Control of mobile communications with time-varying channels in heavy traffic

Consider the forward link of a system with K remote units and a single base transmitter with time varying connecting channels. Data to be transmitted to the remote units arrives according to some random process, and is queued according to its destination. Power is to be allocated to the K channels in a queue and channel state depend on way to minimize some cost criterion. The channel fading rate is fast and the bandwidth and data arrival rates are high. Owing to the high speed of the fading, arrival, and service rates, an asymptotic or averaging of the heavy traffic type method is promising. By heavy traffic, we mean that on the average there is little server idle time and spare power over the "average" requirements. Heavy traffic analysis eliminates inessential details and focuses on the fundamental issues of scaling and parametric dependencies. To illustrate the scope of the method, several models are considered, and more complicated systems are also treated.