  This paper treats power-aware throughput maxi-mization in a multi-user file
downloading system. Each user can receive a new file only after its previous
file is finished. The file state processes for each user act as coupled Markov
chains that form a generalized restless bandit system. First, an optimal
algorithm is derived for the case of one user. The algorithm maximizes
throughput subject to an average power constraint. Next, the one-user algorithm
is extended to a low complexity heuristic for the multi-user problem. The
heuristic uses a simple online index policy. In a special case with no
power-constraint, the multi-user heuristic is shown to be throughput optimal.
Simulations are used to demonstrate effectiveness of the heuristic in the
general case. For simple cases where the optimal solution can be computed
offline, the heuristic is shown to be near-optimal for a wide range of
parameters.
