Scheduling for multi-channel wireless networks: Small delay with polynomial complexity

Scheduling for multi-channel (e.g., OFDM-based) wireless downlink systems is considered with the objective of providing low delay performance to users with real-time and stochastic traffic. The main contribution is the design of a low-complexity scheduling algorithm for the system with desired performance (in a large deviations sense). In particular, as the number of users and channels grows, the algorithm ensures an exponential decay of the probability of encountering significant delay at a near optimal decay rate when the arrivals are symmetric and the channel follows an ON-OFF model with multi-packet reception. The algorithm also provides consistently good performance in the larger set up by guaranteeing throughput optimality, and a non-zero decay rate if it is possible under any other algorithm.