Energy Efficient Resource Allocation for HARQ with Statistical CSI in Multiuser Ad Hoc Networks

We address the problem of energy efficient power and bandwidth allocation for hybrid automatic repeat request (HARQ) in multiuser ad hoc networks with statistical channel state information (CSI) and practical modulation and coding schemes (MCS) under quality of service (QoS) constraints. Using an upper-bound of the packet error rate, we propose an algorithm to maximize the sum of the energy efficiency (SEE) of the different users. We also propose two suboptimal less-complex algorithms, one based on alternating optimization and the other on a high signal-to-noise ratio (SNR) approximation. It is shown that the proposed algorithms allow a substantial gain in term of SEE compared with conventional algorithms.