Queueing analysis for the OFDMA downlink: Throughput regions, delay and exponential backlog bounds

Abstract

While multiuser scheduling strategies have been intensively studied in the context of OFDMA downlink recently, the resulting throughput and delay performance affecting strongly end-to-end performance of wireless communication systems can still be evaluated by simulations only. In this paper we approach this problem and consider bounds for delay and queue backlog for a large class of scheduling policies. Adopting a general state space Markov chain model the concept of policy-specific throughput regions is introduced. Then, under the regime of the policy, a recursive formula for calculating all polynomial moments of the queue backlog is derived. Moreover, it is shown that even exponential decay of the tail distribution can be obtained under proper circumstances. Based on these results, upper bounds on the buffer overflow probability are derived giving insights for practical buffer dimensioning problems in UMTS LTE systems.