Circuit-sharing design between FFT and IMDCT with pipeline structure for DAB receiver

Abstract

In this paper, a "Circuit-sharing scheme" is proposed to design a reduced chipset for DAB (digital audio broadcasting) receiver, involved the fast Fourier transform (FFT) circuit in the orthogonal frequency division multiplexing (OFDM) and IMDCT (inverse modified discrete cosine transform) synthesis filter in the audio decoder Comparing to the existent method, it can achieve a highly integrated, low power and small size DAB receiver. We implement the IMDCT synthesis filter of MPEG audio decoder and the 2048-point complex FFT by a single processing element with pipeline structure. Simulations demonstrate that the proposed circuit sharing can reduce the chipset area and meet the specification of DAB. The gate count is about 6692 excluding the 2048/spl times/16 RAM and 512/spl times/32 ROM.