比特交织编码调制的研究
发布时间：2018-07-28 17:52
【摘要】：摘要：比特交织编码调制(BICM)是一种典型的编码调制技术,它结构简单、性能优异,意在增加编码的多样性,针对TCM灵活性差和在衰落信道中性能差的缺点,在理想交织时将编码器和调制器分离设计,具有高度的灵活性,并可以在衰落信道具有很好的鲁棒性。自从上世纪末被提出以来,BICM一直是编码调制领域中的热点之一。目前已经被广泛应用在各商用无线通信系统中,在未来的光通信领域可能也会实现大规模的应用。但是,它仍存在一些新的技术难点,已知的最优星座映射并不能适应高频谱效率且非规则最优多维星座映射方式并未给出。基于先进编解码技术(LDPC、Turbo)的BICM系统在光通信中的应用研究也越来越受关注,对它的研究有重大的理论意义和实际意义。 本文针对不同的信道类型对已知的多维星座映射进行优化并从信道容量的角度对其进行仿真分析,同时也对基于LDPC码的BICM系统(LDPC-BICM系统)在光纤通信系统中的一些问题进行了研究。主要的工作内容有以下几点： 1.本文先回顾了BICM的基本理论框架。从最优标识的设计优化出发,研究并编写二进制交换算法(BSA),针对AWGN信道和Rayleigh信道运用相应的基于星座距离谱的代价函数对已知的多维星座映射进行优化并给出多种已优化的搜索结果及相应的代价函数值。 2.本文进一步从理想先验信息和无先验信息两种情况考虑,对所得优化多维星座映射下的BICM系统在AWGN信道和Rayleigh信道中容量分别进行仿真,并通过与传统MQAM星座映射下的容量进行对比,意在获得更好的系统渐进性能。另外针对AWGN信道从信道容量出发进一步分析了同一维数下EsNo对优化结果影响。 3.最后,从残余色散和非线性相位噪声的角度对LDPC-BICM系统在光通信的性能进行了研究。通过建立不同的光纤信道模型并简化成相应公式,通过matlab-CML工具对LDPC-BICM系统在光通信中的性能进行仿真并对其残余色散和非线性相位噪声的容忍度进行分析。仿真中采用码长为16200,码率为1/4的标准DVB-S2-LDPC码和软输出解调算法(Max-Log-MAP),映射方式均为16QAM-Gray映射。
[Abstract]:Abstract: bit interleaved coded modulation (BICM) is a typical coding and modulation technique. It is simple in structure and excellent in performance. It is intended to increase the diversity of coding. In view of the disadvantage of TCM flexibility and low neutral energy in fading channels, it is designed to separate the encoder from the modulator in ideal interleaving, with high flexibility and can be used in fading messages. The props have good robustness. Since the end of the last century, BICM has been one of the hotspots in the field of coding and modulation. It has been widely used in commercial wireless communication systems and may also be used in the field of optical communication in the future. However, there are still some new technical difficulties, the best known stars are known. The seat mapping does not adapt to the high frequency spectrum efficiency and the irregular optimal multidimensional constellation mapping method has not been given. The application of BICM system based on advanced codec (LDPC, Turbo) in optical communication is becoming more and more concerned. It has great theoretical and practical significance for its research.
This paper optimizes the known multidimensional constellation mapping for different channel types and simulates it from the angle of channel capacity, and studies some problems in the optical fiber communication system based on the LDPC code based BICM system (LDPC-BICM system). The main work content has the following points:
1. this paper first reviews the basic theoretical framework of BICM. From the optimization of the optimal logo design, we study and write the binary exchange algorithm (BSA), and optimize the known multidimensional constellation mapping for the AWGN channel and the Rayleigh channel based on the corresponding cost function based on the constellation distance spectrum, and give a variety of optimized search results and corresponding results. The value of the cost function.
