Method and device for transmitting signal

• US 9,484,999 B2
• Filed: 06/05/2014
• Issued: 11/01/2016
• Est. Priority Date: 12/05/2011
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Chen, Zhi, Zeng, Junjie, Li, Lingxiang, Wang, Yi
• Primary Examiner(s): Choi, Eunsook
• Application Number:
  US14/297,022
• Publication Number:
  US 20140307664A1
• Time in Patent Office: 880 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0865 Independent weighting, i.e. weights based on own antenna reception parameters

Abstract

Embodiments of the present invention provide a method and device for transmitting signal. The method includes: obtaining a downlink beamforming matrix; and using a conjugate transposed matrix of the downlink beamforming matrix as an uplink beamforming matrix for processing uplink signal. In the embodiments of the present invention, the conjugate transposed matrix of the downlink beamforming matrix may be used as the uplink beamforming matrix for processing uplink signal, which can simplify design of the uplink beamforming matrix and thereby reduce complexity of the system.

Claims

1. A method for transmitting signal, comprising:

obtaining a downlink beamforming matrix by optimizing a quantity with respect to the beamforming matrix for a channel matrix between a first communication device and a second communication device; and

using a conjugate transposed matrix of the downlink beamforming matrix as an uplink beamforming matrix for processing an uplink signal,

wherein the first communication device is a macro base station, and the second communication device is a relay station, a micro base station, or a user terminal.

2. The method according to claim 1, wherein:

the obtaining a downlink beamforming matrix comprises;

obtaining, by the first communication device and as the downlink beamforming matrix, a downlink transmit beamforming matrix based on the optimized quantity being a signal to leakage plus noise ratio at the second communication device; and

the using a conjugate transposed matrix of the downlink beamforming matrix as an uplink beamforming matrix for processing uplink signal comprises;

using, by the first communication device, a conjugate transposed matrix of the downlink transmit beamforming matrix as an uplink receive beamforming matrix for processing uplink signal received from the second communication device.

3. The method according to claim 2, wherein the obtaining, by the first communication device, the downlink transmit beamforming matrix based on a signal to leakage plus noise ratio at the second communication device comprises:

obtaining, by the first communication device according to a covariance matrix of an additive white Gaussian noise vector at the second communication device and the channel matrix from the first communication device to the second communication device, the downlink transmit beamforming matrix that maximizes the signal to leakage plus noise ratio at the second communication device.

4. The method according to claim 3, wherein the obtaining the downlink transmit beamforming matrix that maximizes the signal to leakage plus noise ratio at the second communication device comprises:

obtaining, by the first communication device, the downlink transmit beamforming matrix through a following formula;

5. The method according to claim 4, wherein:

when d=1, the downlink transmit beamforming matrix is an eigenvector corresponding to a maximum generalized eigenvalue of a matrix pair

6. The method according to claim 1, wherein:

the obtaining the downlink beamforming matrix comprises;

obtaining, by the second communication device and as the downlink beamforming matrix, a downlink receive beamforming matrix based on the optimized quantity being a signal to interference plus noise ratio at the second communication device; and

the using a conjugate transposed matrix of the downlink beamforming matrix as an uplink beamforming matrix for processing uplink signal comprises;

using, by the second communication device, a conjugate transposed matrix of the downlink receive beamforming matrix as an uplink transmit beamforming matrix for processing uplink signal sent to the first communication device.

7. The method according to claim 6;

wherein the obtaining, by the second communication device, the downlink receive beamforming matrix based on the signal to interference plus noise ratio at the second communication device comprises;

obtaining, by the second communication device according to an interference plus noise covariance matrix at the second communication device and an equivalent channel matrix from the first communication device to the second communication device, the downlink receive beamforming matrix that maximizes the signal to interference plus noise ratio at the second communication device.

