移动数字信道差错控制系统性能估计与计算机模拟

Performance Estimation and Computer Simulation of Error Control System in the Digital Mobile Communication Channel

本文以三状态Markov模型作为移动信道长突发误码的概率模型,由Markov模型参数和差错统计量间的关系分析了移动信道的长突发误码特征,研究了信道错误分布概率p(n,m),对在交错与非交错两种不同情况下的BCH分组码的纠错性能进行估计。在对交错的BCH码的性能估计中,提出用BSC信道参数对移动信道的纠错性能进行近似估计的方法,随后,采用简化的模拟方法,并利用模型参数产生的移动信道差错序列,对几组不同码长、不同编码效率的BCH码进行了交错与非交错下的计算机模拟试验。理论估计与计算机模拟结果取得了令人满意的一致性。结果表明:在移动信道长突发干扰下采用交错编码方案可获得三个数量级的性能改善,对实施交错编码的移动信道,当交错度足够大时用BSC模型来估计纠错性能比较简便、实用,在工程上具有一定的实际意义。

In this paper, the Markov model with three states is used for the probability model in the digital mobile communication channel with long burst error. The characterization of long burst error and the error distribution probability p (n,m) for the mobile channel are calculated by the relation between the parameters of the model and the error statistical parameters. The performance of interleaved and no interleaved BCH codes is estimated. The method is proposed that the performance of interleaved BCH codes is estimated by use of the parameters of BSC channel. And then, a few of interleaved BCH codes with different code length and different code rate are simulated by means of a simplified simulation method. The theoretical estimation is very close to the result from simulation by a computer. The result show that a considerable improvement on performance by three orders of magnitude is obtained from interleaving scheme and it is very simple and practical to estimate the performance of error-correcting of interleaved BCH codes by use of BSC channel when the interleaving degree is large enough.