2. considering the two conditions of ideal prior information and no prior information, this paper simulates the capacity of the BICM system in the AWGN channel and the Rayleigh channel under the multi-dimensional constellation mapping, and compares it with the capacity of the traditional MQAM constellation, so as to obtain better system progressive performance. In addition, the AWGN system is aimed at AWGN. From the channel capacity, the channel further analyzes the influence of EsNo on the optimization result under the same dimension.
3. finally, the performance of LDPC-BICM system in optical communication is studied from the angle of residual dispersion and nonlinear phase noise. By establishing different optical fiber channel models and simplifying the corresponding formula, the performance of LDPC-BICM system in optical communication is simulated by matlab-CML tool, and its residual dispersion and nonlinear phase noise are made. The tolerance is analyzed. In the simulation, the standard DVB-S2-LDPC code and the soft output demodulation algorithm (Max-Log-MAP) with code length of 16200, the rate of 1/4 and the soft output demodulation algorithm (Max-Log-MAP) are all mapped.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1
本文编号：2151135
[Abstract]:Abstract: bit interleaved coded modulation (BICM) is a typical coding and modulation technique. It is simple in structure and excellent in performance. It is intended to increase the diversity of coding. In view of the disadvantage of TCM flexibility and low neutral energy in fading channels, it is designed to separate the encoder from the modulator in ideal interleaving, with high flexibility and can be used in fading messages. The props have good robustness. Since the end of the last century, BICM has been one of the hotspots in the field of coding and modulation. It has been widely used in commercial wireless communication systems and may also be used in the field of optical communication in the future. However, there are still some new technical difficulties, the best known stars are known. The seat mapping does not adapt to the high frequency spectrum efficiency and the irregular optimal multidimensional constellation mapping method has not been given. The application of BICM system based on advanced codec (LDPC, Turbo) in optical communication is becoming more and more concerned. It has great theoretical and practical significance for its research.
This paper optimizes the known multidimensional constellation mapping for different channel types and simulates it from the angle of channel capacity, and studies some problems in the optical fiber communication system based on the LDPC code based BICM system (LDPC-BICM system). The main work content has the following points:
1. this paper first reviews the basic theoretical framework of BICM. From the optimization of the optimal logo design, we study and write the binary exchange algorithm (BSA), and optimize the known multidimensional constellation mapping for the AWGN channel and the Rayleigh channel based on the corresponding cost function based on the constellation distance spectrum, and give a variety of optimized search results and corresponding results. The value of the cost function.
2. considering the two conditions of ideal prior information and no prior information, this paper simulates the capacity of the BICM system in the AWGN channel and the Rayleigh channel under the multi-dimensional constellation mapping, and compares it with the capacity of the traditional MQAM constellation, so as to obtain better system progressive performance. In addition, the AWGN system is aimed at AWGN. From the channel capacity, the channel further analyzes the influence of EsNo on the optimization result under the same dimension.
3. finally, the performance of LDPC-BICM system in optical communication is studied from the angle of residual dispersion and nonlinear phase noise. By establishing different optical fiber channel models and simplifying the corresponding formula, the performance of LDPC-BICM system in optical communication is simulated by matlab-CML tool, and its residual dispersion and nonlinear phase noise are made. The tolerance is analyzed. In the simulation, the standard DVB-S2-LDPC code and the soft output demodulation algorithm (Max-Log-MAP) with code length of 16200, the rate of 1/4 and the soft output demodulation algorithm (Max-Log-MAP) are all mapped.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1
【参考文献】
相关期刊论文 前3条
1 谢求亮;彭克武;潘长勇;杨知行;;比特交织LDPC编码调制系统中的迭代解映射和译码算法[J];清华大学学报(自然科学版)网络.预览;2009年08期
2 黄平;姜明;赵春明;;LDPC编码调制系统中基于反馈LLR均值的迭代解调/译码算法[J];电子与信息学报;2008年08期
3 许楠;刘立人;刘德安;孙建锋;栾竹;;自由空间相干光通信技术及发展[J];激光与光电子学进展;2007年08期
相关博士学位论文 前1条
1 何善宝;低密度奇偶校验码及其应用研究[D];东南大学;2005年
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