PARTIAL FFT PROCESSING AND DEMODULATION FOR A SYSTEM WITH MULTIPLE SUBCARRIERS

摘要

Techniques for efficiently performing partial FFT for subcarriers of interest are described. The N total subcarriers may be arranged into M sets. Each set may contain K subcarriers uniformly distributed across the N total subcarriers, where . For the partial FFT, pre-processing is initially performed on time-domain samples to obtain intermediate samples. The pre-processing may include performing M-point FFTs on the time-domain samples and multiplying the FFT outputs with unit complex values. For each set of subcarriers of interest, a K-point FFT is performed on a set of intermediate samples to obtain a set of frequency-domain symbols for that set of subcarriers. Since K is typically much smaller than N, substantial savings in computation and power may be realized when only one or few sets of subcarriers are of interest.