Improved algorithm for joint detection and decoding on the joint sparse graph for CDMA systems

Аннотация

Joint sparse graph for code division multiple access systems (JSG-CDMA) combines multiple accessing (lowdensity signature) and forward error correction (low-density parity check code) techniques, and it achieves satisfactory performance under overloaded conditions. In this study, the authors carry on the research on the joint detection and decoding for JSG-CDMA, and analyse the syndrome effect of message passing on the JSG by the extrinsic information transfer (EXIT) chart. An improved algorithm for joint detection and decoding on the JSG-CDMA receiver is proposed,and the convergence behaviour of the algorithm is analysed by EXIT chart. Simulation results show that improved algorithm enhance the system performance significantly with a marginal increase of the computational complexity.