Method for the multi-antenna transmission of a linearly-precoded signal, corresponding devices, signal and reception method
View Patent ↗An embodiment of invention relates to a method for the transmission of a signal formed by vectors, each vector comprising N source symbols to be transmitted, using M transmission antennas, wherein M is greater than or equal to 2. The method comprises the following steps: linearly precoding the signal using a matrix product of a source matrix formed by vectors that are organized in successive lines by a linear precoding matrix, delivering a precoded matrix; and successively transmitting precoded vectors corresponding to columns of said precoded matrix, the M symbols of each precoded vector being distributed to the M antennas.
1. A method for sending a signal formed by vectors, each vector comprising N source symbols to be sent, and implementing M transmit antennas where M is greater than or equal to 2, the method comprising:
linearly precoding said signal, implementing a matrix product of a source matrix, formed by said vectors organized in successive rows, by a linear precoding matrix, delivering a precoded matrix, and
sending precoded vectors corresponding to columns of said precoded matrix successively, wherein each precoded vector has M symbols, which have undergone a precoding by a same column of the linear precoding matrix and are distributed over said M antennas.
2. The method according to claim 1 , wherein the precoding matrix comprises a block matrix.
3. The method according to claim 1 , wherein the precoding matrix comprises a unitary matrix having a size greater than or equal to M.
4. The method according to claim 1 , wherein the precoding matrix has the form:
Θ
L
=
2
L
·
[
Θ
L
/
2
Θ
L
/
2
Θ
L
/
2
-
Θ
L
/
2
]
T
with
Θ
2
=
⌊
ⅇ
ⅈθ
1
cos
η
ⅇ
ⅈθ
2
sin
η
-
ⅇ
-
ⅈθ
2
sin
η
ⅇ
-
ⅈθ
1
cos
η
⌋
and
η
=
π
4
+
k
π
2
,
θ
2
=
θ
1
-
π
2
,
and for iε[1,2],
θ
i
=
π
4
+
k
′
π
2
where k, k′ are relative integers.
5. A method for receiving a signal sent on M transmit antennas where M is greater than or equal to 2, implementing P receiver antennas, where P greater than or equal to 2, wherein the method comprises:
receiving reception vectors on said P antennas, which are distributed by columns in a reception matrix, each reception vector comprises P received symbols distributed on said P receiver antennas and corresponding symbols having undergone a precoding by a same column of a linear precoding matrix at sending,
processing said reception matrix, comprising multiplying by a linear de-precoding matrix representing the linear precoding matrix used at sending, so as to obtain a de-precoded matrix by which it is possible to extract an estimation of source symbols sent in the signal.
6. The method according to claim 5 , wherein the de-precoding matrix is the conjugate transpose matrix of said precoding matrix.
7. The method according to claim 6 , wherein said sent signal is conveyed between said M transmit antennas and said P receiver antennas by a transmission channel, said reception matrix is multiplied, during said processing, by a matrix representing the inverse of said transmission channel, so as to obtain a matrix of estimated symbols sent, and wherein said matrix of estimated symbols sent is then multiplied by the de-precoding matrix.
8. The method according to claim 6 , wherein the method comprises a preliminary step of detecting said M transmit antennas implementing a successive cancellation algorithm.
9. The method according to claim 5 , wherein said sent signal is conveyed between said M transmit antennas and said P receiver antennas by a transmission channel, and said de-precoding matrix is an inverse matrix of a total matrix associating the matrix of said channel and said linear precoding matrix.
10. The method according to claim 9 , wherein said de-precoding matrix is determined by implementation of a Cholesky decomposition algorithm.
11. A method comprising:
generating a signal comprising precoded vectors to be sent successively on M transmit antennas, where M is greater than or equal to 2, wherein the precoded vectors correspond to columns of a precoded matrix and each precoded vector has M symbols, which have undergone a precoding by a same column of the linear precoding matrix and are distributed on said M antennas,
and wherein the precoded matrix is obtained by a matrix product of a linear precoding matrix and a source matrix, formed by source vectors each comprising N source symbols to be sent, said source vectors being organized in said source matrix in successive rows, and
sending the signal.
12. A device for sending a signal formed by vectors each comprising N source symbols to be sent, and implementing M transmit antennas, where M is greater than or equal to 2, the device comprising:
means of linearly precoding said signal, implementing a matrix product of a source matrix, formed by said vectors organized in successive rows, by a linear precoding matrix, delivering a precoded matrix, and
means for successively sending precoded vectors corresponding to columns of said precoded matrix, wherein each precoded vector has M symbols, which have undergone a precoding by a same column of the linear precoding matrix and are distributed over said M antennas.
13. A device for receiving a signal sent on M transmit antennas, where M is greater than or equal to 2, said device comprising:
P receiver antennas, where P is greater than or equal to 2,
means of reception, on said P antennas, of reception vectors, and means of distribution by columns of said reception vectors in a reception matrix, wherein each reception vector comprises P received symbols distributed on said P receiver antennas and corresponding symbols having undergone a precoding by a same column of a linear precoding matrix at sending, and
means of processing of said reception matrix, comprising means of multiplying by a linear de-precoding matrix representing the linear precoding matrix used at sending, so as to obtain a de-precoded matrix by which it is possible to extract an estimation of source symbols sent.