Texas Instruments Corporation

Louis G Johnson

Toshiaki Yoshino

Yiwan Wong

A pipelined Fast Fourier Transform (FFT) architecture includes a memory for storing complex number data. A pipelined data path is coupled to the memory for accessing R complex number data therefrom, for computing an FFT butterfly, and storing R results from the FFT butterfly computation in the memory during one pipeline cycle.

Pipelined Fast Fourier Transform (FFT) architecture

A method for densely packing a complex multiplier for multiplying two complex numbers in the form of (A+jB) and (X+jY) is provided. The complex multiplier consist of two multipliers which perform (A*X), (A*Y), (B*X) and (B*Y) multiplications, and each multiplier has a plurality of partial product generating stages and a partial product summing stage. The method comprises interleaving the plurality of partial product generating stages of the (A*Y) multiplier between the plurality of partial product generating stages of the (A*X) multiplier, forming the partial product summing stage adjacent the interleaved partial product generating stages of the (A*X) and (A*Y) multipliers. Further interleave the plurality of partial product generating stages of the (B*Y) multiplier between the plurality of partial product generating stages of the (B*X) multiplier, and form the partial product summing stage adjacent the interleaved partial product gneerating stages of the (B*X) and (B*Y) multipliers.

Method for densely packing a complex multiplier

Apparatus for generating memory addresses for accessing and storing data in an FFT (Fast Fourier Transform) computation is provided. The FFT computation is typically performed by computing a plurality of FFT butterflies belonging to a plurality of ranks. The apparatus includes a butterfly counter for determining the current FFT butterfly being computed. The butterfly counter produces a plurality of butterfly carries. A rank counter for determining the rank of said current FFT butterfly being computed produces a rank number. Coupled to the rank and butterfly counters is incremental curcuitry, which generates an incremental number in response to the rank number and the butterfly carries. An adder circuitry coupled to the incremental circuitry adds the incremental number and a plurality of memory addresses to produce the FFT data memory addresses.

Growing community of inventors

Dallas, TX, United States of America

Louis G Johnson