Transmission of an information sequence
View Patent ↗A method implemented in a mobile communications system for data transmission is disclosed. The method includes selecting a set of parallel channels, determining transmission rank, and determining a precoding matrix of the transmission rank for the set of parallel channels, wherein the precoding matrix is formed by applying householder transformation to a vector to make a matrix and selecting one or more columns from the matrix. Other methods and apparatuses also are disclosed.
1. A method implemented in a mobile communications system for data transmission, the method comprising:
selecting a set of parallel channels;
determining transmission rank; and
determining a precoding matrix of the transmission rank for the set of parallel channels,
wherein the precoding matrix is formed by applying householder transformation to a vector to make a matrix and selecting one or more columns from the matrix, and
wherein the householder transformation is defined by the following formula:
HH
(
x
)
=
I
-
2
xx
*
x
2
,
where x is the vector, I is an identity matrix, x* is Hermitian conjugate of x, and ∥x∥ is norm of x.
2. The method as in claim 1 , further comprising:
feeding back an indication of the precoding matrix to a base station.
3. The method as in claim 1 , wherein the precoding is over wideband.
4. The method as in claim 1 , wherein the set of parallel channels is a set of orthogonal frequency division multiplexing (OFDM) tones.
5. The method as in claim 1 , wherein the data transmission is downlink.
6. A mobile communications system for data transmission, the mobile communications system comprising:
a selection unit to select a set of parallel channels;
a first processor to determine transmission rank; and
a second processor to determine a precoding matrix of the transmission rank for the set of parallel channels,
wherein the precoding matrix is formed by applying householder transformation to a vector to make a matrix and selecting one or more columns from the matrix, and
wherein the householder transformation is defined by the following formula:
HH
(
x
)
=
I
-
2
xx
*
x
2
,
where x is the vector, I is an identity matrix, x* is Hermitian conjugate of x, and ∥x∥ is norm of x.
7. The mobile communications system as in claim 6 , further comprising:
a feeding back unit to feed back an indication of the precoding matrix to a base station.
8. The mobile communications system as in claim 6 , wherein the precoding is over wideband.
9. The mobile communications system as in claim 6 , wherein the set of parallel channels is a set of orthogonal frequency division multiplexing (OFDM) tones.
10. The mobile communications system as in claim 6 , wherein the data transmission is downlink.
11. A method implemented in a base station used in a mobile communications system for data transmission, the method comprising:
receiving an indication of a precoding matrix from a user equipment,
wherein the precoding matrix is determined for a set of parallel channels,
wherein the precoding matrix is formed by applying householder transformation to a vector to make a matrix and selecting one or more columns from the matrix, and
wherein the householder transformation is defined by the following formula:
HH
(
x
)
=
I
-
2
xx
*
x
2
,
where x is the vector, I is an identity matrix, x* is Hermitian conjugate of x, and ∥x∥ is norm of x.
12. The method as in claim 11 , further comprising:
receiving from a user equipment a feedback to feed back an indication of the precoding matrix to the base station.
13. The method as in claim 11 , wherein the precoding is over wideband.
14. The method as in claim 11 , wherein the set of parallel channels is a set of orthogonal frequency division multiplexing (OFDM) tones.
15. The method as in claim 11 , wherein the data transmission is downlink.