M序列报文的MIAC压缩编码算法

A MIAC Compression Algorithm for M Sequence Message

M序列报文是典型短波数据链报文。提出一种针对M序列报文的MIAC压缩编码算法，该算法根据M序列报文的统计特性，应用基于字段结构的半动态概率估计模型，量化低概率符号出现概率的取值且半动态更新，采用动态的编码区间长度更新机制，使乘法运算替换为预处理过程中的查表运算，最大造成10．04％的编码效率损失。测试结果表明，当M序列报文数目为2～9条时，MIAC压缩编码算法在损失最多20％的压缩率时，使压缩时间低于原算术编码至少50％。为今后研究提升数据链系统性能提供一种新的思路。

M sequence message is a typical message of HF data link. According to the statistical properties of M sequence message, this paper puts forward a new improved arithmetic coding, i.e. a semi-fixed proba- bility estimative model based on frame structure proposed to quantify the probability of low probability symbols, a dynamic update mechanism of encoding interval length applied to update discretely encoding in- terval length in real time, and the algorithm caused the coding efficiency loss up to 10.04~/6. The test re- sults show that when the quantity of M sequence message is from 2 to 9 and MIAC compression coding al- gorithm loses its compression ratio by 20 % at most, compression time of the improved algorithm is lower than the original arithmetic coding at least 50%. And this will provide a new way of thinking for the study of the performance of data link system in the future.