Near Optimal Energy Control and Approximate Capacity of Energy Harvesting Communication · arXivDesk
1405.1156May 6, 2014To appear in JSAC Special Issue on Wireless Communications Powered by Energy Harvesting and Wireless Energy Transfer. A shorter version presented at ISIT 2014
Near Optimal Energy Control and Approximate Capacity of Energy Harvesting Communication
We consider an energy-harvesting communication system where a transmitter powered by an exogenous energy arrival process and equipped with a finite battery of size Bmax communicates over a discrete-time AWGN channel. We first concentrate on a simple Bernoulli energy arrival process where at each time step, either an energy packet of size E is harvested with probability p, or no energy is harvested at all, independent of the other time steps. We provide a near optimal energy control policy and a simple approximation to the information-theoretic capacity of this channel. Our approximations for both problems are universal in all the system parameters involved (p
Nearby in the stack
,
E
and
Bmax
), i.e. we bound the approximation gaps by a constant independent of the parameter values. Our results suggest that a battery size
Bmax≥E
is (approximately) sufficient to extract the infinite battery capacity of this channel. We then extend our results to general i.i.d. energy arrival processes. Our approximate capacity characterizations provide important insights for the optimal design of energy harvesting communication systems in the regime where both the battery size and the average energy arrival rate are large.