基于无人机平台的无线图传数据链系统的均衡技术研究

发布时间：2018-04-16 01:36

本文选题：UAV + 无线图传数据链　；参考：《国防科学技术大学》2014年硕士论文

【摘要】：当前,社会信息化不断推进、通信结构日趋多元,现有的地面通信和卫星通信等技术手段已无法满足人们日益增长的需求,机载通信正逐步成为立体化信息系统的一种重要增补和支援。随着无线通信和多媒体技术在下一代UAV无线图传数据链系统中的集成,对系统容量和服务质量的需求正在不断提升。如何提高数据传输的有效性和可靠性、降低BER,已成为当前无线通信领域研究的热点。将MIMO技术与OFDM技术相结合,或将SC-FDE技术与SC-CPM技术相结合均可很好地满足上述需求。然而,在动态、多径条件下的频率选择性衰落信道中,ISI、ICI等因素对系统性能的影响非常严重,因此有效的均衡技术已成为基于UAV平台的无线图传数据链系统设计的关键。针对常规方法在恶劣通信环境下计算复杂度较大、功率效率和频谱效率较低等缺点,本文从MIMO-OFDM与SC-FDE SC-CPM两条技术路线出发,提出了新型、高效的基于UAV平台的无线图传数据链系统的均衡技术方案:一、通过分析MIMO-OFDM UAV无线图传数据链的系统模型,提出了一种球形均衡技术的内协同优化方案。通过在初始搜索半径、检测顺序以及枚举策略等方面进行多重优化,并支持相关参数的可配置,在一定程度上降低了系统的计算复杂度。二、在前述基础上,提出了一种球形均衡技术的外联合优化方案。该方案将微量子遗传算法嵌入球形均衡技术,兼并量子计算和遗传算法的优点。此外,通过将多维搜索归纳为单维搜索,避免了大量繁杂的矩阵运算,提高了检测效率。三、提出了一种低复杂度SC-FDE SC-CPM技术。该技术将SCCC技术与CPM技术相结合,有效消除了ISI和ICI,获得了比Turbo码更优异的性能;同时,在每个数据包中嵌入导频训练字序列,用于信道估计;引入M进制Laurent分解方法,以进行低复杂度MMSE频域均衡。四、通过权衡前述两条均衡技术路线在UAV无线图传数据链系统中应用的利弊,提出了一种基于SC-FDE SC-CPM的低复杂度UAV均衡器的软硬件协同设计与优化方案。该方案将SC-FDE技术与SC-CPM技术相结合,在抵抗多径效应的同时,提高频谱、功率利用率;此外,通过对均衡器在算法和体系结构两个方面进行协同设计与优化,并引入可配置的均衡系数,大幅降低了系统的计算复杂度,提高了检测效率与复杂环境适应能力。总体而言,本文的主要研究工作聚焦于UAV无线图传数据链系统均衡技术的软硬件协同设计与多重优化,对于我国UAV无线图传数据链系统均衡技术的发展和国内外相关领域的研究具有十分重要的借鉴意义与应用价值。
[Abstract]:At present, with the continuous development of social informatization and the increasing diversity of communication structure, the existing technical means such as terrestrial communications and satellite communications can no longer meet the increasing needs of people.Airborne communication is becoming an important supplement and support for three-dimensional information system.With the integration of wireless communication and multimedia technology in the next generation UAV wireless graphic data link system, the demand for system capacity and quality of service is increasing.How to improve the efficiency and reliability of data transmission and reduce Bert has become a hot topic in the field of wireless communication.The combination of MIMO technology and OFDM technology, or SC-FDE technology and SC-CPM technology can well meet the above requirements.However, in frequency selective fading channels under dynamic and multipath conditions, such factors as ISI ICI have a very serious impact on the system performance. Therefore, effective equalization technology has become the key to the design of wireless graphic data link system based on UAV platform.In view of the disadvantages of the conventional method in the bad communication environment, such as high computational complexity, low power efficiency and spectrum efficiency, this paper proposes a new type of method based on the two technical routes of MIMO-OFDM and SC-FDE SC-CPM.An efficient equalization scheme for wireless graphic data link system based on UAV platform is presented. Firstly, by analyzing the system model of MIMO-OFDM UAV wireless graphic data link, a spherical equalization scheme is proposed.By optimizing the initial search radius, detection sequence and enumeration strategy, and supporting the configuration of the related parameters, the computational complexity of the system is reduced to a certain extent.Secondly, on the basis of the above mentioned, a scheme of external joint optimization of spherical equalization technique is proposed.The scheme embed the microelement genetic algorithm into the spherical equalization technique, merging the advantages of quantum computation and genetic algorithm.In addition, the multi-dimensional search is reduced to one-dimensional search, which avoids a large number of complicated matrix operations and improves the detection efficiency.Thirdly, a low complexity SC-FDE SC-CPM technique is proposed.This technique combines SCCC technology with CPM technology, effectively eliminates ISI and ICI, and achieves better performance than Turbo code. At the same time, pilot training word sequences are embedded in each packet for channel estimation. M-ary Laurent decomposition method is introduced.In order to achieve low complexity MMSE frequency domain equalization.Fourthly, by weighing the advantages and disadvantages of the above two equalization techniques in UAV wireless graphic data link system, a hardware / software co-design and optimization scheme of low complexity UAV equalizer based on SC-FDE SC-CPM is proposed.The scheme combines SC-FDE technology with SC-CPM technology to improve spectrum and power efficiency while resisting multipath effect. In addition, the equalizer is designed and optimized in two aspects: algorithm and architecture.By introducing configurable equilibrium coefficient, the computational complexity of the system is greatly reduced, and the detection efficiency and adaptability of complex environment are improved.In general, the main work of this paper focuses on the hardware / software co-design and multiple optimization of the equalization technology of UAV wireless graphic data link system.It has very important reference significance and application value for the development of equalization technology of UAV wireless graphic data link system and the research of related fields at home and abroad.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：V279;TN919.3

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