US 9,112,744 B1 · Noise whitening in a WLAN receiver

Abstract

In a method of whitening noise in a signal received by a receiving device from a transmitting device via a multi input multi output (MIMO) communication channel, a data unit is received at the receiving device via the MIMO communication channel. A channel estimate H corresponding to the MIMO communication channel is determined based on the training signals. A noise scaling factor s is determined. The noise scaling factor s is a ratio of variance of noise at the receiving device to a variance of noise at the transmitting device. A noise whitening matrix W is determined using the channel estimate H and the noise scaling factor s. The noise whitening matrix W is applied to (i) the channel estimate H to generate an effective channel matrix Heff and (ii) to the data symbols to generate whitened data symbols.

Claims22

Dependent claims

A method of whitening noise in a signal received by a receiving device from a transmitting device via a multi input multi output (MIMO) communication channel, the method comprising:

receiving, at the receiving device, data from a data unit via the MIMO communication channel, wherein the data includes at least training symbols and data symbols;
determining, with the receiving device and based on the training symbols, a channel estimate H corresponding to the MIMO communication channel;
determining a noise scaling factor s, wherein the noise scaling factor s is a ratio of variance of noise at the receiving device to a variance of noise at the transmitting device;
determining, using the channel estimate H and the noise scaling factor s, a noise whitening matrix W;
and
applying the noise whitening matrix W to (i) the channel estimate H to generate an effective channel matrix Heff and (ii) to the data symbols to generate whitened data symbols.

3 more elements

An apparatus, comprising:

a network interface configured to receive data from a data unit via a MIMO communication channel, wherein the data includes at least training symbols and data symbols,
wherein the network interface includes:
a channel estimation unit configured to determine, based on the training symbols, a channel estimate H corresponding to the MIMO communication channel;
a noise scaling factor generator configured to determine a noise scaling factor s, wherein the noise scaling factor s is a ratio of variance of receiver noise to a variance of transmitter noise, and
a noise whitening unit configured to determine, using the channel estimate H and the noise scaling factor s, a noise whitening matrix W, and
wherein the network interface is further configured to apply the noise whitening matrix W to (i) the channel estimate H to generate an effective channel matrix Heff and (ii) the data symbols to generate whitened data symbols.

3 more elements

Dependencies are inferred from the claim text.

Noise whitening in a WLAN receiver

Life of this patent

Noise whitening in a WLAN receiver

Life of this patent

Abstract

Claims22