Fast Algorithms for Resource Allocation in Wireless Cellular Networks
IEEE/ACM Transactions on Networking, 18(3):973-984, June 2010.
We consider a scheduled orthogonal frequency division multiplexed (OFDM)
wireless cellular network where the channels from the base-station to the
mobile users undergo flat fading. Spectral resources are to be divided among
the users in order to maximize total user utility. We show that this problem
can be cast as a nonlinear convex optimization problem, and describe an
algorithm to solve it. Computational experiments show that the algorithm
typically converges in around 25 iterations, where each iteration has a cost
that is , with a modest constant.
When the algorithm starts from an initial
resource allocation that is close to optimal, convergence typically takes even
fewer iterations. Thus, the algorithm can efficiently track the optimal
resource allocation as the channel conditions change due to fading. We also
show how our techniques can be extended to solve resource allocation problems
that arise in wideband networks with frequency selective fading and when the
utility of a user is also a function of the resource allocations in the past.