3-D Turbo Codes For Cooperative Relaying Schemes

Cooperative communication system has been considered as one of the premising techniques in the 4G communication system, with its excellent characteristics of improving the channel capacity and combating multi-path fading. How to improve its decoding performance at the destination is still a problem for us to study. 3-D Turbo codes becomes a new research direction for this problem, as its considerable performance in the error floor region. In this paper cooperative relaying schemes based on 3-D Turbo codes are studied to improve the performance of cooperative communication system.First, cooperative diversity and network coding based on relaying technologies are introduced briefly. Then the basic principles of traditional turbo code and 3-D turbo code are presented, and simulation results and analysis of 3-D turbo code are given in detail.Second, for the relay cooperative communication system, a new joint network-channel coding scheme based on 3-D turbo codes is proposed. The network coding method at the relay node and corresponding decoding structure at the destination are discussed in detail. Simulation results show that the proposed scheme could obtain 2d B gain compared with distributed 3-D turbo codes when the SNR is very low, and the gain will increase as the SNR become higher.Finally, for the multiple access system, a hierarchical modulation method based on 3-D turbo codes for cooperative relaying is presented. The corresponding information processing methods of source node, relay node, and the destination node are discussed in detail. Simulation results show that the proposed scheme could get a considerable performance with no complexity increasing.