Wireless networks with energy harvesting battery powered nodes are quicklyemerging as a viable option for future wireless networks with extendedlifetime. Equally important to their counterpart in the design of energyharvesting radios are the design principles that this new networking paradigmcalls for. In particular, unlike wireless networks considered up to date, theenergy replenishment process and the storage constraints of the rechargeablebatteries need to be taken into account in designing efficient transmissionstrategies. In this work, we consider such transmission policies forrechargeable nodes, and identify the optimum solution for two related problems.Specifically, the transmission policy that maximizes the short term throughput,i.e., the amount of data transmitted in a finite time horizon is found. Inaddition, we show the relation of this optimization problem to another, namely,the minimization of the transmission completion time for a given amount ofdata, and solve that as well. The transmission policies are identified underthe constraints on energy causality, i.e., energy replenishment process, aswell as the energy storage, i.e., battery capacity. The power-rate relationshipfor this problem is assumed to be an increasing concave function, as dictatedby information theory. For battery replenishment, a model with discrete packetsof energy arrivals is considered. We derive the necessary conditions that thethroughput-optimal allocation satisfies, and then provide the algorithm thatfinds the optimal transmission policy with respect to the short-term throughputand the minimum transmission completion time. Numerical results are presentedto confirm the analytical findings.
展开▼
