Energy-Aware Resource Allocation Strategies for LTE Uplink with Synchronous HARQ Constraints

In this paper, we propose a framework for energy efficient resource allocation in multiuser localized SC-FDMA with synchronous HARQ constraints. Resource allocation is formulated as a two-stage problem where resources are allocated in both time and frequency. The impact of retransmissions on the time-frequency problem segmentation is handled through the use of a novel block scheduling interval specifically designed for synchronous HARQ to ensure uplink users do not experience ARQ blocking. Using this framework, we formulate the optimal margin adaptive allocation problem, and based on its structure, we propose two suboptimal approaches to minimize average power allocation required for resource allocation while attempting to reduce complexity. Results are presented for computational complexity and average power allocation relative to system complexity and data rate, and comparisons are made between the proposed optimal and suboptimal approaches.

1 Introduction

Energy efficient communication is a long-standing issue in modern wireless communication systems. The mobile device radio accounts for a large portion of a mobile device's battery life, and as such, efficient use of radio resources can dramatically improve mobile device energy consumption. With the increased proliferation of smaller and faster devices, it has become essential to efficiently utilize mobile battery resources.