MULTI-ANTENNA RELAY WITH SELF-INTERFERENCE CANCELLATION

• US 20100272005A1
• Filed: 07/03/2006
• Published: 10/28/2010
• Est. Priority Date: 07/03/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Larsson, Peter, Prytz, Mikael
• Granted Patent: US 8,244,190 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04B 7/15564 Relay station antennae loop interference reduction

Abstract

A wireless relay node (100) comprises a receiving side (110) and a transmitting side (120) adapted for concurrent reception and transmission of an information stream, and at least one of the two sides has multiple antennas for multi-antenna operation. In the internal design, the wireless relay node is further configured (130) for cancelling signal feedback from a multi-antenna dependent feedback channel from the transmitting side to the receiving side based on an N×M dimensional filter matrix (135) dependent on the multi-antenna dependent feedback channel, where at least one of N and M is greater than 1. In this way, self-interference cancellation of a multi-antenna dependent feedback signal from the output to the input of the wireless relay node is effectively obtained.

Claims

1. A wireless relay node comprising:

a receiving side and a transmitting side for concurrent reception and transmission of an information stream, at least one of said receiving side and said transmitting side having multiple antennas;

means for cancelling signal feedback from a multi-antenna dependent feedback channel from said transmitting side to said receiving side based on a N×

M dimensional filter matrix dependent on said multi-antenna dependent feedback channel, where at least one of N and M is greater than 1.

2. The wireless relay node of claim 1, wherein said multi-antenna dependent feedback channel is represented by a N₁×

N₂ dimensional channel matrix, where at least one of N₁ and N₂ is greater than 1.

3. The wireless relay node of claim 1, wherein said filter matrix is implemented in a filter arranged in an internal feedback path in connection with a forward path between said receiving side and said transmitting side of said relay node.

4. The wireless relay node of claim 3, wherein said relay node further comprises means for signal processing arranged in said forward path, and said N×

M dimensional filter matrix is also dependent on a transfer function of said signal processing means.

5. The wireless relay node of claim 4, wherein said signal processing means comprises at least one of an antenna weight matrix, and said N×

M dimensional filter matrix is dependent on a transfer function of said at least one antenna weight matrix.

6. The wireless relay node of claim 5, wherein said at least one antenna weight matrix includes at least one of an antenna weight matrix for said receiving side and an antenna weight matrix for said transmitting side.

7. The wireless relay node of claim 6, wherein said at least one antenna weight matrix includes an antenna weight matrix for said receiving side, and said receiving side antenna weight matrix is adapted at least partly in dependence on the channel matrix between a transmitting node and said relay node.

8. The wireless relay node of claim 7, wherein said receiving side antenna weight matrix is adapted for suppressing interference from other nodes.

9. The wireless relay node of claim 6, wherein said at least one antenna weight matrix includes an antenna weight matrix for said transmitting side, and said transmitting side antenna weight matrix is adapted at least partly in dependence on the channel matrix between said relay node and a receiving node.

10. The wireless relay node of claim 9, wherein said transmitting side antenna weight matrix is adapted for interference mitigation.

11. The wireless relay node of claim 6, wherein said at least one antenna weight matrix includes an antenna weight matrix for said receiving side and an antenna weight matrix for said transmitting side and said antenna weight matrices are selected jointly to optimize performance of communication between a transmitting node and a receiving node via said relay node.

12. The wireless relay node of claim 4, wherein said signal processing means is operable for performing at least one of beamforming, suppression of external interference, mitigation of generated interference, noise suppression, rank preservation, and optimization of performance of communication between a transmitting node and a receiving node via said relay node.

13. The wireless relay node of claim 1, wherein said relay node further comprises:

means for determining a channel matrix of said feedback channel based on a pilot signal inserted in said relay node; and

means for adapting said N×

M dimensional filter matrix based on said feedback channel matrix.

14. The wireless relay node of claim 1, wherein said receiving side and said transmitting side are configured for operation concurrently within the same frequency band.

15. The wireless relay node of claim 14, wherein said relay node is a multi-antenna on-frequency repeater.

18. A relaying network comprising a wireless relay node according to any of the preceding claims.

16. A wireless relay node comprising:

a receiving side and a transmitting side for concurrent reception and transmission of an information stream, said receiving side and said transmitting side having multiple antennas;

means for receiving a Multiple Input Multiple Output;

MIMO signal representative of said information stream at said receiving side with a dimensionality greater than 1;

means for processing said MIMO signal such that the dimensionality of the processed signal for transmission at the transmitting side is at least greater than 1.

17. A wireless relay node comprising:

a receiving side and a transmitting side for concurrent reception and transmission of an information stream, said receiving side and said transmitting side having multiple antennas;

means for receiving a Multiple Input Multiple Output;

MIMO signal representative of said information stream at said receiving side, said received MIMO signal having multiple MIMO sub-streams;

means for processing said received MIMO signal such that the number of MIMO sub-streams of the processed signal for transmission at the transmitting side is at least greater than 1.

19. A method of determining a self-interference cancellation filter for a wireless relay node having a receiving side and a transmitting side for concurrent reception and transmission of an information stream, wherein said method comprises the steps of:

determining a channel matrix of a multi-antenna dependent feedback channel from said transmitting side to said receiving side, at least one of said receiving side and said transmitting side having multiple antennas; and

determining said self-interference cancellation filter as a N×

M dimensional filter matrix in dependence on said feedback channel matrix, where at least one of N and M is greater than 1.

20. The method of claim 19, wherein said wireless relay node is an on-frequency relay node.

21. A self-interference cancellation filter for a wireless relay node, said relay node having a receiving side and a transmitting side for concurrent reception and transmission of an information stream, wherein said filter is based on a N×

M dimensional filter matrix that is dependent on a multi-antenna dependent feedback channel from said transmitting side to said receiving side of said relay node, where at least one of N and M is greater than 1.

22. The filter of claim 21, wherein said wireless relay node is an on-frequency relay node.