| Cooperative diversity was proposed by Andrew Sendonaris, while J. N. Laneman and T. E. Hunter put forward a comparatively ideal cooperative communication network as well as relaying protocol. They had built up a rounded cooperative communication system. J. N. Laneman did more research on the cooperative communication system and divided relaying protocol into fixed relaying protocol, selective relaying protocol and incremental relaying protocol according to the signal processing of the relays. At the same time, T. E. Hunter s major contribution was proposing coded cooperation. It is more flexible and can choose channel code according to the channel conditions and other factors. Furthermore, it can adjust transmission speed as need. Channel coding and network coding are increasingly maturation. So it is promising to apply channel coding and network coding into cooperative communication network. Therefore, coded cooperation based on Low Density Parity Code (LDPC) and network code was studied deeply in this thesis.In the thesis, the basic relaying model and relaying protocol was studied, including Amplify-and-Forward, Decoded-and-Forward, incremental relaying and coded cooperation, and analysis the merits and demerits of the protocols.Then coded cooperation based on LDPC was studied deeply. The traditional coded cooperation has the problem of low error correcting capability. And a novel coded cooperation based on LDPC, which has strong correction capability, was proposed. The performance analysis and simulation results show that the novel coded cooperation can improve system capacity and reduce outage probability.At last, considering the performance of coded cooperation based on LDPC under unsymmetrical channel and find out that performance of the better one will be influenced. Hence it is good to combine network code into coded cooperation based on LDPC. And the simulation results show that this method solves the existing problem so well and improve the whole performance of the system. |
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