Method and system for precoding open loop spatial multiplexing and precoding indication method
The present document provides a precoding method and system for open loop spatial multiplexing and a precoding indication method. The method includes: in transmission resources, a base station precodes N-layer data to be sent by using w a = [ u a a · u a ] , wherein u a is a vector or matrix related to a transmission resource location i; α is a real number or a complex number related to the transmission resource location i; and N is an integer less than or equal to the number of base station transmission antennas.
1. A precoding method for open loop spatial multiplexing, comprising:
determining, by a base station, precoding modes of data of M+N layers to be sent, comprising:
in transmission resources, precoding, by the base station, N-layer data to be sent by using
w
a
=
[
u
a
a
·
u
a
]
,
wherein u a is a vector or matrix related to a transmission resource location i; α is a real number or a complex number related to the transmission resource location i; and N is an integer less than or equal to a number of base station transmission antennas;
in the transmission resources, precoding, by the base station, M-layer data to be sent except the N-layer data by using
w
b
=
[
u
b
β
·
u
b
]
wherein u b is a vector or matrix related to the transmission resource location i; β is a real number or a complex number related to the transmission resource location i; β=−α for same transmission resource locations, and M is an integer less than or equal to the number of base station transmission antennas.
2. The method according to claim 1 , wherein,
the u a contains N columns, the n th column is V a n , and V a n is related with the transmission resource location i.
3. The method according to claim 2 , wherein,
V a n =[1 e j2πX/32 e j4πX/32 e j6πX/32 ] T , wherein, X is an integer, and values of the X are different for different n.
4. The method according to claim 1 , wherein,
α is a scalar in a following set {1, j, −1, −j}.
5. The method according to claim 4 , wherein,
α=g(i);
g
(
i
)
=
{
1
,
mod
(
⌊
i
q
⌋
,
4
)
=
p
1
j
,
mod
(
⌊
i
q
⌋
,
4
)
=
p
2
-
1
,
mod
(
⌊
i
q
⌋
,
4
)
=
p
3
-
j
,
mod
(
⌊
i
q
⌋
,
4
)
=
p
4
;
wherein, q is an integer, values of p1, p2, p3 and p4 are one of 1, 2, 3 and 4, and are different from each other; or,
g
(
i
)
=
{
1
,
mod
(
⌊
i
q
⌋
,
2
)
=
p
1
-
1
,
mod
(
⌊
i
q
⌋
,
2
)
=
p
3
wherein, q is an integer, values of p1 and p3 are one of 1 and 2, and are different from each other.
6. The method according to claim 1 , wherein,
the u b contains M columns, the m th column is v b m , and v b m is related with the transmission resource location i.
7. The method according to claim 6 , wherein,
v b m =[1 e j2πX/32 e j4πX/32 e j6πX/32 ] T , wherein, X is an integer, and values of the X are different for different m, T represents transposing operation on a matrix.
8. The method according to claim 6 , wherein,
when the N-layer data and the M-layer data belong to a same user equipment (UE) which is served by the base station, the u a and the u b are same or different; when a sum of the M and the N is greater than 2 and the u a and the u b are different, the columns contained in the u a are a subset of the columns contained in the u b , or the columns contained in the u b are a subset of the columns contained in the u a .
9. The method according to claim 6 , wherein,
when the N-layer data and the M-layer data belong to different user equipments which are served by the base station, the u a and the u b are different.
10. The method according to claim 9 , wherein,
the u a and the u b are orthogonal.
11. The method according to claim 1 , further comprising:
notifying, by the base station, user equipments (UEs) corresponding to the data of all layers of the precoding modes corresponding to the data of all layers, the precoding modes refer to the number of precoding operations performed on the data to be sent and the number of the data layers processed in every precoding operation.
12. The method according to claim 11 , further comprising,
calculating and reporting, by the UEs, channel quality indications according to acquired precoding modes of the data of all layers.
13. A precoding system for open loop spatial multiplexing, comprising: a base station device and at least one user equipment (UE) served by the base station device, wherein,
the base station device is configured to:
in transmission resources, precode N-layer data to be sent by using
w
a
=
[
u
a
a
·
u
a
]
,
wherein, u a is a vector or matrix related to a transmission resource location i; α is a real number or a complex number related to the transmission resource location i; and N is an integer less than or equal to a number of base station transmission antennas;
in the transmission resources, precode M-layer data to be sent except the N-layer data by using
w
b
=
[
u
b
β
·
u
b
]
,
wherein u b is a vector or matrix related to the transmission resource location i; β is a real number or a complex number related to the transmission resource location i; β=−α for same transmission resource locations, and M is an integer less than or equal to the number of base station transmission antennas;
the at least one UE is configured to: use precoding modes corresponding to data of all layers determined by the base station device.
14. The system according to claim 13 , wherein,
the u a contains N columns, the n th column is V a n , and V a n is related with the transmission resource location i; and
V a n =[1 e j2πX/32 e j4πX/32 e j6πX/32 ] T , wherein, X is an integer, and values of the X are different for different n.
15. The system according to claim 13 , wherein,
α is a scalar in a following set {1, j, −1, −j}.
16. The system according to claim 13 , wherein,
the u b contains M columns, the m th column is v b m , and v b m is related with the transmission resource location i.
17. The system according to claim 16 , wherein,
when the N-layer data and the M-layer data belong to a same user equipment (UE) which is served by the base station, the u a and the u b are same or different; when a sum of the M and the N is greater than 2 and the u a and the u b are different, the columns contained in the u a are a subset of the columns contained in the u b , or the columns contained in the u b are a subset of the columns contained in the u a ; and
when the N-layer data and the M-layer data belong to different user equipments, the u a and the u b are orthogonal.