System and Method for Channel Estimation in Wireless Communications Systems

• US 20110110252A1
• Filed: 11/05/2010
• Published: 05/12/2011
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Panah, Ali Yazdan, Kwon, Young Hoon
• Granted Patent: US 8,817,687 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 7/15585 by interference cancellation
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 25/03006 Arrangements for removing intersymbol interference
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A system and method for channel estimation in wireless communications systems are provided. A method for operations at a first communications device includes computing an estimate of a channel between the first communications device and a second communications device based on pilot signals transmitted from the second communications device, removing self-interference from a composite transmission relayed from a relay node, and detecting information contained in the transmissions from the second communications device from the composite transmission based on the estimate of the channel. The composite transmission includes transmissions from the first communications device and transmissions from the second communications device.

Claims

1. A method for operations at a first communications device, the method comprising:

computing an estimate of a channel between the first communications device and a second communications device based on pilot signals transmitted from the second communications device;

removing self-interference from a composite transmission relayed to the first communications device from a relay node, wherein the composite transmission comprises transmissions from the first communications device and transmissions from the second communications device; and

detecting information contained in the transmissions from the second communications device from the composite transmission based on the estimate of the channel.

2. The method of claim 1, wherein computing an estimate of a channel is further based on a transmission from the first communications device.

3. The method of claim 2, wherein the transmission from the first communications device comprises information.

4. The method of claim 2, wherein the first communications device and the second communications device are operating in a non-overlapping estimation mode.

5. The method of claim 4, further comprising:

determining if a transmission from the first communications device comprises pilot signals; and

buffering the transmission from the second communications device if the transmission from the first communications device comprises pilot signals,

wherein the transmission from the second communications device is not buffered if the transmission from the first communications device does not comprise pilot signals.

6. The method of claim 5, further comprising detecting information contained in the buffered transmission from the second communications device if the transmission from the first communications device comprises pilot signals.

7. The method of claim 6, wherein the detecting information contained in the buffered transmission occurs prior to the detecting information contained in the transmissions from the second communications device.

8. The method of claim 6, further comprising removing self-interference from the buffered transmission prior to detecting information contained in the buffered transmission from the second communications device.

9. The method of claim 5, wherein the buffering the transmission occurs while the second communications device is transmitting pilot signals, and wherein the buffering the transmission stops once the second communications device stops transmitting pilot signals.

10. The method of claim 1, wherein the computing of the estimate of the channel is further based on pilot signals transmitted from the second communications device and pilot signals transmitted from the first communications device.

11. The method of claim 10, wherein the computing of the estimate of the channel based on pilot signals transmitted from the second communications device and pilot signals transmitted from the first communications device occurs before the first communications device stops transmitting pilot signals.

12. The method of claim 1, wherein computing an estimate comprises using least squares estimation on the composite transmission.

13. The method of claim 1, wherein removing self-interference occurs prior to detecting information.

14. The method of claim 1, wherein detecting information occurs after the second communications device stops transmitting pilot signals.

15. The method of claim 14, wherein communications occur in a frame basis, and wherein detecting information continues until an end of a frame is reached.

16. The method of claim 1, wherein the first communications device and the second communications device are operating in an unequal estimation mode.

17. A communications device comprising:

a channel estimator configured to estimate a channel between the communications device and a remote communications device based on pilot signals transmitted from the remote communications device;

a self-interference remover coupled to the channel estimator, the self-interference remover configured to remove self-interference from a composite transmission related to the communications device from a relay node, wherein the composite transmission comprises transmissions from the communications device and transmissions from the remote communications device; and

a data detector coupled to the self-interference remover and to the channel estimator, the data detector configured to detect information contained in transmissions from the remote communications device from the composite transmission based on the estimate of the channel.

18. The communications device of claim 17, wherein the channel estimator is further configured to compute the estimate of the channel based on transmissions from the communications device.

19. The communications device of claim 18, wherein the communications device is operating in a non-overlapping estimation mode, and the communications device further comprises:

a decision unit configured to determine if a transmission from the communications device comprises pilot signals; and

a buffer coupled to the decision unit, the buffer configured to buffer a transmission from the remote communications device if the decision unit determined that the transmission from the communications device comprises pilot signals.

20. The communications device of claim 19, wherein the data detector is further configured to detect information contained in the buffered transmission from the remote communications device.

21. A communications device comprising:

a channel estimate unit configured to estimate a channel between the communications device and a remote communications device based on a composite transmission comprising transmissions from the communications device and the remote communications device;

a data detect unit coupled to the channel estimate unit, the data detect unit configured to detect information contained in the composite transmission based on the estimate of the channel; and

a buffer coupled to the data detect unit, the buffer configured to buffer the composite transmission based on an operating mode of the communications device.

22. The communications device of claim 21, wherein the data detect unit is further configured to remove self-interference from the composite transmission.

23. The communications device of claim 21, wherein the data detect unit is further configured to detect information contained in the buffered composite transmission.

24. The communications device of claim 21, further comprising a control unit coupled to the channel estimate unit, to the data detect unit, and to the buffer, the control unit configured to generate a control signal based on the composite transmission and on an operating mode of the communications device.