非标准参数的CCSDS Turbo码译码器性能仿真

实现了一款具有通用性的Turbo码编译码器,对CCSDS(Consultative Committee for Space Data Systems)规范中的信息数据帧长度进行扩展,不仅支持原有的5种帧长,而且能实现16384bit内255bit的任意整数倍帧长的信息序列的编译码.针对标准外的编码参数,分别对不同译码算法(MAP,SW-MAP,log-MAP算法)的译码性能进行了仿真,并与标准参数的译码器进行比较.将算法程序以C++动态链接库的形式实现,编写Python测试程序,产生待仿真码长的随机信号,编译码后计算误码率,绘制出信噪比和误码率的关系曲线图.通过相应的仿真发现,所设计的编译码器具有所需的通用性;同时对不同算法的性能进行了分析比较;研究各项参数对于译码性能的影响,包括信息序列长度、码率、迭代次数等.

Simulation of universal CCSDS Turbo-codes decoder of non-standard parameters

A universal Turbo-codes decoder was designed, which not only covers the parameters suggested by consultative committee for space data systems (CCSDS), but also supports other frame length (an integral multiple of 255bit) within 16384bit. Standard and non-standard frame lengths, as comparisons, were both simulated on three decoding algorithms, including MAP, SW-MAP and log-MAP. The algorithms were realized in the form of C++ dynamic link library. Python test program was written to generate random signal of needed length and call the DLL mentioned above for encoding and decoding. The graphs about the relation between signal noise ratio and bit error rate were drawn after data calculation. By simulation, the decoder designed was proved universal. In addition, performance of different algorithms were compared and analyzed. Simulations were done to study the relations between decoding performance and some key parameters, including frame length, bit rate, the number of iterations and so on.