EXIT Chart Aided Design Of Turbo Codes For Two-Way Relay Network

The relay and cooperative techniques have attracted extensive attentions in the wireless communications due to the extra space diversity gain. The application of the physical network coding in relay networks can effectively improve the transmission rate and the throughput.Wireless Two-Way relay channel can be looked upon as an important component unit of the wireless multi-hop network. Due to the near Shannon limit performance, Turbo Code can be applied to improve the systematic performance of the relay cooperative communication system. Therefore, this paper focuses on a joint design of Turbo code and physical network coding for the wireless Two-Way relay channel. The optimization of the proposed scheme is also studied in detail.In this thesis, a low complexity two-user turbo decoding scheme for Two-Way relay network is proposed. On the relay node, two same Turbo codes from the two source nodes are converted to a new equivalent parallel concatenated code via simplified sum trellis. Therefore, the network coding information can be obtained directly by a parallel turbo decoder.In order to obtain better systematic performance, the Turbo codes of the source nodes must be selected properly. In this issue, we employ the analysis method of EXIT chart to the simplified sum trellis decoder, and then find out a series disciplines of performance to the turbo codes of the source node. Accordingly, we evolve several criterions of choosing codes. The performance can be improved either by adding the number of the register or by using primitive polynomial codes.