基于网格图的同步错误纠错码研究
发布时间：2018-11-13 15:36
【摘要】：同步错误,包括符号的插入与删节,存在于各类通信与存储系统中,如无线光通信中的差分脉冲位置调制(Differential Pulse-Position Modulation,DPPM)系统、比特图形化介质(Bit Patterned Media,BPM)存储系统等。研究者们设计了各种可纠正同步错误的纠错码方案,其中一种为基于扩展网格图的卷积码方案,该方案可同时纠正卷积码接收序列中的插入、删节和替代错误。基于此,本文面向DPPM系统中的同步错误,研究基于扩展网格图的卷积码处理方案。针对DPPM中同步错误的具体特点,本文设计了一种迭代检测译码方案。该方案以DPPM符号序列的软判决检测算法和纠正同步错误的卷积码译码方案为基础,利用不同的DPPM符号调制后的码片长度不等这一特点,将译码后再重新编码调制得到的码片长度和迭代次数作为判决条件,在软判决检测和基于删剪网格图的维特比译码器之间进行迭代。仿真结果表明,与未迭代系统相比,该方案可有效降低误帧率,获得较大的性能增益。进一步,为改善DPPM系统中卷积码编译码方案的纠错性能,本文将Reed-Solomon(RS)码级联卷积码方案应用到DPPM系统中。该方案采用卷积码作为内码纠正部分同步错误和替代错误,利用RS码作为外码纠正由于信道和内码误同步造成的突发性替代错误。仿真结果表明,该方案可有效纠正DPPM系统中插入、删节和替代错误。综上所述,本文针对DPPM系统中的同步问题,提出了一种迭代检测译码算法,并将RS码级联卷积码的方案应用至DPPM系统中。
[Abstract]:Synchronous errors, including the insertion and deletion of symbols, are present in various communication and storage systems, such as differential pulse position modulation (Differential Pulse-Position Modulation,DPPM) systems in wireless optical communications, bitwise graphical media (Bit Patterned Media, BPM) storage system, etc. Researchers have designed a variety of error-correcting schemes to correct synchronous errors, one of which is an extended trellis graph based convolutional code scheme, which can correct the insertion, deletion and substitution errors in the receiving sequence of the convolutional code at the same time. Based on this, this paper studies the convolutional code processing scheme based on extended trellis graph for synchronization errors in DPPM system. According to the characteristics of synchronous errors in DPPM, this paper designs an iterative detection decoding scheme. This scheme is based on the soft decision detection algorithm of DPPM symbol sequence and the convolutional code decoding scheme which corrects synchronous errors. It makes use of the different length of the code chip modulated by different DPPM symbols. The length and the number of iterations obtained from the decoding and re-coding modulation are taken as the decision conditions, and iterations are carried out between the soft-decision detection and the Viterbi decoder based on truncated trellis graph. The simulation results show that the proposed scheme can effectively reduce the frame error rate and obtain a large performance gain compared with the non-iterative system. Furthermore, in order to improve the error correction performance of convolutional code encoding and decoding scheme in DPPM system, the concatenated convolutional code scheme of Reed-Solomon (RS) code is applied to DPPM system in this paper. In this scheme, convolutional codes are used as internal codes to correct partial synchronization errors and substitution errors, and RS codes are used as outer codes to correct sudden substitution errors caused by channel and internal code error synchronization. The simulation results show that the scheme can effectively correct the insertion, deletion and substitution errors in DPPM system. To sum up, this paper proposes an iterative detection and decoding algorithm for synchronization in DPPM systems, and applies the scheme of concatenated convolutional codes of RS codes to DPPM systems.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.22
本文编号：2329573
[Abstract]:Synchronous errors, including the insertion and deletion of symbols, are present in various communication and storage systems, such as differential pulse position modulation (Differential Pulse-Position Modulation,DPPM) systems in wireless optical communications, bitwise graphical media (Bit Patterned Media, BPM) storage system, etc. Researchers have designed a variety of error-correcting schemes to correct synchronous errors, one of which is an extended trellis graph based convolutional code scheme, which can correct the insertion, deletion and substitution errors in the receiving sequence of the convolutional code at the same time. Based on this, this paper studies the convolutional code processing scheme based on extended trellis graph for synchronization errors in DPPM system. According to the characteristics of synchronous errors in DPPM, this paper designs an iterative detection decoding scheme. This scheme is based on the soft decision detection algorithm of DPPM symbol sequence and the convolutional code decoding scheme which corrects synchronous errors. It makes use of the different length of the code chip modulated by different DPPM symbols. The length and the number of iterations obtained from the decoding and re-coding modulation are taken as the decision conditions, and iterations are carried out between the soft-decision detection and the Viterbi decoder based on truncated trellis graph. The simulation results show that the proposed scheme can effectively reduce the frame error rate and obtain a large performance gain compared with the non-iterative system. Furthermore, in order to improve the error correction performance of convolutional code encoding and decoding scheme in DPPM system, the concatenated convolutional code scheme of Reed-Solomon (RS) code is applied to DPPM system in this paper. In this scheme, convolutional codes are used as internal codes to correct partial synchronization errors and substitution errors, and RS codes are used as outer codes to correct sudden substitution errors caused by channel and internal code error synchronization. The simulation results show that the scheme can effectively correct the insertion, deletion and substitution errors in DPPM system. To sum up, this paper proposes an iterative detection and decoding algorithm for synchronization in DPPM systems, and applies the scheme of concatenated convolutional codes of RS codes to DPPM systems.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.22
【参考文献】
相关期刊论文 前1条
1 张译方;陈为刚;;纠正DPPM中插入删节错误的纠错码方案[J];信息技术;2014年08期
，本文编号：2329573
本文链接：https://www.wllwen.com/kejilunwen/wltx/2329573.html
