Analysis of 2-user ZF coordinated with user-wise MRTC diversity

Abstract

Multi-user MIMO and spatial diversity are attractive techniques to improve the link capacity. In this paper, multi-user zero-forcing (ZF) coordinated with user-wise maximal-ratio transmitting and combining (MRTC) diversity is studied. A closed-form expression for the received signal-to-noise ratios (SNRs) achievable with 2-user ZF coordinated with user-wise MRTC diversity is derived for the given MIMO channel condition. It is shown from the derived SNR expression that the uplink capacity is higher than the downlink capacity and that the uplink capacity is not necessarily the same among users while the downlink SNR is always identical for users. This is confirmed by numerical evaluation assuming a Rayleigh fading environment.

Zero-forcing based multi-user MIMO coordinated with user-wise joint transmit-receive diversity

“…Recently, we studied ZF-based multi-user MIMO coordinated with user-wise maximal-ratio transmitting and combining diversity (MRTCD) assuming timedivision duplex (TDD) downlink and uplink transmissions [6]. In this paper, we extend our previous study and propose user-wise joint transmit-receive diversity (JTRD) for ZF-based multi-user MIMO.…”