直升机卫星通信采用分集合并技术提高性能

发布时间：2021-06-24 11:11

　　直升机在自然灾害、紧急救援和军事侦察等场景都有十分显著的应用,在这些场景下大多数其他系统通常都已经失效,此外,直升机也可以比较容易提供运输和支援作用。在自然灾害和敌军破坏等情况下通信网络可能已经失效,若由于这些破坏而失去通信能力,直升机也就失去了其利用价值。而直升机卫星通信可以稳定提供有效可靠的高速通信,因此直升机的重要利用价值和其对通信的需求推动了人们对直升机卫星通信的研究。直升机卫星通信研究的核心论文内容主要包括直升机旋翼遮挡模型、采用时分复用的沃什-哈达玛编码。本文首先研究了直升机卫星通信信道的属性和特点,然后基于一些成熟的信道模型提出了带旋翼遮挡的衰减信道模型。在MATLAB仿真中都采用了这个信道模型,并且也使用了针对其他问题的技术。致力于提高直升机卫星通信性能,本文首先研究了采用码分复用的沃什-哈达玛变换的系统。然后该系统采用精确的双重时间分集来减少码间干扰并改善了系统。本文中也这些系统模型进行了仿真和分析。更进一步地,前面提到的系统模型在其接收端通过分集合并得到改进和提升。分集合并方案已经被证明为是解决旋翼遮挡问题的最优方案并且提升了其传输速率。本文也对包括双重时间分集合并... 

【文章来源】：电子科技大学四川省 211工程院校 985工程院校 教育部直属院校

【文章页数】：79 页

【学位级别】：硕士

【文章目录】：
摘要
abstract
Chapter 1 Introduction
    1.1 Research Background and Significance
        1.1.1Advancement of Satellite Communication system
        1.1.2 Significance of Helicopter in Communication
        1.1.3 Problems in Helicopter Satellite Communication System
    1.2 State of the art
        1.2.1 International Research Status
        1.2.2 Chinese Research Status
    1.3 Contents and Innovations of the Thesis
    1.4 Outline of the Thesis
Chapter 2 Theoretical Basics
    2.1 Introduction
    2.2 Helicopter Satellite Communication Channel Characteristics
        2.2.1 Free Space Transmission Loss
        2.2.2 Additional Link Loss
        2.2.3 Multipath Fading
        2.2.4 Shadowing decay
        2.2.5 Helicopter Rotor Shelter model
    2.3 Channel Analysis based on Experimental data and Statistics
        2.3.1 Channel Measurement Method Analysis
        2.3.2 Qualitative analysis of channel measurement results
    2.4 Basic Helicopter Satellite Communication Channel Model
        2.4.1 Simplified Channel
    2.5 Walsh Hadamard Transform
        2.5.1 Construction of Walsh Codes
    2.6 Conclusion
Chapter 3 Diversity Combining Schemes
    3.1 Introduction
    3.2 Concept of Diversity
    3.3 Types of Diversity
        3.3.1 Frequency Diversity
        3.3.2 Time Diversity
        3.3.3 Space Diversity
    3.4 Diversity Combining Schemes
        3.4.1 Selection Combining (SC)
        3.4.2 Maximal Ratio Combining (MRC)
        3.4.3 Equal Gain combining (EGC)
    3.5 Performance Analysis of Diversity Combining Schemes
        3.5.1 BER performance of MRC and EGC with Nakagami m-Channel
    3.6 Conclusion
Chapter 4 Modelling and Simulation of Diversity combining schemes in system ..
    4.1 Introduction
    4.2 Performance of WHCDM with time diversity:
    4.3 Performance of System with WHCDM and Time Diversity
        4.3.1 Simple WHCDM Implementation in System:
        4.3.2 WHCDM implementation with Time Diversity in system
    4.4 Performance of WHCDM with Equal Gain Combining
        4.4.1 Transmitter for EGC and MRC schemes implementation
        4.4.2 Receiver for WHCDM with equal gain combining
    4.5 Performance of WHCDM with Maximal Ratio Combining:
        4.5.1 Receiver for WHCDM with Maximal Ratio Combining:
        4.5.2 Pseudo BER calculator
    4.6 Conclusion
Chapter 5 Conclusions
    5.1 Concluding Remarks
    5.2 Future Work
Acknowledgements
References


【参考文献】：
期刊论文
[1]直升机卫星通信的前向链路设计[J]. 张倨卿,高凯,朱江.  无线电通信技术. 2012(05)
[2]适用于直升机卫星通信的LDPC译码算法[J]. 王健,胡应鹏,司飞飞.  通信技术. 2012(09)



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