Universally Near Optimal Online Power Control for Energy Harvesting Nodes

We consider online power control for an energy harvesting system with random i.i.d. energy arrivals and a finite size battery. We propose a simple online power control policy for this channel that requires minimal information regarding the distribution of the energy arrivals and prove that it is universally near-optimal for all parameter values. In particular, the policy depends on the distribution of the energy arrival process only through its mean and it achieves the optimal long-term average throughput of the channel within both constant additive and multiplicative gaps. Existing heuristics for online power control fail to achieve such universal performance. This result also allows us to approximate the long-term average throughput of the system with a simple formula, which sheds some light on the qualitative behavior of the throughput, namely how it depends on the distribution of the energy arrivals and the size of the battery.Comment: the proposed scheme is shown to be optimal both within constant additive and multiplicative gaps; submitted to Journal on Selected Areas in Communications - Series on Green Communications and Networking (Issue 3); revised following reviewers' comment

Stock Prices, Exchange Rates and Monetary Policy

This paper attempts to model the relationship between monetary policy and financial asset prices. We develop an aggregative model under forward-looking rational expectations to analyse the optimal monetary policy response to stock prices and exchange rates shocks. We first demonstrate that a model ignoring the impact of equity prices and exchange rates on aggregate demand leads to an overestimation of the optimal policy response to standard shocks. Second, we clearly point out that a correct assessment of the relation between optimal monetary policy and either equity prices or exchange rates necessitates a model including both kinds of financial prices simultaneously. Third, we show how these interactions between financial asset prices and monetary policy are affected by a particular form of coordination between monetary policy and fiscal policy, arising from a public debt solvency constraint.Monetary policy; financial asset prices; monetary conditions indicator