DRX-aware transmission policy for time varying channels with delay constraint

This paper discusses the problem of minimizing the energy used to transmit packets over a memoryless channel, with a constraint on the delay suffered by packets and a constraint on peak transmitter power. The problem is studied within discontinuous reception (DRX) supported system. Specifically, we seek a DRX-compatible transmission policy that can solve the problem without the knowledge of fading distribution and packet arrival process. To achieve this goal, we formulate the problem as a variation of finite horizon classical secretary problem (CSP) with arbitrary monotonic utility. We present key structure property of optimal solution, and utilize it to obtain the optimal policy which can be described as a threshold rule. Moreover, we also propose an off-line calculation method to obtain the thresholds with low computing complexity. With the help of the thresholds, the optimal policy can make transmission decision only based on the relative rank of channel state over present time slot and the inter-packet deadlines. The performance of the optimal transmission policy is studied via simulation. The results show that the optimal transmission policy can work efficiently in DRX-supported system with low packet drop rate and high energy efficiency.