On Optimizing Power Allocation For Reliable Communication over Fading Channels with Uninformed Transmitter

TL;DR

This paper proposes an energy-efficient power allocation strategy for reliable communication over slow-fading channels without channel state information at the transmitter, using stochastic optimization to minimize power consumption.

Contribution

It introduces a novel optimization framework linking power, reliability, and data transfer constraints, employing simulated annealing to solve non-convex problems in fading channels.

Findings

Significant energy savings achieved with less stringent reliability requirements.

The optimization framework effectively balances power and reliability in fading channels.

Use of stochastic optimization improves solution quality for non-convex problems.

Abstract

We investigate energy efficient packet scheduling and power allocation problem for the services which require reliable communication to guarantee a certain quality of experience (QoE). We establish links between average transmit power and reliability of data transfer, which depends on both average amount of data transfer and short term rate guarantees. We consider a slow-fading point-to-point channel without channel state information at the transmitter side (CSIT). In the absence of CSIT, the slow fading channel has an outage probability associated with every transmit power. As a function of data loss tolerance parameters, and minimum rate and peak power constraints, we formulate an optimization problem that adapts rate and power to minimize the average transmit power for the user equipment (UE). Then, a relaxed optimization problem is formulated where transmission rate is assumed to be fixed for each packet transmission. We use Markov chain to model constraints of the optimization problem. The corresponding problem is not convex for both of the formulated problems, therefore a stochastic optimization technique, namely the simulated annealing algorithm, is used to solve them. The numerical results quantify the effect of various system parameters on average transmit power and show significant energy savings when the service has less stringent requirements on timely and reliable communication.