FFT computation with linear processor arrays using a data-driven control scheme

Abstract

For a large numberN of data points, linear FFT arrays consisting of ?(log2N) processors provide significant economy in hardware. In this paper we discuss the radix-2 decimation-in-frequency Cooley-Tukey algorithm implemented on linear arrays, thereby allowing a continuous real-time application using a word-serial input data stream to the linear arrays. In order to avoid memory access and data path switching under central control, we present a novel data-driven scheme permitting the proposed linear arrays to correctly operate on arbitrarily arriving signal sequences. This distributed control scheme incorporates a control signal propagated with the data signals, in the form of a tag attached to data items. The tag provides control information to initiate the access to the memory containing the coefficients and to select and appropriate data path so that regular data flow can be achieved within the linear array. The cascade structures are well suited for the computation and can operate in pipeline fashion at extremely high data rates. The proposed data-driven control scheme can be used with both synchronous and asynchronous (wavefront) processor arrays.