Throughput-Optimal Scheduling in Multichannel Access Point Networks Under Infrequent Channel Measurements

We consider the problem of uplink/downlink scheduling in a multichannel wireless access point network where channel states differ across channels as well as users, vary with time, and can be measured only infrequently. We demonstrate that, unlike the infrequent measurement of queue lengths, infrequent measurement of channel states reduce the maximum attainable throughput. We then prove in frequency division multiplexing systems, a dynamic scheduling policy that depends on both the channel rates (averaged over the measurement interval) and the queue lengths, attains the maximum possible throughput. We also generalize the scheduling policy to solve the joint power allocation and scheduling problem in orthogonal frequency division multiplexing systems. In addition, we provide simulation studies that demonstrate the impact of the frequency of channel and queue state measurements on the average delay and attained throughput.