一种基于信道信息修正的解码后合并算法

A Modified Combining-after-Decoding Algorithm Based on Channel State Information

远距离短波通信过程复杂,接收信号相位、幅度都发生剧烈变化。为提高远距离短波通信性能,采用本土多台站构成宏分集,结合最大比合并方法性能最优和解码后合并方法实现简单的优点,对两种方法进行折衷,提出了一种基于信道信息修正的解码后合并方法,并对其性能进行理论分析和仿真实现。仿真结果表明,在误码率为10-4时,修正后的解码后合并法比传统择多判决的方法提高了2 dB,当接收台站数大于5时,该修正算法性能优于等增益法接近最大比法。该方法易于实现,为实际通信中合并方法的选择提供了有效参考。

The process of long- distance HF communication is complex, and the received signal＇s amplitude and phase change dramatically. To improve the performance of long - distance HF communication, the local stations are used to form macro diversity. The method of maximum ratio combining has optimal performance and the method of combining after decoding is simple. Compromising the advantages between the two methods, the modified combining - after- decoding scheme based on channel state information （CSI） is proposed. Performance analysis and simulation show that, the modified method increases 2 dB while the PER is 10^-4, and when the numbers of the received station are larger than 5, the performance of modified method is better than that of equal - gain scheme, and close to that of the maximal ratio scheme. This modified method is easy to implement and provides an effective reference for choosing combining scheme in the actual communication.