MPSK信号在多径衰落信道中传输特性的研究与仿真

The Research and Simulation of the Translated-characteristic MPSK Signal in the Multipath Fading Channels

多径衰落是指沿不同路径传送的信号会有不同的衰减与延时,在接受天线处以相互增强或抑制的方式叠加在一起。多径衰落通过两种方式影响信号:扩散特性(时间扩展或频率选择)和时变特性。本文采用抽头延时线模型的抽头增益过程来仿真多径效应,通过研究散射函数、多径强度曲线、多普勒频率谱及多普勒带宽等特性,进而掌握时变多径信道对MPSK信号传输的影响,对系统建模有明确的认识与评估。

Multipath fading means that the signals transiting through the different channels will have the different fading and delay, and then they splice together in the form of strengthening or weakening at the received antenna. There are two kinds of forms for multipath fading to affect signal: spread diffuse(time spread or frequency selective) and time variety. The model of tapped-delay line is used for simulating the multipath. Studying the kinds of characters of diffusing function, multipath intension curve, Doppler spectrum and Doppler bandwidth, we can know timing-variety multipath’s character and its influence for MPSK, and then have the good understanding and evaluation for the system modeling.