一种香农编码优化算法的改进

摘要

针对香农编码优化算法在编码效率方面存在的不足，提出一种基于信源符号码字重新分配而使平均码长变短的优化算法。新算法在原优化算法的基础上，通过判断优化码的码长是否随概率的递减而递增来决定该优化码是否需要进一步优化。鉴于改进算法只对优化码的码长不是随概率的递减而递增的情形才有效，首先设计一个优化码能否改进的判断算法，通过对优化码的判断，然后对能进一步优化的优化码用改进算法优化。改进算法用选择排序算法对优化码进行重新分配，使得分配后的码字满足码长随概率的递减而递增。算例仿真表明，对能进一步优化的优化码，改进算法可以进一步提高优化算法的编码效率。%Aiming at the deficiency in shannon coding optimization algorithm, this paper presents an optimization al-gorithma which redistributs lcodeword to source symbols and makes the average code length shorter.The new algo-rithm which is on the basis of the original optimization algorithm, and uses the code length to determine optimal codes increases with probability decreases ,and judge whether the optimized code is in need of further optimization. In view of the improved algorithm which is effective to optimize the code length that does not increases with the probability of decreasing ,this paper designs a judgment algorithm to decide whether the optimized code can be im-proved.By judging to the optimized code, it uses the improved algorithm to optimize the optimization code.The im-proved algorithm uses selection sort algorithm to redistribute the optimized code, the distribution of codewords satis-fy code length increasing with the probability descreasing.Simulation results show that, for the further optimization of the energy of the optimized code, the improved algorithm can further improve the coding efficiency of optimization algorithm.