Interference cancellation in MIMO same channel full-duplex transceivers

Patent metadata

Field	Value
Publication number	US-9966983-B2
Application number	US-201414461224-A
Country	US
Kind code	B2
Filing date	Aug 15, 2014
Priority date	Aug 15, 2014
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

Same-channel full-duplex communications can be adapted for multiple-input multiple-output (MIMO) processing in order to derive increased signal performance through the exploitation of spatial diversity. Strong interference components from transmissions over multiple local antennas can be removed from a received radio signal to allow array and diversity gain benefits of MIMO to be enjoyed in same-channel full-duplex communications. More specifically, baseband samples of two or more MIMO transmission signals may be used to perform channel estimation on a received radio signal by correlating the baseband signals with the radio signal to estimate interference channels associated with the MIMO transmission signals. The estimated interference channels are used to subtract corresponding interference components from the received radio signals.

First claim

What is claimed:

1. A method for receiving data in a multiple-input multiple-output (MIMO) full-duplex communication channel, the method comprising:
receiving, by a device, a radio signal over a first antenna of a multi-antenna array, the radio signal including a received signal component corresponding to a communications signal being received over the MIMO full-duplex communication channel;
obtaining baseband samples of transmission signals communicated over the MIMO full-duplex communication channel, the transmission signals including at least a first transmission signal emitted over the first antenna and a second transmission signal emitted over a second antenna of the multi-antenna array, wherein the baseband samples include a first baseband sample corresponding to the first transmission signal and a second baseband sample corresponding to the second transmission signal;
performing channel estimation for the radio signal in accordance with the baseband samples to generate an interference-cancellation signal, the interference-cancellation signal including at least a first interference component corresponding to the first transmission signal and a second interference component corresponding to the second transmission signal, the first transmission signal being transmitted over the same antenna as the radio signal was received, the first transmission signal and the radio signal being non-orthogonal in the time, frequency, and code domains, wherein performing channel estimation for the radio signal in accordance with the baseband samples comprises correlating the second baseband sample with the radio signal to estimate a first interference channel associated with the second transmission signal, and deriving the second interference component from the first interference channel; and
subtracting the interference cancellation signal from the radio signal to at least partially isolate the received signal component from interference in the radio signal.

2. The method of claim 1 , wherein the communications signal, the first transmission signal, and the second transmission signal are communicated over common network resources of the MIMO full-duplex communication channel.

3. The method of claim 1 , wherein the first interference channel corresponds to an air interface extending from the second antenna of the multi-antenna array to the first antenna of the multi-antenna array.

4. The method of claim 3 , wherein the first antenna and the second antenna are used to perform a MIMO transmission over the same network resource on which the communications signal is received.

5. The method of claim 1 , wherein performing channel estimation for the radio signal in accordance with the baseband samples further comprises:
applying a least-squares algorithm to the radio signal in accordance with at least the first sample and the second sample to obtain at least a second interference channel associated with the first transmission signal and the first interference channel associated with the second interference channel; and
estimating the interference-cancellation signal in accordance with at least the first interference channel and the second interference channel.

6. The method of claim 1 , wherein performing channel estimation for the radio signal in accordance with the baseband samples further comprises:
creating a data matrix from the baseband samples; and
estimating the interference cancellation signal in accordance with the estimated first interference channel.

7. The method of claim 6 , wherein estimating the interference cancellation signal in accordance with the data matrix comprises:
performing least squares estimation on the data matrix and samples of the received radio signal to estimate the first interference channel.

8. The method of claim 7 , wherein estimating the interference cancellation signal in accordance with the data matrix comprises:
performing singular-value decomposition (SVD) on the data matrix or calculating the Moore-Penrose inverse of the data matrix to estimate the first interference channel.

9. The method of claim 1 , wherein the multi-antenna array includes K antennas, where K is an integer greater than two, and wherein performing channel estimation for the radio signal comprises:
correlating baseband samples of K transmission signals with the radio signal to estimate K interference channels, the K transmission signals being emitted simultaneously over the K antennas of the multi-antenna array as part of a MIMO transmission signal; and
deriving the interference cancellation signal from the K interference channels.

10. The method of claim 1 , wherein performing channel estimation for the radio signal in accordance with the baseband samples further comprises:
correlating the first baseband sample with the radio signal to estimate a second interference channel associated with the first transmission signal; and
deriving the first interference component from the second interference channel.

11. The method of claim 1 , wherein performing channel estimation for the radio signal in accordance with the baseband samples further comprises estimating a first interference channel using an auxiliary receiver and an auxiliary transmitter coupled to the first antenna, and wherein subtracting the interference cancellation signal from the radio signal comprises subtracting the interference cancellation signal from the radio signal in analog domain using the auxiliary receiver and the auxiliary transmitter.

12. A communications device adapted for communicating via multiple-input multiple-output (MIMO) full-duplex communication channel, the communications device comprising:
a processor; and
a computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
receive a radio signal over a first antenna of a multi-antenna array, the radio signal including a received signal component corresponding to a communications signal received over the MIMO full-duplex communication channel;
obtain baseband samples of transmission signals communicated over the MIMO full-duplex communication channel, the transmission signals including at least a first transmission signal emitted over the first antenna and a second transmission signal emitted over a second antenna of the multi-antenna array, wherein the baseband samples include a first baseband sample corresponding to the first transmission signal and a second baseband sample corresponding to the second transmission signal;
perform channel estimation for the radio signal in accordance with the baseband samples to generate an interference cancellation signal, the interference cancellation signal including at least a first interference component corresponding to the first transmission signal and a second interference component corresponding to the second transmission signal, the first transmission signal being transmitted over the same antenna as the radio signal was received, the first transmission signal and the radio signal being non-orthogonal in the time, frequency, and code domains; and
subtract the interference cancellation signal from the radio signal to at least partially isolate the received signal component from interference in the radio signal,
wherein the instructions to perform channel estimation for the radio signal in accordance with the baseband samples include instructions to estimate a first interference channel associated with the second transmission signal in accordance with the second baseband sample and samples of the received radio signal, and derive the second interference component from the first interference channel.

13. The commun

Assignees

• Huawei Tech Co Ltd

Inventors

• Moher Michael

Classifications

• H04B7/0413

  MIMO systems · CPC title

• H04B1/525

  with means for reducing leakage of transmitter signal into the receiver · CPC title

• H04B1/12 Primary

  Neutralising, balancing, or compensation arrangements · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H04B1/0475 Primary

  with means for limiting noise, interference or distortion (H04B1/0483 takes precedence) · CPC title