分组差错控制在系统删除信道上的性能与优化

软判决译码是提高差错控制系统性能的一种有效方法,但软判决译码器比二元译码器需要更复杂的硬件和更多的时间。当解调器的输出量化为三个电平时,可以使用同时纠正错误和删除的译码器,该译码器和二元译码器的复杂性差不多。本文采用二元PSK调制和相干解调,用限距离的分组译码器进行前向错误纠正。假设信道是加性高斯白噪声信道,具有功率谱密度No,本文导出了系统误字率的计算公式。借助于最优化算法,详细地研究了系统的最佳设计问题。以Golay码和BCH码为例,对系统的性能进行了大量的计算,并给出了系统的最佳设计曲线。

Performance and Optimization of Block Error Control Systems on Erasure Channels

The soft decision decoding is an efficient method for improving the performance of error control systems.However, soft decision decoders require more complicated hardward and more time than binary decoders. When the output of a demodulator is quantized into three levels, error and erasure correcting decoders may be used, which have nearly the same complexity as binary decoders. In this paper binary PSK modulation and coherent demodulation are adopted, and block decoders with bounded distance are used for the forword error control. The formula o,f error word probabilities is inferred on additive Gaussian white noise channels with single side power spectrum density No. With the help of the algorithm of optimization, the problem of optimum design is dealt with in detail. The performance and the optimum design curves of the systems using the Golay code and the BCH codes are gived.