基于LDPC编码的混合转发协作模型

为有效解决LDPC编码在中继协作系统应用中存在的问题,提出基于LDPC编码的混合转发协作模型(HF-LDPC).根据放大转发(AF)和译码转发(DF)特点,当信道不好时,中继采用译码放大转发模式；而当中继完全正确译码时,中继切换到译码转发模式.同时充分发挥LDPC码字内码元间固有的相关性,通过不同的用户发送码字的不同部分,采用LDPC和-积译码算法,方案可获得分集增益和编码增益.仿真结果表明:基于LDPC 编码的混合转发协作模型性能优于其他协作模型,具有较好性能.

Hybrid-and-forward cooperative model based on LDPC coding

In order to solve the problems of LDPC codes application in relay cooperative system effectively,the hybrid and forward cooperative model based on LDPC codes was proposed.According to amplification forwarding(AF) and decode forward(DF) characteristics,when the channel state is bad,the relay uses decode amplification forward mode;and when the relay correctly decodes completely,the relay switches to decode forward mode.Moreover,extending the coherence among the symbols of the LDPC code words,sending different parts of them by different users,and using LDPC sum product decode algorithm,the scheme can obtain diversity gain and coding gain.Simulation results show that performance of LDPC codes cooperative model based on the hybrid-and-forward is superior to other model.