Patent ID: 8149902

Claim:
A method of relaxing the IP2 (2nd order intercept point) requirements for an 802.11a/g or a WiMAX wireless receiver of a transceiver having RF I and Q signal paths that need to work in an environment with strong jamming signals, the wireless receiver having a local oscillator having an uncorrected local oscillator frequency that differs from the carrier frequency of a received signal by a percentage of a subcarrier frequency spacing, comprising: correcting the uncorrected local oscillator frequency of the wireless receiver by fractionally changing a synthesizer frequency and not adjusting a reference clock frequency so that the difference in the frequency of the carrier frequency of a received RF signal and the corrected local oscillator frequency of the wireless receiver to a down shifting mixer is at a difference frequency that is 3% or less than the subcarrier spacing; determining and subtracting respective DC levels of each of the respective signals in the I and Q signal paths over a period of a fast Fourier transform time window for every symbol; taking a fast Fourier transform of the signals in each of the I and Q signal paths over the fast Fourier transform time window after the respective DC level has been subtracted; transmitting signals from the I and Q signal paths of the transceiver without changing the local oscillator frequency from the corrected local oscillator frequency, interpolating in the time domain the I(t) and Q(t) samples of the signals to be transmitted so that the correct I(t) and Q(t) are transmitted by the wireless transceiver.