低密度奇偶校验码在空间通信中的关键技术研究

发布时间：2018-01-05 11:12

本文关键词：低密度奇偶校验码在空间通信中的关键技术研究　出处：《中国科学院国家空间科学中心》2017年博士论文　论文类型：学位论文

【摘要】：低密度奇偶校验(LDPC)码是最接近香农极限的纠错码之一,具有优良的性能,受到工业界的广泛关注。在移动通信领域,3GPP和IEEE等标准化组织都推荐了自己的LDPC码方案作为移动通信信道编码标准。在空间通信领域,ETSI和CCSDS等空间通信的标准化组织也选择合适的LDPC码方案作为空间通信的信道编码标准。根据空间通信的特点,LDPC码作为信道编码方案的关键技术主要包括近地空间通信和深空通信中要求的高速率编码、多码率兼容编码、低功耗编译码等。本文针对这几种关键技术的应用场景展开分析和研究,主要的研究工作如下:1、在面向空间超高速通信应用场景中,本文在CCSDS标准推荐7/8码率LDPC串行编码架构的基础上提出并实现了一种低并行度编码方法,然后通过对低并行度编码方法的优化提出一种编码吞吐率达2.5Gbps的超高速LDPC编码架构,并给出了这种超高速编码架构的硬件实现结果和分析。2、在面向空间通信低功耗应用场景中,本文在低并行度编码方法基础上提出了一种可配置循环矩阵高效率低并行度LDPC编码方法和编码器实现架构。通过在编码器的循环移位器中加入合适的循环移位器控制器,使得循环移位器可以根据输入的待编码信息位的特点选择移位次数,从而降低编码过程中循环移位器的平均移位次数,达到降低编码功耗的目的。文中针对CCSDS标准推荐7/8码率LDPC码给出了移位控制算法和编码架构。3、在面向空间通信中的可变编码调制应用场景中,欧洲电信标准协会(ETSI)提出了第二代数字视频广播标准(DVB-S2)。该标准推荐使用了BCH码和LDPC码的级联码作为信道编码方案。本文在DVB-S2标准推荐的多码率兼容的编码算法基础上,提出一种新的多码率兼容的LDPC编码电路架构,能够实现DVB-S2标准中所有11种码率的兼容编码,并给出了这种编码架构的硬件实现结果和分析。4、CCSDS在2016年春天发布的蓝皮书中推荐三种超短码长LDPC码作为下一代上行链路的信道编码方案。论文研究这种超短码的结构特性,给出合适的编译码算法和架构设计方案。在编码方面,采用优化的并行编码的方案,给出了高效的编码架构设计;在译码方面,根据超短码的校验矩阵特点,推荐一种高效低耦合译码算法,能够加快迭代收敛速度,且根据译码算法提出了(256,128)LDPC码的译码器架构设计。这种超短LDPC码具有编译码器结构简单、占用逻辑资源少的特点,在未来空间通信上行链路中具有很大的应用前景。
[Abstract]:Low density parity check (LDPC) code is the most close to the Shannon limit error correcting codes, with excellent performance, attracted much attention in the industrial sector. In the field of mobile communication, 3GPP and IEEE and other standardization organizations have recommended their own LDPC code scheme as a mobile communication channel encoding standard. In the field of space communications, standard organization of ETSI and CCSDS also choose appropriate space communication LDPC codes as channel encoding standard space communication. According to the characteristics of space communication, LDPC codes as the key technology of channel encoding scheme mainly includes the requirement of high speed near space communication and deep space communication encoding, multi rate compatible encoding, low-power codec etc. This paper analyzes and studies the application scenes of the several key technologies, the main research work is as follows: 1, in the space for ultra high speed communication scenarios, based on the CCSDS standard recommended Based 7/8 rate LDPC serial encoding architecture is proposed and implemented on a low degree of parallel encoding method, and then through the optimization of the encoding method of parallel low proposes an encoding throughput rate of 2.5Gbps ultra high speed LDPC encoding architecture, and gives the ultra high speed encoding architecture hardware implementation results and analysis in.2. For low power application scenarios in space communication, the parallel degree based encoding method at low forward a configurable cyclic matrix with high efficiency and low degree of parallel LDPC encoding method and encoder architecture. Through the encoder cycle shift into a suitable cycle in shift controller, the cycling shifter can shift the number according to the selected the characteristics of encoding bits of information input, thereby reducing the encoding process for the cyclic shift of the mean shift times, to reduce the power consumption of the encoding according to the CCSDS standard. Quasi 7/8 recommended LDPC code gives the shift control algorithm and.3 encoding architecture, for variable encoding modulation scenarios in space communication in the European Telecommunications Standards Institute (ETSI) put forward the second generation digital video broadcasting standard (DVB-S2). The standard recommended the use of the concatenated code BCH code and LDPC code as channel encoding based on the DVB-S2 standard recommended scheme. Multi rate compatible encoding algorithm based on LDPC encoding circuit architecture proposed a new multi rate compatible, can realize the compatible encoding standard DVB-S2 all 11 rate, and gives the results of implementation and analysis of.4 encoding the architecture of the hardware, CCSDS released in the spring of 2016 Blue Book recommend three kinds of short code length LDPC codes as channel encoding scheme for next generation uplink. This thesis structure characteristics of ultrashort code, given appropriate decoding algorithm and architecture design Plan. In the aspect of encoding, using parallel encoding optimization scheme, gives the efficient encoding architecture; in decoding, according to the characteristics of short code parity check matrix, recommended a low coupling decoding algorithm can accelerate the convergence speed, and according to the decoding algorithm (256128) decoder architecture design LDPC code this code is LDPC. The ultrashort codec has the advantages of simple structure, the advantages of less logic resources, has great application prospect in the future space communication in the uplink.

【学位授予单位】：中国科学院国家空间科学中心
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN927

【相似文献】