Patent ID: 7720162

Claim:
An apparatus comprising: at least one processor configured to select at least one set of subcarriers from among all sets of subcarriers where the at least one set is less than the all sets, to perform pre-processing on time-domain samples to obtain intermediate samples wherein the intermediate samples are defined by y m ⁡ ( n ) = ∑ i = 0 M - 1 ⁢ ⁢ x ⁡ ( n + K · i ) · W N m ⁡ ( n + K · i ) , for ⁢ ⁢ n = 0 , … ⁢ , K - 1 , with x representing the time-domain samples, m representing the at least one set of subcarriers, M representing the all sets, K representing a quantity of the intermediate samples and W is a phasor that rotates around a unit circle, and to perform at least one fast Fourier transform (FFT) on the intermediate samples to obtain frequency-domain symbols for the at least one set of subcarriers; and a memory coupled to the at least one processor; wherein the memory is configured to store the time-domain samples in a first direction, and to provide the time-domain samples for pre-processing in a second direction and further wherein the first direction is column-wise and the second direction is row-wise.