【作者】 方子明；

【导师】 席丽霞；

【作者基本信息】 北京邮电大学 ， 电子与通信工程（专业学位）， 2013， 硕士

【摘要】 以香农定理为基础,信道编码成为了研究领域之一。如何构造接近信道容量的编码方式、如何设计相应的编码方法及译码方法、如何实现信息的可靠传输和有效传输成为了信道编码领域的重要课题。低密度奇偶校验码(简称LDPC码)是信道编码领域的一个重要的研究成果。它具有如下诸多优点：描述简单、较低的译码复杂度、可以并行实现、使用相对灵活、错误平台较低、可以逼近香农极限等。这些优秀的性能使LDPC码成为当前通信领域的热门研究课题之一,同时也是B3G/4G移动通信系统中的关键研究技术。当前,宽带无线接入技术已经成为必然。在宽带无线通信中,由于多径传输的存在,引起了频率选择性衰落,进而对通信的可靠性造成了严重的影响。采用何种传输技术来有效抵抗多径衰落的影响,针对这类系统的物理层研究成为了研究的热点。单载波频域均衡(SCFDE)系统的出现,给物理层的研究带来了新的方向。SCFDE技术的特点：联合简单的时域反馈均衡、性能上与正交频分复用(OFDM)相似(在高码率的情况下甚至性能更优)、并且没有峰均比大的问题、在相噪和频偏方面也不如OFDM来的敏感、还可以与OFDM技术进行较好的融合等。随着SCFDE技术的发展,它受到了研究者越来越多的关注,并且在宽带无线通信协议IEEE802.16a中SCFDE支术做为建议的物理层传输方案之本论文首先分析了低密度奇偶校验码的组成原理及结构特点,在此基础上提出了两种基于802.16e标准的编码方法,并着重分析了三种通用的译码算法。通过阅读大量的相关文献,提出了适合于802.16e标准的校验矩阵的译码架构,详细的介绍了译码的整个流程及相关步骤,并在此基础上实现了编解码功能合一的LDPC码结构的仿真。其次研究了单载波频域均衡系统,对发射端及接收端进行了框图分析,搭载整个仿真系统,进行了基于单载波频域均衡系统的LDPC码的性能研究。最后得出了在AWGN信道、1344码长、不同码率、不同调制方式、不同多普勒频率下的仿真结果,并进行分析。更多还原

【Abstract】 Based on Shannon theorem, channel coding has become one of the research areas. How to construct close to the channel capacity of the encoding method, how to design a corresponding encoding method and decoding method and how to guarantee information transmission reliable and efficient has become the important subject in channel coding areas.Low Density Parity Check (referred to as the LDPC code) is an important field of channel coding research. It has the following many advantages:simple description, the low decoding complexity, parallel implementation, the use of a relatively flexible, low error platform, may be approaching the Shannon limit and so on. These excellent performance make LDPC codes become one of the the current hot research topics in the field of communications, and is also a key research technology in the B3G/4G mobile communication system.Now,wireless broadBand access technology has become a necessity. In the broadBand wireless communication, due to the presence of multipath transmission, cause frequency selective fading, thereby causing serious influence on the reliability of the communications. What transmission technology to effectively resist the impact of multipath fading, has become a key issue for the study of the physical layer of such systems. The emergence of the single-carrier frequency domain equalization (SCFDE)system, bring a new direction to the study of the physical layer. Technical characteristics of the SCFDE:joint simple time domain feedBack equalizer performance,similar to orthogonal frequency division multiplexing (OFDM)in Performance(even in case of high bit rate performance is more excellent), no PAPR big problem, not sensitive to such OFDM in terms of phase noise and frequency offset, also has better fusion with OFDM technology. With the development of SC-FDE technology, it has been more and more attention in the researchers and SC-FDE technology has been suggested as one of the proposed physical layer transmission schemein in broadBand wireless communication protocol IEEE802.16a.This paper firstly analyzed the principle and structural characteristics of the composition of low density parity check code, proposed two coding method based on the802.16e standard, and analyzed three universal decoding algorithm. By reading a lot of literature, we proposed a decoding architecture suited to802.16e standard check matrix, detaile introduced entire process of decoding steps, and on this basis achieve code structurethe simulation of unity of LDPC codec functions. Secondly, researched dsingle-carrier frequency domain equalization system,analyzed the block diagram of the transmitter and receiver, equipped with the entire simulation system, researched the performance of the LDPC codes based on single-carrier frequency domain equalization system.In AWGN channel,1344yards long, different rate and different modulation schemes under different Doppler frequency we came to the simulation results and analysised all results.更多还原