코드집합 분할 방식의 확장 m-시퀀스 기반 정진폭 멀티코드 대역확산 통신 시스템을 위한 개선된 패리티 검사 기반 수신기에 관한 연구

The multi-code spread spectrum communication system, which spreads data bit stream by multiplexing orthogonal codes,can transmit data in high rate. However it needs the high-cost good linear amplifier because of the multi-level output signal. In order to overcome this drawback several systems making the amplitude of output signal constant with Walsh codes have been proposed. Recently constant amplitude pre-coded multi-code spread spectrum systems using extended m-sequence have been proposed. In this paper we consider an extended m-sequence based constant amplitude multi-code spread spectrum system with code set partitioning. By grouping the orthogonal codes into 4 subsets, not only is the computational complexity of the transceiver reduced but BER performance also improves. It has been shown that parity checking on four detected codes at the receiver can correct code detection error and result in BER performance enhancement. In this paper we propose a improved parity check receiver. We carried out computer simulation to verify feasibility of the proposed algorithm.