Interference Avoidance for Beamforming Transmissions in Wireless Communication Devices and Systems

• US 20150030094A1
• Filed: 07/24/2014
• Published: 01/29/2015
• Est. Priority Date: 07/26/2013
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Zhang, Hongyuan
• Granted Patent: US 9,306,645 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• 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 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0621 Feedback content
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/03904 cooperative design, e.g. exchanging of codebook information between base stations
• CPC Class Codes: H04L 25/0391 construction details of matrices
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

Systems and techniques for interference avoidance beamforming transmissions are described. A described technique includes accessing, at a first device, data for transmission to a second device; performing, at the first device, a channel sounding process with a third device to obtain channel feedback regarding a wireless channel between the first device and the third device; determining a steering matrix based on the channel feedback to reduce interference leakage received by the third device during a beamforming transmission from the first device to the second device; and performing, at the first device, the beamforming transmission to the second device based on the data and the steering matrix.

Claims

1. A method comprising:

accessing, at a first device, data for transmission to a second device;

performing, at the first device, a channel sounding process with a third device to obtain channel feedback regarding a wireless channel between the first device and the third device;

determining a steering matrix based on the channel feedback to reduce interference leakage received by the third device during a beamforming transmission from the first device to the second device; and

performing, at the first device, the beamforming transmission to the second device based on (i) the data and (ii) the steering matrix.

2. The method of claim 1, wherein determining the steering matrix comprises:

determining a null steering matrix responsive to the channel feedback, the null steering matrix being based on a null space of a wireless channel matrix associated with the wireless channel.

3. The method of claim 1, wherein determining the steering matrix comprises:

determining a first matrix responsive to the channel feedback, the first matrix being based on a null space of a wireless channel matrix associated with the wireless channel; and

determining a second matrix to improve a performance of the beamforming transmission with respect to the second device, the steering matrix being based on the first matrix and the second matrix.

4. The method of claim 1, wherein the channel sounding process comprises:

transmitting a sounding announcement packet to the third device, the sounding announcement packet comprising an interference avoidance indicator;

transmitting a sounding packet after transmitting the sounding announcement packet; and

receiving the channel feedback from the third device, the channel feedback being based on the sounding packet.

5. The method of claim 4, wherein the steering matrix is based on a null space of a wireless channel matrix that represents channel state information, the channel state information being included in the channel feedback.

6. The method of claim 4, wherein determining the steering matrix comprises determining a null steering matrix based on steering matrix feedback such that columns in the null steering matrix form basis vectors in a null-space of a wireless channel matrix associated with the third device, the steering matrix feedback being included in the channel feedback.

7. The method of claim 1, wherein the channel sounding process comprises:

receiving, at the first device, a sounding announcement packet from the third device, the sounding announcement packet comprising an interference avoidance indicator;

receiving, at the first device, a sounding packet from the third device after receiving the sounding announcement packet; and

determining, at the first device, the channel feedback based on the sounding packet.

8. The method of claim 1, wherein the second device and the third device are associated with different basic service sets, the basic service sets overlapping in a frequency band.

9. An apparatus comprising:

first circuitry configured to access data for transmission to a first device; and

second circuitry configured to (i) control a channel sounding process with a second device to obtain channel feedback regarding a wireless channel between the apparatus and the second device, (ii) determine a steering matrix based on the channel feedback to reduce interference leakage received by the second device during a beamforming transmission from the apparatus to the first device, and (iii) control the beamforming transmission to the first device based on the data and the steering matrix.

10. The apparatus of claim 9, wherein the steering matrix is based on a null steering matrix, and wherein the second circuitry is configured to determine the null steering matrix responsive to the channel feedback, the null steering matrix being based on a null space of a wireless channel matrix associated with the wireless channel.

11. The apparatus of claim 9, wherein the second circuitry is configured to

determine a first matrix responsive to the channel feedback, the first matrix being based on a null space of a wireless channel matrix associated with the wireless channel, and

determine a second matrix to improve a performance of the beamforming transmission with respect to the first device, the steering matrix being based on the first matrix and the second matrix.

12. The apparatus of claim 9, wherein the channel sounding process comprises:

transmitting a sounding announcement packet to the second device, the sounding announcement packet comprising an interference avoidance indicator;

transmitting a sounding packet after transmitting the sounding announcement packet; and

receiving the channel feedback from the second device, the channel feedback being based on the sounding packet.

13. The apparatus of claim 12, wherein the steering matrix is based on a null space of a wireless channel matrix that represents channel state information, the channel state information being included in the channel feedback.

14. The apparatus of claim 12, wherein the steering matrix is based on a null steering matrix, and wherein the second circuitry is configured to determine the null steering matrix based on steering matrix feedback such that columns in the null steering matrix form basis vectors in a null-space of a wireless channel matrix associated with the second device, the steering matrix feedback being included in the channel feedback.

15. The apparatus of claim 9, wherein the channel sounding process comprises:

receiving a sounding announcement packet from the second device, the sounding announcement packet comprising an interference avoidance indicator;

receiving a sounding packet from the second device after receiving the sounding announcement packet; and

determining the channel feedback based on the sounding packet.

16. The apparatus of claim 9, wherein the first device and the second device are associated with different basic service sets, the basic service sets overlapping in a frequency band.

17. A system comprising:

transceiver electronics configured to wirelessly communicate with devices including a first device and a second device; and

processor electronics coupled with the transceiver electronics, configured to (i) access data for transmission to the first device, (ii) control a channel sounding process with the second device to obtain channel feedback regarding a wireless channel between the system and the second device, (iii) determine a steering matrix based on the channel feedback to reduce interference leakage received by the second device during a beamforming transmission from the system to the first device, and (iv) control the beamforming transmission to the first device based on the data and the steering matrix.

18. The system of claim 17, wherein the steering matrix is based on a null steering matrix, and wherein the processor electronics are configured to determine the null steering matrix responsive to the channel feedback, the null steering matrix being based on a null space of a wireless channel matrix associated with the wireless channel.

19. The system of claim 17, wherein the processor electronics are configured to

determine a first matrix responsive to the channel feedback, the first matrix being based on a null space of a wireless channel matrix associated with the wireless channel, and

determine a second matrix to improve a performance of the beamforming transmission with respect to the first device, the steering matrix being based on the first matrix and the second matrix.

20. The system of claim 17, wherein the channel sounding process comprises:

transmitting a sounding announcement packet to the second device, the sounding announcement packet comprising an interference avoidance indicator;

transmitting a sounding packet after transmitting the sounding announcement packet; and

receiving the channel feedback from the second device, the channel feedback being based on the sounding packet.

21. The system of claim 20, wherein the steering matrix is based on a null space of a wireless channel matrix that represents channel state information, the channel state information being included in the channel feedback.

22. The system of claim 20, wherein the steering matrix is based on a null steering matrix, and wherein the processor electronics are configured to determine the null steering matrix based on steering matrix feedback such that columns in the null steering matrix form basis vectors in a null-space of a wireless channel matrix associated with the second device, the steering matrix feedback being included in the channel feedback.

23. The system of claim 17, wherein the channel sounding process comprises:

receiving a sounding announcement packet from the second device, the sounding announcement packet comprising an interference avoidance indicator;

receiving a sounding packet from the second device after receiving the sounding announcement packet; and

determining the channel feedback based on the sounding packet.

24. The system of claim 17, wherein the first device and the second device are associated with different basic service sets, the basic service sets overlapping in a frequency band.