Green-communications-aware cross layer optimization in IDF-HARQ system under error constraints

Relaying and hybrid automatic request are promising techniques to enhance energy efficient of wireless networks. In this paper, we consider the energy per good-frame (EPGF) of the incremental decode-and-forward relay with hybrid automatic repeat-request (IDF-HARQ), along with its cross layer optimization strategy. Specially, the IDF-HARQ circuit consumption model is first provided, which includes both the dynamic circuit power consumption and the static circuit power consumption. Then, built on the state transition model of Markov chain, the total energy consumption and the outage probability performance of the IDF-HARQ are investigated. Applying these results, the closed-form expression of the EPGF is acquired. Furthermore, the EPGF of IDF-HARQ is cross layer optimized by manipulating source node power, relay power and the modulation order. Unfortunately, the proposed optimization problem may be unconvex. Therefore, we propose a nonlinear fractional programming based algorithm to solve the problem. Simulation results shed light on that the proposed cross layer optimization strategy could cut down the EPGF, and outperforms the power allocation strategy without consideration of the frame error ratio by 3.5dB, highlighting the importance of addressing good-frame ratio.