非视距环境下COFDM系统传输模式的适应性研究

摘要

Coded Orthogonal Frequency Division Multiplexing ( COFDM) technology is widely used in image transmission for dig⁃ital video broadcasting,forest fire prevention and urban road monitoring.These applications are mainly urban and mountainous areas.Dif⁃ferent NLOS environments have different propagation characteristics.Appropriate COFDM system parameters are chosen to adapt channel characteristics accordingly.MATLAB software is used to build COST207 NLOS channel emulation platform for a variety of transmission parameter mode simulation and performance analysis. Bit error rate and spectral efficiency are evaluated to determine the requirement meeting system parameters,so that different NLOS inter⁃channel environments and different systems achieve the best transmission mode adaptation effect.Simulation results show that different channel environments and different transport modes to achieve a good adaptation, reaching the design requirement.%编码正交频分复用（ Coded Orthogonal Frequency⁃Division Multiplexing， COFDM）技术在数字视频广播、森林防火和城市的道路监控等图像传输领域的应用越来越广泛，这些应用环境主要是城区和山区。不同的非视距环境具有不同的传播特性，因此需要选择合适的COFDM系统参数来适应相应信道特性。采用MATLAB软件搭建COST207非视距信道仿真平台，对多种传输参数模式进行仿真和性能分析，通过对误码率和频谱利用率的评估，确定满足要求的系统参数，从而使不同的非视距信道环境和不同系统传输模式间达到最佳的适配效果。仿真结果表明，不同的信道环境和不同的传输模式达到了很好的适配，达到了设计的要求。