Packet Scheduling for Downlink OFDMA Wireless Systems with Heterogeneous Traffic

Abstract

In this paper, we propose a packet scheduling algorithm for downlink OFDMA wireless systems in which users have heterogeneous traffic. The proposed scheduling algorithm not only focuses on channel state and fairness but also takes the users’ queue length into consideration. With the idea of beta deadline parameter, we convert the delay bound of real-time traffic to date rate domain QoS parameter, and extend the idea for non real-time traffic with the minimum average throughput requirement. According to the subscribers’ QoS parameter, we divide the whole band into chunks with different size flexibly. Chunks are allocated to users in accordance with the scheduling rule. Simulation results demonstrate that the proposed scheduling algorithm can acclimatize itself to active user number in the system and the users’ requirements for radio resource. Its performance in terms of spectral efficiency, packet loss ratio, and the real-time traffic packets’ delay, is better than algorithms with fixed chunk size dividing.