Ergodic capacity analysis and asymptotic tightness for multi-element antenna array with spatial correlation and transmit water-filling

The authors analyse ergodic capacity for a system employing multi-element antenna array at the transmitter and receiver side. The signal is assumed to have both line-of-sight and non-line-of-sight (NLOS) components characterised by Rician fading distribution. The presence of the cluster of scatterers which gives rise to NLOS components is modelled using Von Mises Fisher (VMF) distribution. The impact of spatial correlation on capacity is graphically presented using MATLAB. The effect of channel state information at the transmitter side is analysed and plotted. Uniform circular array (UCA), which has been proved to outperform uniform linear array, is used at both the transmitter and the receiver. Furthermore, the effect of the radiation pattern of a UCA on the received signal-to-noise ratio is also plotted. Closed-form expressions for asymptotic tightness and upper bound of the system incorporating VMF distribution are obtained and plotted.