An improved DDCSK-walsh coding technique with BCJR decoding

Based on Walsh Codes (WC), a chaotic multi-access transmitting system, called differentially differential chaos shift keying (DDCSK) multi-access (DDCSK-WC), has been proposed recently. The DDCSK-WC enhances error performance and robustness against inter-symbol-interference in a multi-path fading channel compared to the conventional DCSK-WC system. As for the demodulation of DDCSK-WC, this paper presents an improved detector at the receiver by adopting Bahl, Cocke, Jelinek, and Raviv (BCJR) decoding algorithm. We show that the proposed BCJR detector can obtain a performance gain about 2 dB over the convention detector used in DDCSK-WC, while retaining its hardware complexity almost unchanged. The theoretical and simulated noise performances of the proposed system demonstrate their high consistence.