Doppler spectrum and second order fading statistics of emerging 3-D radio cellular propagation channels

In implementing fifth generation (5G) networks, the advancements in density of networks, cell size, scale of antenna arrays, communicating nodes mobility, and range of frequencies necessitate to derive a reliable and appropriate channel model. A geometric three dimensional (3-D) tunable channel model is proposed with high degree of flexibility in modelling the orientation, shape, and scale of the scattering region and comprehending the mobility of user terminal. Characterization of second order fading statistics and Doppler spectrum of the radio propagation channel is presented. Mathematical expressions for probability density function (PDF) of Doppler shift and multipath power are derived. The impact of various physical (geometric) channel parameters on statistical characteristics of Doppler spectrum and second order fading statistics is thoroughly analyzed.