Opportunistic Scheduling and Beamforming for MIMO-SDMA Downlink Systems with Linear Combining

TL;DR

This paper introduces opportunistic scheduling and beamforming techniques for multiuser MIMO-SDMA downlink systems that use linear combining to enhance effective SINRs, leading to significant throughput improvements.

Contribution

It proposes new scheduling and beamforming schemes utilizing linear combining and derives their asymptotic throughput and scaling laws using extreme value theory.

Findings

Significant throughput gains demonstrated through simulations

Asymptotic throughput scaling laws derived for the proposed schemes

Linear combining improves effective SINRs and system performance

Abstract

Opportunistic scheduling and beamforming schemes are proposed for multiuser MIMO-SDMA downlink systems with linear combining in this work. Signals received from all antennas of each mobile terminal (MT) are linearly combined to improve the {\em effective} signal-to-noise-interference ratios (SINRs). By exploiting limited feedback on the effective SINRs, the base station (BS) schedules simultaneous data transmission on multiple beams to the MTs with the largest effective SINRs. Utilizing the extreme value theory, we derive the asymptotic system throughputs and scaling laws for the proposed scheduling and beamforming schemes with different linear combining techniques. Computer simulations confirm that the proposed schemes can substantially improve the system throughput.