8. The method according to claim 7, wherein the obtaining the downlink receive beamforming matrix that maximizes the signal to interference plus noise ratio at the second communication device comprises:

obtaining, by the second communication device, the downlink receive beamforming matrix through a following formula;

9. The method according to claim 2, wherein the using the conjugate transposed matrix of the downlink beamforming matrix as the uplink beamforming matrix for processing uplink signal comprises:

in the case of duality of a transceiver filter of the first communication device and duality of a transceiver filter of the second communication device, using the conjugate transposed matrix of the downlink beamforming matrix as the uplink beamforming matrix for processing uplink signal.

10. A device for transmitting signal, comprising:

at least one hardware processor; and

a memory containing instruction which control the at least one hardware processor to implement;

an obtaining module, configured to obtain a downlink transmit beamforming matrix by optimizing a quantity with respect to the beamforming matrix for a channel matrix between a first communication device and a second communication device; and

a processing module, configured to use a conjugate transposed matrix of the downlink transmit beamforming matrix as an uplink receive beamforming matrix for processing uplink signal.

11. The device according to claim 10, wherein:

the device is the first communication device;

the obtaining module is configured to obtain the downlink transmit beamforming matrix based on the quantity being a signal to leakage plus noise ratio at the second communication device; and

the processing module is configured to use the conjugate transposed matrix of the downlink transmit beamforming matrix as the uplink receive beamforming matrix for processing uplink signal received from the second communication device.

12. The device according to claim 11, wherein:

the obtaining module is configured to obtain, according to a covariance matrix of an additive white Gaussian noise vector at the second communication device and a channel matrix from the first communication device to the second communication device, a downlink transmit beamforming matrix that maximizes the signal to leakage plus noise ratio at the second communication device.

13. The device according to claim 12, wherein the obtaining module is configured to obtain the downlink transmit beamforming matrix through a following formula:

14. The device according to claim 13, wherein:

when d=1, the downlink transmit beamforming matrix is an eigenvector corresponding to a maximum generalized eigenvalue of a matrix pair

15. The device according to claim 11, wherein the processing module is configured to:

in the case of duality of a transceiver filter of the first communication device and duality of a transceiver filter of the second communication device, use a conjugate transposed matrix of a downlink beamforming matrix as an uplink beamforming matrix for processing uplink signal.

16. The device according to claim 11, wherein the first communication device is a macro base station, and the second communication device is a relay station, a micro base station, or a user terminal.

17. A device for transmitting signal, comprising:

at least one hardware processor; and

a memory containing instruction which control the at least one hardware processor to implement;

an obtaining module, configured to obtain a downlink receive beamforming matrix by optimizing a quantity with respect to the beamforming matrix for a channel matrix between a first communication device and a second communication device; and

a processing module, configured to use a conjugate transposed matrix of the downlink receive beamforming matrix as an uplink transmit beamforming matrix for processing uplink signal.

18. The device according to claim 17, wherein:

the device is the second communication device;

the obtaining module is configured to obtain the downlink receive beamforming matrix based on the quantity being a signal to interference plus noise ratio at the second communication device; and

the processing module uses the conjugate transposed matrix of the downlink receive beamforming matrix as the uplink transmit beamforming matrix for processing uplink signal sent to a first communication device.

19. The device according to claim 18, wherein:

the obtaining module is configured to obtain, according to an interference plus noise covariance matrix at the second communication device and an equivalent channel matrix from the first communication device to the second communication device, a downlink receive beamforming matrix that maximizes the signal to interference plus noise ratio at the second communication device.

20. The device according to claim 19, wherein the obtaining module is configured to obtain the downlink receive beamforming matrix through a following formula:

21. The device according to claim 18, wherein the processing module is configured to:

in the case of duality of a transceiver filter of the first communication device and duality of a transceiver filter of the second communication device, use a conjugate transposed matrix of a downlink beamforming matrix as an uplink beamforming matrix for processing uplink signal.

22. The device according to claim 18, wherein the first communication device is a macro base station, and the second communication device is a relay station, a micro base station, or a user terminal.