Implementation of Low Power and Small Area 128-Point Mixed Radix 4-2 FFT Processor for OFDM Applications
Discrete Fourier Transform (DFT) is a very important technique used in modern Digital Signal Processing (DSP) and Telecommunications, especially for the applications involving Orthogonal Frequency Division Multiplexing (OFDM) systems. The Fast Fourier Transform (FFT) is an efficient algorithm used to compute the DFT and its inverse. In OFDM, the Inverse Fast Fourier transform (IFFT) is required to produce multiple subcarriers. The authors' paper involves the implementation of a 128-point pipeline FFT/IFFT processor for OFDM applications using Mixed Radix 4-2 FFT algorithm and R2MDC style. The proposed architecture comprises one parallel-to-parallel (i.e., if all available input data are in parallel, then all output data are generated in parallel) 128-point FFT computation in less than 312ns thereby meeting the standard specifications.