  In this paper, we study power management (PM) policies for an Energy
Harvesting Additive White Gaussian Noise (EH-AWGN) channel. The arrival rate of
the harvested energy is assumed to remain unchanged during each data frame
(block code) and to change independently across block codes. The harvested
energy sequence is known causally (online) at the transmitter. The transmitter
is equipped with a rechargeable battery with infinite energy storage capacity.
The transmitter is able to adapt the allocated energy and the corresponding
transmission rate of each block according to a PM policy. Three novel online PM
policies are established. The policies are universal, in the sense of the
distribution of the harvested energy, and simple, in the sense of complexity,
and asymptotically optimal, in the sense of maximum achievable average rates
(throughput) taken over a long-term horizon of blocks.
