| In order to design high performance multiple-input multiple-output (MIMO) wireless systems, and to predict the impact of random multipath propagation for Rayleigh fading, it is necessary to have accurate and reliable MIMO channel models. Using the assumption of plane wave propagation, in this dissertation we derive cross-correlation functions (CCF)s between the space-time-frequency (STF) transfer functions of two sub-channels of an outdoor radio propagation channel for different scenarios.; Most MIMO-CCF models employ a certain geometry for scatterers around mobile station (MS) to describe the non-isotropic propagation. Alternatively in this dissertation, we employ the relationship between the channel gain and the time-delay rather than the geometry of scatterers, and derive the CCFs for the following four scenarios: (1) 2D isotropic propagation environment employing omnidirectional array antennas, when the MS moves with a constant linear speed [23, 60, 62], (2) 2D non-isotropic propagation environment employing non-omnidirectional array antennas, when the MS moves with a constant linear speed [58, 64], (3) 2D non-isotropic propagation environment employing non-omnidirectional array antennas, when the MS rotates with a constant angular velocity [57, 61, 65], (4) 3D non-isotropic propagation environment employing non-omnidirectional array antennas, when the MS moves with a constant linear speed [59, 63, 66, 67]. In all cases, the proposed CCF is expressed in terms of several distribution parameters of the propagation environment, and is a summation of two terms: (a) the first term is due to the auto-correlation of multipath components and, (b) the second term is due to the cross-correlation of multipath components. Each term is a product of several correlation functions. These correlation functions represent the impact of the wireless channel (1) around the transmitter, (2) around the receiver, and (3) along the channel, in terms of time, carrier frequency, or position of the antenna elements. The impact of propagation along the channel is described by the moment generating function of the delay profile, the path-loss exponent, and the distance between carrier frequencies. The impacts of propagation around either the BS or the MS are described by the associated separation vectors. In order to see the effect of the propagation environment, the employed antennas, and the motion of the MS on the CCF, the expression of the channel power spectrum is calculated in the frequency domain and is numerically evaluated under specific circumstances. The coherence bandwidth and the coherence time are respectively calculated and analyzed as a function of the carrier frequency and the time-difference index. |
