Radio Channel Simulating And Modeling

The research on simulation model of radio channel has developed for a long time, but most of them only consider Small Scale Fading. While, for the research of Cognitive Radio, the most basic task is to resolve the signal apperception through air interface, while not only solve the influence of Small Scale Fading on data transfer technology. Cognitive Radio also need to estimate whether the accessing of un-licensed subscribers bring interference to licensed network and its subscribers and the grade of that interference. As thus, Cognitive Radio is able to give a mechanism of the intellectualized login and logout for un-licensed subscribers. It will also give a judge and calculate method for the threshold value of login and logout. So, in this paper, Large Scale Fading and Small Scale Fading are both considered in the research of simulation model of radio channel.Firstly, this paper reviews the history of personal mobile communication about forty years since it came into business. Then recommends the status quo of research on simulation of radio channel and analyses the basic performance of radio channel fading from the point of view of Small Scale Fading and Large Scale Fading.Secondly, this paper introduces the Rayleigh Flat Fading Channel Model and its reference model——Clarke Model. And it compares the simulation model of Rayleigh Flat Fading Channel Model which bases on traditional Jakes emulator with an improved Rayleigh Flat Fading Channel Model. Then it select the latter as the simulation model of single path Rayleigh Fading Channel and adds different stochastic delays to five single Rayleigh Fading Channels to generate the Frequency-Selective Fading Channel with the LOS(Light of Sight) embranchment. This paper doesn't adopt the Suzuki Model which is common used to simulate Large Scale Fading, but loads path loss on Rayleigh Fading Channel and LOS spur track with COST231-Hata Model. Thus, the distance between transmitter and receiver can be used in the simulation model of radio channel. So that, the simulation system can emulate different network coverage modes and user situations to help to the qualitative and quantitative research of Cognitive Radio.