比特交織編碼調(diào)制的研究
發(fā)布時間：2018-07-28 17:52
【摘要】：摘要：比特交織編碼調(diào)制(BICM)是一種典型的編碼調(diào)制技術,它結構簡單、性能優(yōu)異,意在增加編碼的多樣性,針對TCM靈活性差和在衰落信道中性能差的缺點,在理想交織時將編碼器和調(diào)制器分離設計,具有高度的靈活性,并可以在衰落信道具有很好的魯棒性。自從上世紀末被提出以來,BICM一直是編碼調(diào)制領域中的熱點之一。目前已經(jīng)被廣泛應用在各商用無線通信系統(tǒng)中,在未來的光通信領域可能也會實現(xiàn)大規(guī)模的應用。但是,它仍存在一些新的技術難點,已知的最優(yōu)星座映射并不能適應高頻譜效率且非規(guī)則最優(yōu)多維星座映射方式并未給出。基于先進編解碼技術(LDPC、Turbo)的BICM系統(tǒng)在光通信中的應用研究也越來越受關注,對它的研究有重大的理論意義和實際意義。 本文針對不同的信道類型對已知的多維星座映射進行優(yōu)化并從信道容量的角度對其進行仿真分析,同時也對基于LDPC碼的BICM系統(tǒng)(LDPC-BICM系統(tǒng))在光纖通信系統(tǒng)中的一些問題進行了研究。主要的工作內(nèi)容有以下幾點： 1.本文先回顧了BICM的基本理論框架。從最優(yōu)標識的設計優(yōu)化出發(fā),研究并編寫二進制交換算法(BSA),針對AWGN信道和Rayleigh信道運用相應的基于星座距離譜的代價函數(shù)對已知的多維星座映射進行優(yōu)化并給出多種已優(yōu)化的搜索結果及相應的代價函數(shù)值。 2.本文進一步從理想先驗信息和無先驗信息兩種情況考慮,對所得優(yōu)化多維星座映射下的BICM系統(tǒng)在AWGN信道和Rayleigh信道中容量分別進行仿真,并通過與傳統(tǒng)MQAM星座映射下的容量進行對比,意在獲得更好的系統(tǒng)漸進性能。另外針對AWGN信道從信道容量出發(fā)進一步分析了同一維數(shù)下EsNo對優(yōu)化結果影響。 3.最后,從殘余色散和非線性相位噪聲的角度對LDPC-BICM系統(tǒng)在光通信的性能進行了研究。通過建立不同的光纖信道模型并簡化成相應公式,通過matlab-CML工具對LDPC-BICM系統(tǒng)在光通信中的性能進行仿真并對其殘余色散和非線性相位噪聲的容忍度進行分析。仿真中采用碼長為16200,碼率為1/4的標準DVB-S2-LDPC碼和軟輸出解調(diào)算法(Max-Log-MAP),映射方式均為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.
【學位授予單位】：北京交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN929.1
本文編號：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.
【學位授予單位】：北京交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN929.1
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