Constant geometry split radix FFT

摘要

An apparatus for performing a Fast Fourier Transform (FFT) is provided. The apparatus comprises a reorder matrix, symmetrical butterflies, and a memory. The reorder matrix is configured to have a constant geometry, and the butterflies are coupled in parallel to the reorder matrix. The memory is also coupled to the reorder matrix and each butterfly. The reorder matrix, the butterflies, and the memory can then execute a split radix algorithm.

主权项

1. An apparatus comprising:
a first datapath that generates real and imaginary portions of a first output signal, wherein the first datapath includes:
a first summing circuit that receives real portions of a first signal and a second signal; anda second summing circuit that receives imaginary portions of the first and second signals; and a second datapath that generates real and imaginary portions of a second output signal, wherein the second datapath includes:
a third summing circuit that receives the real portions of the first and second signals;a multiplexer that is configured to select between the imaginary portion of the first signal and an inverse of the imaginary portion of the first signal based on a control signal; anda fourth summing circuit that receives the imaginary portion of the second signal and that is coupled to an output of the multiplexer, wherein the control signal selects at least one of a first operation and a second operation for the fourth summing circuit; andan output circuit that is coupled to third summing circuit and the fourth summing circuit and that is controlled by the control signal.