An efficient CORDIC array structure for the implementation of discrete cosine transform

Abstract

We propose a novel implementation of the discrete cosine transform (DCT) and the inverse DCT (IDCT) algorithms using a CORDIC (coordinate rotation digital computer)-based systolic processor array structure. First, we reformulate an N-point DCT or IDCT algorithm into a rotation formulation which makes it suitable for CORDIC processor implementation. We then propose to use a pipelined CORDIC processor as the basic building block to construct l-D and 2-D systolic-type processor arrays to speed up the DCT and IDCT computation. Due to the proposed novel rotation formulation, we achieve 100% processor utilization in both 1-D and 2-D configurations. Furthermore, we show that for the 2-D configurations, the same data processing throughput rate ran be maintained as long as the processor array dimensions are increased linearly with N. Neither the algorithm formulation or the array configuration need to be modified. Hence, the proposed parallel architecture is scalable to the problem size. These desirable features make this novel implementation compare favorably to previously proposed DCT implementations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>