无线通信信道仿真及预测

Simulation and Prediction of Wireless Communication Channel

随着无线通信不断发展,对无线通信信道仿真需求逐渐增加,为了解决无线通信信道仿真局限性低,准确度差等问题,采用硬软结合的无线通信信道仿真系统,使其具有适用性强,人机交互性好等特点。整体上将信号的传播损耗分为大尺度衰落和小尺度衰落。对于大尺度衰落采用晴空模型;使用多径预测模型模拟小尺度衰落。硬件部分采用FPGA(Field Programmable Gata Array)和DSP(Digital Signal Processing)搭建系统计算损耗。对于晴空模型使用FPGA计算视距传播、衍射、对流层、大气波导层和附加基本损耗;多径仿真模型使用FPGA+DSP的形式搭建抽头时延先的仿真系统。软件部分使用Qt编写上位机可视化界面,提供了用户输入入口和结果显示,并使用串口通信的方式传输模型的设定参数以及输出结果。经过实验测试和真实数据对比,系统能够较好地仿真不同环境下的无线信道,从而可以提高信道仿真的便捷性,并减小成本。

With the continuous development of wireless communication, the demand for wireless communication channel simulation is gradually increasing. In order to solve the problems of low limitation and poor accuracy of wireless communication channel simulation, a wireless communication channel simulation system is designed by combining hardware and software. The propagation loss of signal can be divided into large scale fading and small scale fading. Clear sky model is used for large-scale fading. Small-scale fading is simulated by multipath prediction model. The hardware part of the simulation system uses FPGAA(Field Programmable Gata Array) and DSP(Digital Signal Processing) to build the system so as to calculate the loss. For the clear-sky model, FPGA is used to calculate the line-of sight propagation loss, diffraction loss, tropospheric loss, atmospheric waveguide layer loss and additional basic loss. In multi-path simulation model FPGA+DSP is used to build the tap delay first simulation system. Qt is used to write visual interface of the upper computer, providing the user input entry and the result display, and using the serial communication way to transmit the model set parameters and output results. After testing and adjusting the simulation system, we finally can better simulate the wireless channel under different environments, so as to improve the convenience of channel simulation and reduce the cost.