In mobile communication systems, users in good channel state were allocated excessive resources by most of scheduling algorithms when dealing with real-time traffics, while users in bad channel state got relatively few scheduling chances. In order to guarantee the delay requirements of real-time traffics and achieve fairness among different users, a packet scheduling algorithm for real-time traffics was proposed in orthogonal frequency division multiple access (OFDMA) systems. In scheduling processes, the expired data packet discarding strategy was adopted to save system resources. Users in good channel state were scheduled in larger intervals, and cumulative packets were sent in one scheduling interval using high order modulation and coding schemes (MCS). Thus users in bad channel state were given more chances to be scheduled. Simulation results showed that the proposed algorithm could meet delay requirements for real-time traffics, and had a better performance in enhancing fairness among users than modified-largest weighted delay first (M-LWDF) and proportional fair (PF) algorithms.
