Multiuser Switched Diversity Scheduling Schemes

TL;DR

This paper analyzes multiuser switched-diversity scheduling schemes that reduce feedback requirements with minimal loss in capacity, introduces a proportional fair scheme, and demonstrates near-optimal performance in Rayleigh fading environments.

Contribution

It characterizes the rate region of switched-diversity systems, proposes a distributed optimization method for fairness, and shows these schemes perform close to full feedback systems.

Findings

Operates within 0.3 bits/sec/Hz of full feedback capacity in Rayleigh fading.

Provides a practical distributed method for threshold optimization.

Characterizes the achievable rate region of switched-diversity systems.

Abstract

Multiuser switched-diversity scheduling schemes were recently proposed in order to overcome the heavy feedback requirements of conventional opportunistic scheduling schemes by applying a threshold-based, distributed, and ordered scheduling mechanism. The main idea behind these schemes is that slight reduction in the prospected multiuser diversity gains is an acceptable trade-off for great savings in terms of required channel-state-information feedback messages. In this work, we characterize the achievable rate region of multiuser switched diversity systems and compare it with the rate region of full feedback multiuser diversity systems. We propose also a novel proportional fair multiuser switched-based scheduling scheme and we demonstrate that it can be optimized using a practical and distributed method to obtain the feedback thresholds. We finally demonstrate by numerical examples that switched-diversity scheduling schemes operate within 0.3 bits/sec/Hz from the ultimate network capacity of full feedback systems in Rayleigh fading conditions.