航空信道建模与仿真

发布时间：2019-02-11 15:08

【摘要】：航空通信信道是指飞机与地面塔台之间的无线传播信道。随着航空无线业务的发展,对新一代航空无线通信系统的研究开发越来越迫切。为了支撑新一代航空无线通信系统的研发,有必要对航空信道的特性进行深入研究,并构建航空信道仿真模型。本文第二章通过总结现有的文献,将航空信道分为包括停泊、滑行、起飞/降落、巡航和飞过塔台在内的五个场景,并给出了每种场景下航空信道的延时功率谱和多普勒功率谱,建立了多场景航空信道的参考模型。为了建立航空衰落信道的宽带统计模型——抽头延迟线模型,同时给出了谐波叠加法和多普勒滤波法对信道的延时功率谱、多普勒功率谱建模。当仿真时间受限时,谐波叠加模型的样本函数并不能遍历随机模型的统计特性,因此谐波叠加模型的仿真需求时间要求充分长,增加了模型的时间复杂度。为此,本文第三章提出了一种改进的谐波叠加仿真方法,使用等距离法构建模型,并将仿真时间设置为模型时限时间相关偏差函数的一系列局部极小值点附近的值。针对航空信道的分析和仿真表明,在保证模型时限时间相关性能的前提下,该方法可极大地降低仿真需求时间。此外,当采用基于FFT的多普勒滤波法仿真多普勒功率谱时,若多普勒功率谱为窄带谱,多普勒滤波器的阶数会非常高,导致多普勒滤波模型的复杂度极高。为此,本文第四章提出了一种改进的FFT多普勒滤波法,先针对频移的多普勒功率谱构建滤波器,再对多普勒滤波器的输出在时域补偿频偏。针对航空信道的分析和仿真表明,在保证模型统计特性性能的前提下,该方法可将滤波器的阶数降低到一个合理的程度,从而极大的降低仿真模型的计算复杂度。本文第五章基于Matlab构建了多场景宽带航空信道仿真模块,仿真模块可灵活地配置信道参数,方便航空无线通信系统链路的使用。性能测试表明,仿真模块具有优良的时限时间相关特性和频率相关特性。最后,论文基于EB F8信道仿真器搭建了半实物射频航空信道仿真平台。测试结果表明,所搭建的多场景宽带航空信道仿真模型在射频段具有优良的统计特性性能。最后本文第六章给出了全文的总结和下一步的研究建议。
[Abstract]:Aeronautical communication channel refers to the wireless transmission channel between aircraft and ground tower. With the development of aviation wireless service, the research and development of new generation aviation wireless communication system is becoming more and more urgent. In order to support the research and development of the new generation aviation wireless communication system, it is necessary to study the characteristics of the aviation channel and construct the simulation model of the aviation channel. In the second chapter, by summarizing the existing literature, the aviation channel is divided into five scenarios, including berthing, taxiing, take-off / landing, cruise and flying over the tower. The delay power spectrum and Doppler power spectrum of the aeronautical channel in each scenario are given, and the reference model of the multi-scene aviation channel is established. In order to establish the wideband statistical model of aeronautical fading channel, a tap delay line model is established, and the delay power spectrum and Doppler power spectrum model of the channel by harmonic superposition method and Doppler filter method are presented. When the simulation time is limited, the sample function of the harmonic superposition model can not traverse the statistical characteristics of the stochastic model, so the simulation time requirement of the harmonic superposition model is long enough, which increases the time complexity of the model. In the third chapter, an improved method of harmonic superposition simulation is proposed. The model is constructed by using the equidistance method, and the simulation time is set to the value near a series of local minimum points of the time-dependent deviation function of the model. The analysis and simulation of the aeronautical channel show that the proposed method can greatly reduce the simulation time under the premise of ensuring the time-dependent performance of the model. In addition, when the Doppler power spectrum is simulated by Doppler filter based on FFT, if the Doppler power spectrum is narrow band spectrum, the order of Doppler filter will be very high, which leads to the extremely high complexity of Doppler filter model. In the fourth chapter, an improved FFT Doppler filter is proposed. Firstly, the filter is constructed for the frequency shift Doppler power spectrum, and then the output of the Doppler filter is compensated in the time domain. The analysis and simulation of the aeronautical channel show that the order of the filter can be reduced to a reasonable degree under the premise of ensuring the statistical performance of the model, thus greatly reducing the computational complexity of the simulation model. In the fifth chapter, we construct a multi-scene broadband aviation channel simulation module based on Matlab. The simulation module can flexibly configure the channel parameters and facilitate the use of the aviation wireless communication system link. The performance test shows that the simulation module has excellent time-dependent and frequency-dependent characteristics. Finally, based on the EB F 8 channel simulator, a hardware-in-the-loop radio frequency channel simulation platform is built. The test results show that the multi-scene wideband aviation channel simulation model has good statistical performance in RF segment. Finally, the sixth chapter of this paper gives the full text of the summary and the next step of the research recommendations.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：V243;TN92

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