基于IEEE802.16e协议的无短环的LDPC缩短码设计  

Design of shortened LDPC codes based on IEEE802.16e protocol without short cycles

作　　者：崔媛媛[1] 徐荣青[1] 潘欣艳[1] 王玉杰[1] 关丽[1] 王斌斌[1] 

机构地区：[1]南京邮电大学光电工程学院,南京210046

出　　处：《计算机应用》2011年第12期3207-3209,共3页journal of Computer Applications

基　　金：国家自然科学基金面上项目(60778007)

摘　　要：IEEE802.16e协议给出的低密度奇偶校验(LDPC)码是短码时,其校验矩阵存在大量的短环,针对这一问题,设计了一种新的LDPC缩短码方案。该方案在现有的IEEE802.16e协议的LDPC码的校验矩阵设计框架下,提出一种分块修正子校验矩阵的方法,该方法用准循环矩阵法和有限几何法联合优化的方法构造了扩展因子zf=48的校验矩阵,运用同步顺序搜索度数节点的方式,使缩短码情况下的校验矩阵无4环并且仅含有少量6环。在加性高斯白噪声(AWGN)信道下仿真实验表明,码率为0.5的情况下,改进后的码字不仅保持了IEEE802.16e协议编码的快速编码的性能,并且误码率性能仅比此时的香农限多了1.1 dB。The shortened LDPC codes,based on the current IEEE802.16e standard,have plenty of small girths.In order to resolve this problem,this paper proposed a new scheme of designing the shortened LDPC codes.In the proposed scheme,the design has modified the sub-parity check matrix under the frame of the IEEE802.16e Standard.The proposed check matrix with the spreading factor（zf=48） was constructed with quasi-cyclic matrix method and finite geometry method.Moreover,parity check points searched the node degree in synchronous sequence,and the proposed sub-parity check matrix has minor girth-6 and no girth-4.The results of simulation in the AWGN（Additive White Gaussion Noise） channels show that the improved short code with the code rate approaching to 0.5,can fast encode as excellently as the IEEE802.16e protocol.Moreover,a good BER（Bit Error Rate） performance of the proposed code is 1.1 dB more than the Shannon limit of this channel.

关 键 词：低密度奇偶校验码 缩短码 IEEE802.16e协议 短环 编码算法 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]