Energy-Efficient Scheduling and Power Allocation in Downlink OFDMA Networks with Base Station Coordination

TL;DR

This paper investigates energy-efficient resource allocation in downlink OFDMA networks with coordinated base stations, analyzing different efficiency definitions, and optimizing user scheduling and power allocation under power constraints.

Contribution

It introduces a comprehensive framework for energy-efficient scheduling and power allocation considering multiple efficiency definitions and base station coordination.

Findings

Energy efficiency maximization aligns with spectral efficiency at low transmit powers.

Moderate data rate reductions can significantly save energy.

Coordination reduces performance gaps among strategies as interference increases.

Abstract

This paper addresses the problem of energy-efficient resource allocation in the downlink of a cellular OFDMA system. Three definitions of the energy efficiency are considered for system design, accounting for both the radiated and the circuit power. User scheduling and power allocation are optimized across a cluster of coordinated base stations with a constraint on the maximum transmit power (either per subcarrier or per base station). The asymptotic noise-limited regime is discussed as a special case. %The performance of both an isolated and a non-isolated cluster of coordinated base stations is examined in the numerical experiments. Results show that the maximization of the energy efficiency is approximately equivalent to the maximization of the spectral efficiency for small values of the maximum transmit power, while there is a wide range of values of the maximum transmit power for which a moderate reduction of the data rate provides a large saving in terms of dissipated energy. Also, the performance gap among the considered resource allocation strategies reduces as the out-of-cluster interference increases.