LDPC编译码方法与应用.doc

. . . 摘 要 随着无线通信技术的不断发展与进步，数字电视广播、移动视频点播等对数据吞吐量要求很高的业务逐渐变得可能。为了在有限的带宽内用有限的发射功率保证信息在空间传播时的可靠性，需要在系统中引入具有很强纠错能力的信道编码技术。低密度奇偶校验码（LDPC）码具有与香农限非常接近的纠错性能，因此成为现代通信系统中信道编码的强有力竞争者。 目前，包括欧洲数字电视卫星广播标准DVB-S2、中国数字电视地面广播标准CDTV-T 等在内的标准已经将LDPC 码作为信道编码的解决方案，而IEEE 802.11n、IEEE 802.16e等无线局/城域网标准也将LDPC 码作为一种候选方案。随着LDPC 码进入应用的脚步不断加快，有必要对LDPC 码在实现过程中存在的问题和困难进行研究并加以解决和克服，这也正是本文对LDPC 码的实现与应用进行研究的出发点。本文介绍了LDPC 码,综述了其编码方法和译码方法,同时对LDPC 码编译码方法的发展作了分析。 关键词:LDPC 码;编码;译码;奇偶校验矩阵 Abstract With the development of wireless communication technology, wirelessservices that require high data throughput, such as digital TV broadcastingand mobile TV, have been increasingly practical. In order to ensure thereliability of communication with limited bandwidth and limited transmission power, we need to implant powerful channel coding technique into the system. Low-density parity-check codes, with the error-correcting ability approaching Shannon limit very closely, are therefore highly competitive candidate of channel codes in modern communication systems. In present,European digital TV satellite broadcasting standard DVB-S2 and Chinese digital TV terrestrial broadcasting standard CDTV-T have chosen LDPC codes as the channel codes while wireless local/metropolitan area network(WLAN/WMAN) standards IEEE 802.11n and IEEE 802.16e have considered LDPC codes as an option for channel codes. Therefore, it is necessary to study the difficulties and solve the problems on the way of applying LDPC codes into practical systems, which is the point this thesis mainly addresses.While briefly introducing LDPC codes are introduced briefly ,this paper summarizes the encoding and decoding algorithms. The development of encoding and decoding methods is analyzed as well . Key words : LDPC codes ; encoding ; decoding ; parity check matrix 目录 TOC \o 1-3 \h \z \u 摘 要 1 Abstract 2 第一