Spectral efficiency of distributed MIMO systems with ZF receivers

Distributed multiple-input multiple-output (D-MIMO) is a promising technique for next generation wireless networks, which offers a remarkable spectral efficiency gain over the conventional co-located MIMO (C-MIMO) systems. In contrast to C-MIMO, which can be regarded as a special case of D-MIMO, performance analysis of D-MIMO is a challenging problem. This is because radio channels between a user and the distributed radio ports (RPs) are characterized by non-identical path-loss and shadowing effects which render the classical analytical methods non-tractable. In this paper, we consider the uplink spectral efficiency of a single-cell distributed MIMO (D-MIMO) system with linear zero-forcing (ZF) receivers. Without taking shadow fading effects into account, new accurate expressions for the average spectral efficiency for D-MIMO and C-MIMO systems are given and compared. These expressions provide meaningful insights into the impact of SNR, RPs and user positions, and number of RPs antennas on the spectral efficiency of the system under practical environments. Finally, numerical results are validated by simulation to confirm our analysis.