基于传输线的无线信道多径实验模块

无线通信中信道环境复杂,存在多径效应,使传输信号受到符号间干扰,引起失真,严重影响通信系统的性能。为了模拟多径信道,分析了射频电路里的传输线。传输线与无线信道的特征阻抗都恒定不变,信号路径数量可变,传播的信号相位都呈现周期性变化,传播延迟与距离呈线性关系。在每条传输线中增加可变电阻模拟信号在自由空间的衰减,采用微波电路实现无线通信实验中的多径模块,模拟无线信道的多径效应。多径模块可与发射机和接收机构成一个完整的无线通信系统实验平台。

Multipath experiment module in wireless channel based on transmission line

n wireless communication,the channel environment is complex and there is multipath effect,which makes the transmission signal suffer from inter symbol interference and distortion,seriously affecting the performance of communication system.In order to simulate the multipath channel,the transmission line in RF circuit is analyzed.The characteristic impedances of transmission lines and wireless channels are constant,the number of signal paths is variable,the phase of the transmitted signal changes periodically,and the propagation delay is linear with the distance.In each transmission line,the attenuation of analog signal with variable resistance in free space is added,and the multipath module in wireless communication experiment is realized by using microwave circuit to simulate the multipath effect of wireless channel.The multipath module can form a complete wireless communication system experiment platform with the transmitter and receiver.