通信学报
通信學報
통신학보
JOURNAL OF CHINA INSTITUTE OF COMMUNICATIONS
2013年
2期
31-39
,共9页
焦健%杨志华%顾术实%周洁%张钦宇
焦健%楊誌華%顧術實%週潔%張欽宇
초건%양지화%고술실%주길%장흠우
LT码%Tanner 图%随机置换展开%BP译码%停止集
LT碼%Tanner 圖%隨機置換展開%BP譯碼%停止集
LT마%Tanner 도%수궤치환전개%BP역마%정지집
LT codes%Tanner graph%random permute edge-growth%BP decoding%stopping set
针对短码长LT码(码长在103以下)的随机编码方式,需要较高的编码冗余才能保证一定的译码性能的问题.设计了一种基于限制Tanner图连接边随机关系的随机置换展开编码算法,可以实现在较小编码冗余开销下提高短码长 LT 码的可译码概率.在此基础上,针对短码长 LT 码的传统 BP 译码算法效率不高的问题,充分利用BP算法译码失败的停止集剩余信息,设计了采用上述编码算法的短码长LT码的停止集高斯译码算法,可以获得接近最大似然译码的性能.仿真结果表明,所提出的编译码联合算法有效降低了短码长LT码满足10?4译码失败概率时所需的编码冗余开销.
針對短碼長LT碼(碼長在103以下)的隨機編碼方式,需要較高的編碼冗餘纔能保證一定的譯碼性能的問題.設計瞭一種基于限製Tanner圖連接邊隨機關繫的隨機置換展開編碼算法,可以實現在較小編碼冗餘開銷下提高短碼長 LT 碼的可譯碼概率.在此基礎上,針對短碼長 LT 碼的傳統 BP 譯碼算法效率不高的問題,充分利用BP算法譯碼失敗的停止集剩餘信息,設計瞭採用上述編碼算法的短碼長LT碼的停止集高斯譯碼算法,可以穫得接近最大似然譯碼的性能.倣真結果錶明,所提齣的編譯碼聯閤算法有效降低瞭短碼長LT碼滿足10?4譯碼失敗概率時所需的編碼冗餘開銷.
침대단마장LT마(마장재103이하)적수궤편마방식,수요교고적편마용여재능보증일정적역마성능적문제.설계료일충기우한제Tanner도련접변수궤관계적수궤치환전개편마산법,가이실현재교소편마용여개소하제고단마장 LT 마적가역마개솔.재차기출상,침대단마장 LT 마적전통 BP 역마산법효솔불고적문제,충분이용BP산법역마실패적정지집잉여신식,설계료채용상술편마산법적단마장LT마적정지집고사역마산법,가이획득접근최대사연역마적성능.방진결과표명,소제출적편역마연합산법유효강저료단마장LT마만족10?4역마실패개솔시소수적편마용여개소.
Since LT codes adopt the random encoding method, high coding overheads were required for a stable recovery probability of information. a random permute edge-growth-based coding algorithm was proposed, which could enhance the decoding probability of LT code through restricting the random connections between random permutation edges in the Tanner graphs. With this proposed coding algorithm, a decoding algorithm based on stopping set Gaussian elimination was proposed, which efficiently used the redundancy information in the stopping set after the belief propagation decoding. As a result, this decoding scheme could approach the performance of maximum-likelihood decoding. The simulation re-sults show that, the proposed joint design on coding/decoding schemes could obviously reduce the overheads of such short length LT codes as 103, while achieve the decoding failure rate of 10?4.