Land Mobile Fading Channel The Physical Statistical Modeling Study

In2012, TD-LTE-Advanced, the standard of fourth generation mobile communication systems proposed by China, has accepted by the International Telecommunication Union. After that, the4G development of our country has a standard to follow. In4G communication system, the bandwidth of the system is100MHz. The peak data rate is1Gbps in uplink and500Mbps in downlink. This is a greater challenge for the transmission rate of the system.With the increasing requirements of transmission rate, the wireless transmission channel becomes more unstable. This is because the wireless transmission channel is a complex multi-path fading channel. The multi-path signals, experienced different length of the propagation path, will reach the receiver in different time. For the phase of multi-path signal in receiver is different, the strength of receiver signal may be enhanced or diminished via superimposing, which leads the rapid fading of the signal in a short distance. Therefore, studying the characteristics of radio channel and accurately modeling the channel is important. Recently, there are two methods of channel modeling, statistical models and deterministic models. Owing their respective advantages, the two methods have been got concern of many researchers, while seeking the advantages of the two methods for modeling has also been popular.Based on the advantage of physical-statistical model, the paper models for land mobile fading channel using this method, and applies in the MIMO systems. The focus of this work is as follows:Fisrtly, the paper establishes two novel physical-statistical models, which combine Nakagammi and R models with the method of ray-tracing. In the physical-statistical model, what physical parameters of propagation environment influence on the signal transmission is considered, such as building height, street width and azimuth angles. With the method of ray-tracing, we trace the statistical parameters varying with those physical parameters and deduce first-order fading distribution. Then one physical-statistical model is applied to a MIMO communication system which is a double antennas transceiver system.Secondly, the work also simulates the physical-statistical models and analyses statistical properties. The process of the simulation includes tracking the parameters of statistical model and giving statistical characteristic curves. The former is also the process of ray-tracing. The work of ray-tracing in the MATLAB simulation platform contains giving ray-tracing method using flow charts, and explaining sampling principle in small scale fading case, and tracing rays undergoing straight line, reflection and diffraction. Then we can plot small scale fading curves in which statistical parameters can obtained. The latter is getting first-order fading distribution with the statistical parameters, and providing first-order fading distribution. Through simulation for physical-statistical model, we can see that the mixed model is an accurate method for wireless channel, and statistical properties with formula can be derived.