Cooperative Relaying Schemes Based On3-D Turbo Codes

Multiple access relay network (MARN) is one of the basic models in wirelesscommunication networks. In order to improve the decoding performance at thedestination of the MARN, distributed coding schemes for cooperative relaying arestudied. As3-D Turbo codes have considerable performance in high SNR region, ourschemes are mainly based on3-D Turbo codes.First, the encoding and decoding principles of traditional Turbo codes areintroduced. Then we focus on3-D Turbo codes. Based on the simplified Monte Carolalgorithm, we analyze the EXIT Charts of3-D Turbo codes, and get the reasons that3-D Turbo codes could get a performance.Second, for the multiple access system with one source, one relay and onedestination, a cooperative relaying scheme based on the3-D Turbo code is proposed.The encoding structures at the source node and relay node, and the correspondingdecoder structure at the destination node are given in detail. Simulation results showthat the proposed scheme could obtain about2dB gain compared with the distributedTurbo coding scheme when the SNR is very low.Finally, we apply3-D Turbo coding based cooperative relaying to the multipleaccess system with one source, multiple relays and one destination. The encoderstructure of the system and the corresponding decoder structure are discussed detailly.Moreover, in order to improve the relaying efficiency, another distributed3-D Turbocoding with selective relaying is proposed. Simulation results show that this proposedscheme could get a considerable performance in low SNR region.