Patent ID: 8050173

Claim:
A fast Fourier transform (FFT) apparatus for use in an orthogonal frequency division multiplexing (OFDM) receiver that has a dynamic signal-to-noise ratio (SNR) requirement, the OFDM receiver for receiving an OFDM signal comprising a plurality of sub-carriers, the FFT apparatus comprising: a datapath configured to compute an FFT over a block of data samples that are obtained from the received OFDM signal; and a control unit configured to adjust a precision with which the datapath computes the FFT over the block of data samples based on the dynamic SNR requirement of the OFDM receiver, wherein the control unit is configured to adjust the precision by directing the datapath to ignore least significant bits of data the datapath operates on, wherein the dynamic SNR requirement of the OFDM receiver is determined based on a number of bits transmitted per symbol over at least one of the plurality of sub-carriers in the received OFDM signal.