基于非等重保护的变长编码纠错方案  

UEP-based error-correcting scheme for variable-length codes

作　　者：范晨[1] 崔慧娟[1] 唐昆[1] 

机构地区：[1]清华大学电子工程系微波与数字通信技术国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2003年第9期1261-1264,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(69972020);国家"九八五"基础研究项目(G1998030406)

摘　　要：由于变长编码所固有的易于误码扩散的弱点,传统的纠错编码并不能高效地解决变长编码的差错控制问题。结合变长编码的网格结构,该文提出了一种新的基于非等重保护的变长编码纠错方案。通过将变长编码的网格状态引入到纠错编码的校验比特生成中,从而对变长码的网格路径加以较重的保护,在一定程度上抑制了变长码的误码扩散。相对传统纠错编码,该方案对于变长码的纠错能力有了明显的提高,在误符号率为10-2、信道编码效率为2/3时,Eb/N0有1.7dB左右的增益。Since variablelength codes (VLC) are inherently vulnerable to errors, traditional errorcorrecting codes are unable to efficiently handle VLC error control problems. An errorcorrecting scheme was developed for VLC based on unequal error protection (UEP). Information from the trellis state of the VLC encoding is incorporated into the generation of the parity bits, so that the VLC encoding trellis path is more heavily protected and the error propagation is reduced. A modified VLCMAP algorithm is implemented as the joint sourcechannel decoder. The proposed scheme significantly outperforms traditional errorcorrecting codes in terms of symbol error rate with a 1.7 dB gain in Eb/N0 when the channel coding rate is 2/3 and the symbol error rate is 0.01.

关 键 词：通信理论 变长编码 非等重保护 纠错编码 误码扩散 网格路径 信源信道联合译码 

分 类 号：TN911.22[电子电信—通信与信息系统]