Study of LB-SE with Perfect CSI in Hyper MIMO

Analytical consideration of lower bound (LB) analysis of the spectral efficiency (SE) of downlink transmission of Hyper MIMO (H-MIMO) system is important to obtain insights in the role of various factors that are involved. In this paper, we derived a mathematical expression for lower bound of the SE of an H-MIMO system with linear precoding techniques such as zero-forcing (ZF) and minimum mean square error (MMSE). The analysis of SE considers three joint user and antenna scheduling algorithms such as semi-orthogonal, random, and distance based user scheduling algorithms, whereas the antennas are selected based on maximum SNR with scheduled users. The channel between a user and a transmitter is assumed to have characteristics of small and large scale fading (SSF and LSF) with Rayleigh distributed block fading model. We investigate the effect of variation of transmit power, number of base station antennas M , and the radius of the cell on the SE. We simulate the downlink transmission of H-MIMO system and compare the simulation and analytical results. It is observed that the trends of variation of both results with the variation of different factors are similar, and the difference between the simulated and analytical LB-SE is approximately 1–1.5 bits. In this case the analytical LB is the smaller of the two.