Energy-efficient multi-user resource management with IR-HARQ

A general energy-efficient multi-user management framework for incremental redundancy (IR) HARQ is proposed. We first develop a basic tradeoff between energy efficiency, power, bandwidth and delay of IR-HARQ, which reveals that frequency domain, rather than power domain, offers a larger space for exploiting energy efficiency with delay constraints. Based on the basic tradeoff, the proposed energy-efficient multi-user management framework, consisting of user scheduling and power/bandwidth allocation, optimizes energy efficiency (EE) in both power and frequency domain. It is shown that while achieving EE, power-domain optimization is more effective and provide higher throughput for large-bandwidth scenarios, and frequency-domain optimization produces shorter delay in small bandwidth scenarios.