The nonredundant error correction differential detection in soft-decision decoding

Abstract

This paper proposes the application of nonredundant error correction (NEC) in soft-decision decoding. Combined with differential demodulation of /spl pi//4DQPSK, we emphasize the analysis of the new algorithm. A practical implementation scheme is presented. The BER performance and correction capability of NEC is investigated by computer simulation in AWGN and Rician fading channels. The simulation results show that the performance improvement of the proposed algorithm is superior to conventional differential demodulation by 1.4 dB at a BER of 10/sup -4/ in the AWGN channel. In the Rician channel there is the same notable performance improvement. The algorithm makes NEC able to be used in soft-decision decoding, which is widely applied in practical satellite communication systems. It overcomes the limitation that NEC could only be used in hard-decision systems. Therefore, the system capacity and communication quality is notably improved. It is worthwhile for satellite communication for which power and spectrum are limited.