of precoding matrices each of which comprises an element represented by
- [
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- and
- wherein the first 2-layer codebook includes a plurality of precoding matrices each of which comprises an element represented by
- [
- 1
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- -
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- -
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- each of θ2 and θ3 taking a value equal to or greater than 0 but less than 2π, and
- j=√{square root over (−1)}.
A method implemented in a user equipment used in a wireless communications system, the method comprising:
- having a first 1-layer, a second 1-layer, a first 2-layer, a second 2-layer, 3-layer and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices;
- and
- receiving, from a base station apparatus, precoded data in which data is precoded by using one of the plurality of precoding matrices,
- wherein the first 1-layer codebook includes a plurality of precoding matrices each of which comprises an element represented by
- [
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- and
- wherein the first 2-layer codebook includes a plurality of precoding matrices each of which comprise an element represented by
- [
- 1
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- -
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- -
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- each of θ2 and θ3 taking a value equal to or greater than 0 but less than 2π, and
- j=√{square root over (−1)}.
A base station used in a wireless communications system, the base station comprising:
- a transmitter to transmit, to a user equipment, precoded data,
- wherein the base station has a first 1-layer, a second 1-layer, a first 2-layer, a second 2-layer, 3-layer and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices,
- wherein the first 1-layer codebook includes a plurality of precoding matrices each of which comprises an element represented by
- [
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- and
- wherein the first 2-layer codebook includes a plurality of precoding matrices each of which comprises an element represented by
- [
- 1
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- -
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- -
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- each of θ2 and θ3 taking a value equal to or greater than 0 but less than 2π, and
- j=√{square root over (−1)}.
A user equipment used in a wireless communications system, the user equipment comprising:
- a receiver to receive, from a base station apparatus, precoded data in which data is precoded by using one of a plurality of precoding matrices,
- wherein the user equipment has a first 1-layer, a second 1-layer, a first 2-layer, a second 2-layer, 3-layer and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including the plurality of precoding matrices,
- wherein the first 1-layer codebook includes a plurality of precoding matrices each of which comprises an element represented by
- [
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- and
- wherein the first 2-layer codebook includes a plurality of precoding matrices each of which comprises an element represented by
- [
- 1
- 1
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 2
- e
- j
- ×
- θ
- 3
- -
- e
- j
- ×
- θ
- 3
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- -
- e
- j
- ×
- (
- θ
- 2
- +
- θ
- 3
- )
- ]
- ,
- each of θ2 and θ3 taking a value equal to or greater than 0 but less than 2π, and
- j=√{square root over (−1)}.
Dependencies are inferred from the claim text.