Robust L_p-Norm Decoding for BICM-Based Secondary User Systems

摘要

The frequency bands used by secondary user systems such as cognitive radio and ultra—wideband (UWB) systems are subject to various forms of non—Gaussian noise and interference including co—channel and narrowband interference caused by the primary user and other secondary users as well as man—made impulsive noise. For secondary user systems employing popular bit—interleaved coded modulation (BICM) we propose a robust L_p—norm metric for Viterbi decoding to overcome the harmful effects of non—Gaussian noise and interference. For the resulting system, we derive an approximate upper bound on the bit error rate (BER) and a general analytical expression for the asymptotic BER valid for all practically relevant types of fading, including Rayleigh, Ricean, Nakagami—m, Nakagami—q, and Weibull fading, and all types of noise and interference with finite moments. Simulation and analytical results show that, in non—Gaussian noise and interference, the proposed L_p—norm metric yields large performance gains over the conventional L_2—norm metric and outperforms erasure decoding.