Simulation And Analysis Of Channel Model Based On802.11Standard

In modern society, the mobile communications is rapidly developing. Therefore, the demand for the channel bandwidth, capacity, and the quality of the communication system are also increasing dramatically. However, one of the key techniques which can cope with these requirements is MIMO (Multiple-Input and Multiple-Out) technique. MIMO is a diversity utilization that can improve the communication quality, realize higher data rates, and increase system capacity. So MIMO has a broad prospect of application, and it is a significant technique that will be studied in the future for the high-speed mobile communications system.In the MIMO system, if the correlation coefficient between two receiving antennas is very small, the capacity of resisting fading will improved greatly. As a result, the capacity of the system will increase. However, due to limited spacing between the antennas, so there must be a certain correlation between the received signals from various quarters. Therefore, in order to better study MIMO techniques and evaluate the performance of MIMO system, it is necessary to study the characteristics of MIMO channel, and establish different channel models for different scenes.First, this thesis describes the development of broadband wireless channel models and some problems to be solved. It also analyzes the characteristics of the wireless fading channel, such as large-scale fading and small-scale fading; then describes their envelope characteristics. In this chapter, the characteristics of small-scale fading are discussed in detail.Secondly, this thesis presents the basic theoretical knowledge for broadband wireless channel model and describes the classification of modeling methods, the key parameters of models, and the typical methods of channel modeling. The spatial correlation of the MIMO channel is discussed in detail. We describe the definition of correlation. Then, based on three distributions (uniform distribution, Gaussian distribution and Laplace distribution) of Power Azimuth Spectrum, we give different calculation methods of correlation coefficients. The simulation result shows that the spacing between two antennas, AOA(Angle Of Arrival), AOD(Angle Of Departure), AS(Angular Spread), and PAS(Power Azimuth Spectrum) will influence the correlation coefficient between two antennas.Finally, this thesis describes the parameters of TGn channel model, and gives a detail simulation flow. The characteristics of channel model, including time-domain response, the cumulative distribution functions (CDF), power delay profile (PDP), Doppler shift and correlations, are analyzed and verified. Then we apply this MIMO channel model to system simulation, comparing the PER performance under different antenna configurations and different channel models. Then, considering the high-speed channel modeling environment, establish channel model based on the above study, simulate its channel characteristics to verify the rationality of the model.