Patent ID: 8386552
Filing Date: 2013-02-26
Classification: G06F

Abstract:
1. In a data processing system having a twiddle factor unit, a method for performing a mixed-radix discrete Fourier transform (DFT) having a block size, N, and a maximum block size, Nmax, wherein the maximum block size includes a radix that is not a power of 2, the method comprising: receiving a delta value at an input of the twiddle factor unit, the delta value representing a ratio of a modified maximum block size to the block size, wherein the modified maximum block size is a power of 2; using the delta value to obtain a step size for generating indices of a look-up table stored within the twiddle factor unit, wherein the look-up table stores real and imaginary components of twiddle factors corresponding to a set of block sizes of the DFT; wherein the look-up table includes a precoded communication signal based on the twiddle factors; and in response to each generated index, outputting from the look-up table, a real and imaginary component of the twiddle factor corresponding to the DFT having the block size N, and providing the precoded communication signal for an up-link transmission to a base station.