An efficient systolic array for the discrete cosine transform based on prime-factor decomposition

Abstract

A new design of a systolic array for computing the discrete cosine transform (DCT) based on prime-factor decomposition is presented. The basic principle of the proposed systolic array is that one-dimensional (1-D) DCT can be decomposed to a 2-dimensional (2-D) DCT by input and output index mappings and the 2-D DCT is computed efficiently on a 2-D systolic array. We modify Lee's input index mapping method in order to construct one input mapping table instead of three input index mapping tables. The proposed systolic array avoids the need for the array transposer that was required by earlier implementations for the prime-factor DCT algorithms, and thus all processing can be pipelined. The proposed design of systolic array provides a simple and regular structure, which is well suited for VLSI implementation.