一种基于复数域网络编码的双层卫星通信系统

Double-layer Satellite Communication System Based on Complex Field Network Coding

针对卫星通信网络吞吐量不足、可靠性不高的问题,提出一种基于复数域网络编码(Complex Field Network Coding,CFNC)的卫星通信方案。该方案在信号发送前对源信息作预编码处理,即在复数域上选取一个大小合适的参数化空时码与源信号相乘,编码后的信号与源信号在复数域上有着一一映射关系。对该方案的吞吐量和成对差错概率(Pairwise Error Probability,PEP)做了详尽的理论分析,结果表明,采用该编码方案的卫星通信系统在终端发射功率不变的情况下,吞吐量比路由模式提高了100%以上,比传统的CFNC方式至少可提高75%。该方案还可以扩展至更多的地面源节点,从而支持多用户网络通信。最后,仿真实验表明,在较高的信噪比下,PEP仿真值逼近于渐近值,验证了理论分析的正确性。

In order to improve the throughput and reliability of satellite network, we proposed a satellite communication scheme based on complex field network coding （CFNC）. In the scheme, the original message is pre-encoded before transmission. Specifically,it is multiplied by a coding mtrix of parameter space-time codes over complex field. There exi- sts a bijeetion mapping between the encoded signals and the original ones. Detailed analysis to the performance of throughput and pairwise error probability （PEP） are implemented. The experimental results prove that when the trans- mission power is kept constant, the throughput of our scheme is 100% higher than routing and 75% higher than pre- vious complex field network coding scheme. Furthermore, the scheme can also be extended to multbuser network com- munications with more ground stations. Simulation experiments show that PEP approaches the asymptotic curves at high SNR. This supports the theoretical analysis of PEP.