FPGA implementation of unified kernel structure for MDCT/IMDCT in audio coding schemes

Abstract

The modified discrete cosine transform (MDCT) and inverse MDCT (IMDCT) are two of the most computationally intensive operations in layer III of MPEG audio coding standard. In this paper, we present an efficient fast unified kernel structure and FPGA implementation for forward and inverse MDCT algorithm based on radix-3 algorithm of a sequence with length-3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sup> . We implemented an efficient MDCT IP core capable of both forward and inverse 36-point MDCT computation. It was found that the computation is faster than in well known FPGA implementations. The proposed core is suitable for the very high performance demanding digital audio compression and modern mobile applications.