Based On The Geometry Of The Mimo Mobile-to-mobile (m2m) Fading Channel Modeling

Mobile-to-Mobile (M2M) communication system is a kind of mobile communication system which is not depending on the fixed base station. Recently, M2M communications have received much attention due to its good performance and several emerging applications, such as wireless mobile ad hoc networks, relay-based cellular networks, and dedicated short range communications (DSRC) for intelligent transportation systems (e.g., IEEE 802.11p standard). And the MIMO technology can overcome the fading effect effectively, and to provide higher capacity and higher spectrum efficiency through the space diversity.The M2M systems using MIMO technology, which can improve the MIMO M2M channel capacity, system quality of service, increase the transmission power and bandwidth, reduce the bit error rate, and improve the M2M system performance greatly. Furthermore, understanding the characteristics of the MIMO M2M channel contribute to design the communication systems with ideal performace. However, the exist channel model could not be used to describe the propagation properties of the M2M fading channels, meanwhile, there are not sufficient research results could be used to explain the space-time-frequency characteristics of M2M channels. So, the MIMO M2M channel modeling and a good understanding of the space properties of MIMO M2M channel for studying M2M communication systems is very necessary.So, we focus on the research of MIMO M2M fading channel modeling, by utilizing the computer simulations method, modeling the M2M channel model and analyzing the statistical properties of the channel, in order to build new MIMO M2M channel model for real wireless propagation environment and study the space-time-frequency statistical characteristics for fading channel combining with the MIMO technology. The focus of this paper is MIMO M2M channel modeling, including as follows:Firstly, for the frequency non-selective Rician fading MIMO M2M channel, we provide a geometrical triple-ring scatters distribution model based on relay cooperative communications. In this channel model, we use the method of channel modeling based on geometrical scatters model, and combined with existing channel model. Then, we derived the auto-correlation function, the space-time cross-correlation function and the Doppler Power Spectral Density of the scatters component and the LOS component respectively, and also give an analysis and simulation to the auto-correlation function in time domain, the cross-correlation function in space domain,and then the capacities of various channel models obtained by different capacity expression (e.g. the formula derived from traditional uniform-correlation antenna matrix and the modified exponent-correlation antenna matrix) are simulated and compared. By comparison, the simulation results show that the geometrical triple-ring MIMO M2M channel model has strong applicability, and can reflects that the spacing of the antennas, the angle-of-arrival, the angle-of-departure and other factors how to affect the correlation of the MIMO M2M channel model.Secondly, the model is extended to the frequency-selective fading channel by considering the clusters of the scatterers. And, this wideband channel model not only takes into account both transmitter's and receiver's mobiling and the LOS component exsiting in frequency selective Rician MIMO M2M channel, but also consider that the frequency how to affect the channel's correlations. And then, the space-time-frequency Cross-Correlation function, the Power Delay Profile and the Doppler Power Spectral Density of the wideband MIMO M2M channel model are derived. Meanwhile, we discuss that the various factors including the spacing of the antennas, AOA, AOD, spread factor, the velocity of moving and so on how to affect the correlation between the channel and the channel capacity, then, some simulations and analysis are obtained.Finally, the proposed geometric triple-ring model of MIMO M2M fading channel is validated by using the measured data. And, the results show that the proposed channel models with the experimental results are in good agreement.