基于BICM-ID的多址接入协同中继系统的性能研究

为了提高联合网络编码调制在多址接入中继系统的上行链路衰落信道下的性能，提出了在中继节点处使用卷积码与16进制正交幅度调制改进集分割映射星座映射方式相匹配的联合编码调制方式，并在基站处设计了相应的迭代译码解调方案。通过衰落信道下系统误比特率的性能渐近限和外信息转移图的分析，证明了在衰落信道下，改进集分割映射在卷积码迭代译码方案下优于传统格雷映射方式。软件仿真结果也证明了在瑞利衰落信道下，改进集分割映射相对于传统格雷映射方法在误码率为10^-5时获得了4 dB的显著性能增益。

Performance analysis of BICM-ID based multiple access relay cooperative systems

To improve the performance of the cooperative network coding modulation in the uplink multiple access relay systems under Rayleigh fading channels, a modified set partitioning (MSP) mapping to match with the convolutional encoding at relay stations is proposed, and a corresponding iterative decoding scheme at base stations is designed. Based on the asymptotic bound of bit error probability over Rayleigh fading channels and extrinsic information transfer (EXIT) chart analysis, two different 16-QAM mapping schemes are compared, and it is proved that MSP mapping is optimal for the proposed scheme. The simulation results also show that the proposed scheme obtains a 4 dB gain by introducing MSP mapping over Rayleigh fading channels.