Abstract— In this paper, we present the closed-form expressions for the link outage and coverage of the zero-forcing beamforming (ZFB) and zero-forcing dirty-paper coding (ZF-DPC) multiuser multi-input multi-output (MIMO) broadcast systems. We find that the ZF-DPC MIMO broadcast system has a larger diversity order and better coverage compared with the ZFB MIMO broadcast system. Furthermore, it is observed that the ZFB MIMO broadcast system with round-robin scheduling has only the diversity order of one and its cell coverage can only approach to that of the weakest link of the ZF-DPC MIMO broadcast system. By selecting the best group of users, multiuser scheduling can function as a soft coverage enhancement technique without increasing the extra transmission power in the physical layer. Our analytical formula can estimate to what extent the coverage performance of the ZF-DPC MIMO broadcast system can be improved as the number of users increases. Hence, the effect of increasing the number of antennas on the coverage performance of the ZF-DPC MIMO broadcast system can be quantitatively analyzed subject to the same transmission power from each base station.

Index Terms— MIMO systems, zero-forcing beam-forming, zero-forcing dirty-paper coding, coverage, MIMO broadcast channels, outage probability, diver¬sity order.

Cite:Li-Chun Wang and Chu-Jung Yeh, "Coverage Analysis for Multiuser MIMO Broadcast Systems," Journal of Communications, vol. 6, no.4, pp.293-300, 2011. Doi: 10.4304/jcm.6.4.293-300