Combined Iterative Demapping and Decoding for Coded MBOK DS-UWB Systems

摘要

This paper presents a novel decoding strategy called combined iterative demapping/decoding (CIDD), for coded M-ary biorthogonal keying-based direct sequence ultra-wideband (MBOK DS-UWB) systems. A coded MBOK DS-UWB system consists of a convolutional encoder, an interleaver, and an MBOK DS-UWB pulse mapper. CIDD improves the error rate performance of MBOK DS-UWB systems by applying the turbo principle to the demapping and decoding processes at the receiver side. To develop the CIDD, a soft-in/soft-out MBOK demapping algorithm, based on the max-log-MAP algorithm, was derived. Simulation results showed that using CIDD siginificantly improved the error rate performance of both static and multipath fading channels. It was also shown that the computational complexity of CIDD is comparable to that of the Viterbi decoding used in [133,171]_8 conventional convolutional coding.