卫星通信中基于DSP的Viterbi算法的实现

在卫星通信系统中，卷积编码可以纠随机错误，实现差错控制，其译码芯片Q1900早已停产，从而转向采用其他手段实现Viterbi算法。用TMS320C54X系列芯片实现了Viterbi译码算法，介绍了软件实现的几个关键步骤，采用加-比-选方式，并利用大数判决准则，简化算法实现，同时，对算法进行了计算机仿真。根据实现情况计算其所需要的指令和时间，可完成多路译码。该方法已在实际工程中得到具体应用，系统运行稳定可靠。

Realization of Viterbi Decoding Algorithm Based on DSP in Satellite Communication

Convolutional coding is an efficient system for reliable satellite communication, which can detect random errors and realize error control. But its Q1900 decoding chip has stopped production long ago, so one has to realize Viterbi algorithm with other methods. This paper proposes to realize convolutional decoding algorithm with TMS320C54X. It explains in detail several key steps in software, such as adopting add-compare-select method, maximum decision rule and simplified arithmetic. At the same time, with computer simulation the number of instructions and required time in the practical condition are computed. Thus, multi-road decoding are carried out. This method is applied in a practical project, which showed good stability and reliability.