武汉轻工大学学报
武漢輕工大學學報
무한경공대학학보
Journal of Wuhan Polytechnic University
2015年
2期
83-86
,共4页
余结%王防修%胡迪%熊海梦%胡义
餘結%王防脩%鬍迪%熊海夢%鬍義
여결%왕방수%호적%웅해몽%호의
香农编码%优化算法%编码效率%改进算法%选择排序
香農編碼%優化算法%編碼效率%改進算法%選擇排序
향농편마%우화산법%편마효솔%개진산법%선택배서
shannon code%optimization algorithm%coding efficiency%improved algorithm%selection sort
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。
針對香農編碼優化算法在編碼效率方麵存在的不足,提齣一種基于信源符號碼字重新分配而使平均碼長變短的優化算法。新算法在原優化算法的基礎上,通過判斷優化碼的碼長是否隨概率的遞減而遞增來決定該優化碼是否需要進一步優化。鑒于改進算法隻對優化碼的碼長不是隨概率的遞減而遞增的情形纔有效,首先設計一箇優化碼能否改進的判斷算法,通過對優化碼的判斷,然後對能進一步優化的優化碼用改進算法優化。改進算法用選擇排序算法對優化碼進行重新分配,使得分配後的碼字滿足碼長隨概率的遞減而遞增。算例倣真錶明,對能進一步優化的優化碼,改進算法可以進一步提高優化算法的編碼效率。
침대향농편마우화산법재편마효솔방면존재적불족,제출일충기우신원부호마자중신분배이사평균마장변단적우화산법。신산법재원우화산법적기출상,통과판단우화마적마장시부수개솔적체감이체증래결정해우화마시부수요진일보우화。감우개진산법지대우화마적마장불시수개솔적체감이체증적정형재유효,수선설계일개우화마능부개진적판단산법,통과대우화마적판단,연후대능진일보우화적우화마용개진산법우화。개진산법용선택배서산법대우화마진행중신분배,사득분배후적마자만족마장수개솔적체감이체증。산례방진표명,대능진일보우화적우화마,개진산법가이진일보제고우화산법적편마효솔。
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.