Relay Channel Modeling Under 3D Environment

With the rapid expansion of mobile multi-media services,high-speed transmission of large data on existing wireless communication network presents a challenge.By deploying 3-Dimensional antennas in cells and utilizing advantages of the 3D MIMO and relay technologies,people can further enhance the transmission capability of the relay systems.However,some shortcomings of the research on 3D relay channel modeling have been pointed out publicly.Thus,this thesis will focus on the relay channel propagation characteristics and modeling of fixed relay backhaul link under 3D environment based on channel measurements and theoretical analysis.The main work of this thesis includes three points:(1)The extraction and analysis of correlation characteristics of 3D relay channel from measurement data.With the methods of 3GPP TR36.873,this thesis has extracted channel model parameters and analyzed the correlation characteristics from the relay channel measurements in 3D environment.All of these are aimed to investigate the effects of different scatterers distribution and velocity on relay channel propagation.Measurement results show that there are some distinct differences,which are caused by the relay's mobility and antenna height,between the relay backhaul link and the traditional direct link.(2)The modeling of the 3D relay channel based on moving scatterers.In fixed wireless communications,the received signals would still experience time variation because moving scatterers around the antennas bring Doppler shifts to the signals.And the higher radio communication frequency is,the more obvious this phenomenon is.According to this fact and the measurement results,this thesis has proposed a 3D model for fixed MIMO relay channel based on moving scatterers.The influence of different scatterers distribution and velocity on relay backhaul link channel correlation characteristics has also been simulated and validated.(3)The modeling of 3D relay complex fading channel.Based on the space-time correlation channel modeling method,this thesis has studied the modeling of 3D relay complex fading channel,which combines the multipath fading and shadow fading.On one hand,the channel correlation function is derived theoretically from the Generalized-K fading distribution,and the effects of different fading depth on time autocorrelation are also investigated.On the other hand,the channel spatial correlation function is obtained from the antenna power angle spectrum.In this way,this thesis has completed the modeling and simulation of the 3D relay complex fading channel.In according with the measurements and theoretical model,this thesis has studied the effects of different scatterers distribution and velocity on relay backhaul channel correlation characteristics,both qualitatively and quantitatively.And a more widely used 3D relay channel model,which is suitable for the complex fading,is also proposed in this thesis.