Patent ID: 8676144

Claim:
A method comprising: at a wireless device, analyzing energy received at a plurality of antennas in an unlicensed frequency band performed to detect interference in the unlicensed frequency band during first time intervals between reception of desired signals at the wireless device; determining the type of interference detected in the received energy during the first time intervals; generating parameters for a spatial nulling filter including a finite impulse response (FIR) filter based on the type of interference detected in the received energy during the first time intervals, wherein the generating comprises: generating FIR filter coefficients for the FIR filter, the FIR filter including multiple FIR filter blocks, one block for each antenna, and each block comprising multiple FIR filter sub-blocks, respective received signals obtained at the plurality of antennas to be supplied to a corresponding input of the multiple FIR filter sub-blocks in each filter block, and wherein outputs of the FIR filter sub-blocks in each filter block are added by a corresponding summer to produce a filtered signal from each filter block; supplying the parameters, including the FIR filter coefficients, to the FIR filter of the nulling filter prior to a second time interval when the desired signals are to be received; and during the second time interval, applying in the time domain the FIR filter of the nulling filter to signals obtained from energy received at the plurality of antennas during the second time interval.