基于EXIT图的串行级联连续相位调制的外码设计

The Outer Code Design of Serially Concatenated Continuous Phase Modulation Based on EXIT Chart

串行级联连续相位调制(SCCPM)系统可以大大地提高系统的功率利用率,这使得它在无线通信领域中得到广泛应用。给出了基于外信息传输(EXIT)图的SCCPM系统的收敛性能分析及外码设计,在CPM参数给定的情况下,通过EX IT图可以找出与该调制最匹配的外码。仿真结果表明:对于同一种调制不同外码的SCCPM系统,收敛的门限不同;收敛的门限越低,性能越好。

Serially concatenated continuous phase modulation（SCCPM） can greatly improve the power efficiency of the system,so it is widely used in wireless communications.A convergence analysis and the outer code design of SCCPM system are presented,based on the extrinsic information transfer（EXIT） chart.When the parameter of CPM is given,the best matched outer code can be found by the EXIT chart.The simulation results show that the convergence thresholds of the SCCPM with the same modulation and different outer code are different,and the lower the threshold,the better the performance.