이동 통신 채널에서 다중 트렐리스 부호화된 $\pi$/4 shift QPSK의 연집 에러 정정 복호 방식

A burst-error-correcting decoding scheme of multiple trellis-coded $\pi$/4 shift QPSK for mobile communication channels

In this paper, the dual-mode burst-error-correcting decoding algorithm is adapted to the multiple trellis-coded .pi./4 shift QPSK in order to achieve the improvement of bit error rate (BER) performance over fading channels. The dual-mode adaptive decoder which combines maximum likelihood decoding with a burst detection scheme usually operates as a Viterbi decoder and switches to time diversity error recovery whenever an uncorrectable error pattern is identified. Rayleigh fading channels and Rician fading channels having the Rician parameter K=5dB are used in computer simulation, and the simulation results are compared with those of interleaving techniques. It is shown that under the constraint of the fixed overall memory quantity, the dual-mode adaptive decoding scheme gains an advantage in the BER performance with respect to interleaving strategies.