协作通信系统中联合LDPC-网络编码的研究

发布时间：2018-04-01 09:03

本文选题：协作通信　切入点：低密度奇偶校验码　出处：《辽宁工业大学》2016年硕士论文

【摘要】：数据信号在无线信道传输中难免会受到噪声污染和产生多径衰落等问题。针对以上问题,基于协作通信系统的两信源单信宿网络传输模型,将LDPC(Low Density Parity Check Code,低密度奇偶校验码)编码和网络编码技术进行联合研究,从而降低传输系统的误码率,提高传输系统的可靠性。论文先对无线信道的传输特性进行概述,对比和分析高斯信道、瑞利衰落信道和莱斯衰落信道三种传输模型,并选择瑞利衰落信道模型为研究传输模型;另外,对协作通信、LDPC编码和网络编码三种关键技术的原理进行解析,说明三种技术联合研究的必要性,并重点研究和分析网络编码技术的国内外研究现状以及发展方向。基于瑞利衰落信道的两信源单信宿网络传输模型,对直接传输方案、中继节点协作网络编码传输方案和节点间协作网络编码传输方案的信息传输过程进行对比和分析,并对这三种传输方案的误码率和中断概率进行仿真和理论分析,由仿真结果得出:三种传输方案中,节点间协作网络编码传输方案的误码率和中断概率最低,传输性能最好。并基于节点间协作通信模型,对联合LDPC-网络编码传输方案进行误码率仿真和分析,仿真可知,这种传输方案的误码率比节点间协作网络编码传输方案的误码率更低,可靠性得到提高。基于节点间协作网络编码传输方案中信道增益与误码率成负相关的特性,对目的节点接收信息的处理进行改进,具体做法如下:信道增益越大,在输出合并信息时的加权系数所占比例就越大。并对改进方案和节点间协作网络编码传输方案的传输数据时间和误码率之差进行仿真实验,实验结果得出:改进方案通过牺牲极小的误码率来增加传输速率。
[Abstract]:The data signal is inevitably polluted by noise and multipath fading in wireless channel transmission.Aiming at the above problems, the LDPC(Low Density Parity Check code (LDPC(Low Density Parity Check code) coding and network coding technology are studied based on the two-source single-host network transmission model of cooperative communication system, so as to reduce the bit error rate (BER) of the transmission system.Improve the reliability of transmission system.Firstly, the thesis summarizes the transmission characteristics of wireless channel, compares and analyzes three transmission models: Gao Si channel, Rayleigh fading channel and Rice fading channel, and selects Rayleigh fading channel model as the transmission model.The principle of LDPC coding and network coding for cooperative communication is analyzed, and the necessity of joint research of these three technologies is explained. The current research situation and development trend of network coding technology at home and abroad are emphatically studied and analyzed.Based on Rayleigh fading channel, the information transmission process of direct transmission scheme, relay node cooperative network coding scheme and inter-node cooperative network coding transmission scheme is compared and analyzed.The error rate and interrupt probability of the three transmission schemes are simulated and analyzed theoretically. The simulation results show that: among the three transmission schemes, the bit-error rate and the interrupt probability of the cooperative network coding transmission scheme are the lowest, and the transmission performance is the best.Based on the cooperative communication model between nodes, the bit error rate of the joint LDPC-network coding transmission scheme is simulated and analyzed. The simulation results show that the BER of this transmission scheme is lower than that of the inter-node cooperative network coding transmission scheme.Reliability is improved.Based on the negative correlation between channel gain and bit error rate (BER) in the cooperative network coding transmission scheme between nodes, this paper improves the processing of the information received by the destination node as follows: the greater the channel gain, the greater the channel gain.The greater the proportion of weighting coefficients in the output of the combined information.Simulation experiments on the difference between the transmission time and bit error rate of the improved scheme and the cooperative network coding transmission scheme between nodes are carried out. The experimental results show that the improved scheme increases the transmission rate by sacrificing minimal bit error rate.
【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN911.22

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