数字音频广播信道编码研究与设计

发布时间：2018-12-18 14:49

【摘要】：数字音频广播与传统模拟广播相比,具有音质更出众、抗干扰能力更强、频谱利用率更高、覆盖范围更广、更适合高速移动接收等优点。数字音频广播是广播技术发展的必然趋势,也将为我国带来巨大的产业效益和社会效用。当前,国际上的数字音频广播主要有三种技术方案,分别是：Eureka-147DAB数字音频广播系统、DRM/DRM+数字调幅广播系统、HD Radio带内同频系统。三种技术方案各有其优缺点和适用性。2006年,国家广播电视总局基于DAB标准,正式出台了《30 MHz～3000 MHz地面数字音频广播系统技术规范》作为我国的数字音频广播行业标准。但由于政策、专利、兼容性等问题,至今没有获得推广应用。因此,探索和研究适合我国应用和发展、具有自主知识产权的数字音频广播方案显得十分迫切和重要。信道编码调制技术是数字音频广播的核心技术之一。本文首先深入研究了DAB基带传输系统的关键技术,并基于MATLAB平台对DAB信道编码调制系统进行仿真设计与分析。其次,针对DAB系统采用的COFDM技术,分别对卷积码、RS码、级联码、Turbo码、LDP C码几种高效信道编码及其在数字音频广播中的适用性进行研究,对比了不同信道编码方案的译码性能,证明了QC-LDPC码能提供更强的抗干扰能力,更适合应用于数字音频广播系统。在此基础上,本文提出了基于QC-LDPC码的数字音频广播基带系统的设计方案,并通过MATLAB仿真平台,研究了QC-LDPC码的码长、码率、译码迭代次数等因素对译码性能的影响。近期我国新一代数字音频广播标准CDR的制定工作取得阶段性成果。该系统将QC-LDPC码选作为其信道编码方案,与本文的前期研究成果相吻合。根据CDR提供的QC-LDPC码的结构特点,本文设计了一种基于SRAA电路的QC-LDPC编码器。利用ModelSim和MATLAB仿真软件,对编码过程进行了验证,结果表明该编码器能对信息进行正确编码。QC-LDPC码是CDR信道编码的核心模块,本文课题的研究成果对于后续数字音频广播系统的设计与相关产品的开发具有重要的意义。
[Abstract]:Compared with traditional analog broadcasting, digital audio broadcasting has more outstanding sound quality, stronger anti-jamming ability, higher spectrum efficiency, wider coverage and more suitable for high-speed mobile reception. Digital audio broadcasting is an inevitable trend in the development of broadcasting technology and will bring huge industrial benefits and social utility to our country. At present, there are three technical schemes for digital audio broadcasting in the world, namely, Eureka-147DAB digital audio broadcasting system and DRM/DRM digital amplitude modulation broadcasting system, HD Radio in-band co-frequency system. In 2006, the State Administration of Radio and Television, based on DAB standard, formally issued < 30 MHz~3000 MHz terrestrial digital audio broadcasting system technical specification as the digital audio broadcasting industry standard in China. However, due to policy, patents, compatibility and other issues, so far has not been promoted and applied. Therefore, it is very urgent and important to explore and study the digital audio broadcasting scheme which is suitable for the application and development of our country and has its own intellectual property rights. Channel coded modulation is one of the core technologies of digital audio broadcasting. In this paper, the key technologies of DAB baseband transmission system are studied, and the simulation design and analysis of DAB channel coded modulation system based on MATLAB platform are carried out. Secondly, aiming at the COFDM technology used in DAB system, the high efficient channel codes such as convolutional code, RS code, concatenated code and Turbo, LDP C code and their applicability in digital audio broadcasting are studied respectively. The decoding performance of different channel coding schemes is compared. It is proved that QC-LDPC code can provide stronger anti-jamming ability and is more suitable for digital audio broadcasting system. On this basis, this paper proposes a design scheme of digital audio broadcasting baseband system based on QC-LDPC code, and studies the influence of code length, code rate and decoding iteration number of QC-LDPC code on the decoding performance through MATLAB simulation platform. In recent years, the establishment of the new generation digital audio broadcasting standard CDR has been achieved. In this system, QC-LDPC code is chosen as its channel coding scheme, which is consistent with the previous research results in this paper. According to the structure characteristic of QC-LDPC code provided by CDR, a QC-LDPC encoder based on SRAA circuit is designed in this paper. The coding process is verified by using ModelSim and MATLAB simulation software. The results show that the encoder can encode the information correctly. QC-LDPC code is the core module of CDR channel coding. The research results of this paper are of great significance for the design of the subsequent digital audio broadcasting system and the development of related products.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN934.3

【相似文献】