Energy Efficient Resource Allocation in SC-FDMA Uplink with Synchronous HARQ Constraints

In this paper we propose framework for energy efficient (margin adaptive, MA) resource allocation in multiuser SC-FDMA under synchronous HARQ constraints. Resource allocation is formulated as a two-stage problem where resources are allocated in both time and frequency. To limit the impact of retransmissions on the time-frequency problem segmentation, we propose use of a block scheduling interval that ensures uplink users do not experience ARQ blocking. We formulate the optimal MA resource allocation problem under this framework and based on its structure, we propose a variable complexity sub-optimal approach to solving the resource allocation problem. The proposed method´s performance is shown to minimize transmission energy for low complexity implementation.