Method and apparatus for mitigating interference in a wireless network through use of transmit beamforming

Patent metadata

Field	Value
Publication number	US-9325540-B2
Application number	US-201414249760-A
Country	US
Kind code	B2
Filing date	Apr 10, 2014
Priority date	Apr 10, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

In a method for reducing interference in wireless communications, a beamforming matrix is determined at a first communication device based on an estimate of a multiple input, multiple output (MIMO) communication channel between the first communication device and a second communication device. Both the first communication device and the second communication device belong to a first wireless network. Alternatively, the beamforming matrix may be generated based on the estimate of the MIMO communication channel and received at the first communication device. The beamforming matrix is used at the first communication device for the purpose of reducing interference to a second wireless network. where the interference is caused by the first communication device transmitting to the second communication device via the MIMO communication channel.

First claim

What is claimed is:

1. A method for reducing interference in wireless communications, the method comprising:
at least one of
i) determining, at a first communication device, a beamforming matrix based on an estimate of a multiple input, multiple output (MIMO) communication channel between the first communication device and a second communication device, wherein the first communication device and the second communication device belong to a first wireless network, wherein the beamforming matrix is determined without using channel estimate information corresponding to a communication channel to any third communication device in a second wireless network, and wherein the second wireless network omits the first communication device, or
ii) receiving, at the first communication device, the beamforming matrix, the beamforming matrix having been generated a) based on the estimate of the MIMO communication channel and b) without using channel estimate information corresponding to the communication channel to any third communication device in the second wireless network;

the method further comprising:
determining, at the first communication device, at least one of i) whether a distance between the first communication device and one of the third communication devices is less than a distance threshold and ii) whether transmissions from the second wireless network meet a signal strength criteria;
in response to determining at least one of i) that the distance is less than a distance threshold and ii) that the transmissions from the second wireless network meet the signal strength criteria, determining that the first communication device is near to the second wireless network and that transmissions from the first communication device in the first wireless network are producing interference to the second wireless network;
determining, at the first communication device, whether the first communication device receives from any third communication device in the second wireless network via a communication link a request for the first communication device to reduce interference to the second wireless network, wherein the request is in response to the produced interference to the second wireless network;
in response to determining that transmissions from the first communication device in the first wireless network are producing interference to the second wireless network, reducing, by using the beamforming matrix at the first communication device, the interference to the second wireless network, wherein the interference is generated by the first communication device transmitting to the second communication device via the MIMO communication channel;
coordinating, at the first communication device, with an access point in the second wireless network so that the first communication device uses a first beamforming matrix for a first downlink transmission when the access point is scheduled to perform a second downlink transmission to a client communication device in the second wireless network; and
coordinating, at the first communication device, with the access point in the second wireless network so that the first communication device schedules one or more first uplink transmissions in the first wireless network at times different than when the access point schedules one or more second uplink transmissions in the second wireless network;

wherein
the one or more first uplink transmissions are one or more transmissions from the second communication device to the first communication device, and
the one or more second uplink transmissions are one or more transmissions from the fourth communication device or from one or more other client communication devices in the second wireless network to the access point.

2. The method of claim 1 , further comprising determining, at the first communication device, the estimate of the MIMO communication channel.

3. The method of claim 1 , wherein determining the estimate of the MIMO communication channel includes receiving the estimate of the MIMO communication channel from the second communication device.

4. The method of claim 1 , wherein the MIMO communication channel is below 6 GHz.

5. The method of claim 4 , wherein the MIMO communication channel is above 2 GHz.

6. The method of claim 1 , wherein the second wireless network omits the second communication device.

7. An apparatus corresponding to a first communication device, the apparatus comprising:
a network interface including
i) a media access control (MAC) processing unit, and
ii) a physical layer (PHY) processing unit coupled to the MAC processing unit;

wherein the PHY processing unit is configured to at least one of
i) determine a beamforming matrix based on an estimate of a multiple input, multiple output (MIMO) communication channel between the first communication device and a second communication device, wherein the first communication device and the second communication device belong to a first wireless network, wherein the beamforming matrix is determined without using channel estimate information corresponding to a communication channel to any third communication device in a second wireless network, and wherein the second wireless network omits the first communication device, or
ii) receive the beamforming matrix, the beamforming matrix having been generated a) based on the estimate of the MIMO communication channel and b) without using channel estimate information corresponding to the communication channel to any third communication device in the second wireless network; and

wherein the network interface is configured to
determine at least one of i) whether a distance between the first communication device and one of the third communication devices is less than a distance threshold and ii) whether transmissions from the second wireless network meet a signal strength criteria,
in response to a determination of at least one of i) that the distance is less than a distance threshold and ii) that the transmissions from the second wireless network meet the signal strength criteria, determine that the first communication device is near to the second wireless network and that transmissions from the first communication device in the first wireless network are producing interference to the second wireless network,
determine whether the first communication device receives from any third communication device in the second wireless network via a communication link a request for the first communication device to reduce interference to the second wireless network,
in response to a determination that the request for the first communication device to reduce interference to the second wireless network is received, determine that transmissions from the first communication device in the first wireless network are producing interference to the second wireless network,
in response to a determination that transmissions from the first communication device in the first wireless network are producing interference to the second wireless network, reduce, by use of the beamforming matrix, the interference to the second wireless network, wherein the interference is generated by the first communication device transmitting to the second communication device,
use the beamforming matrix for the purpose of reducing interference to the second wireless network caused by the first communication device transmitting to the second communication device via the MIMO communication channel,
coordinate with an access point in the second wireless network so that the first communication device uses a first beamforming matrix for a first downlink transmission when the access point is scheduled to perform a second downlink transmission to a client communication device in the second wireless network, and
coordinate with the ac

Assignees

• Marvell World Trade Ltd

Inventors

• Zhang Hongyuan
• Nabar Rohit U
• Li Pen Chung

Classifications

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title

• H04B7/0456 Primary

  Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting · CPC title

• H04L25/03904 Primary

  cooperative design, e.g. exchanging of codebook information between base stations · CPC title

• H04L25/03942

  switching between different codebooks · CPC title

• H04L25/0204

  of multiple channels · CPC title