Fast packet scheduling algorithm based on instantaneous SIR with constraint condition assuring minimum throughput in forward link

This paper proposes a new fast packet-scheduling algorithm based on instantaneous received signal-to-inference power ratio (SIR) with a constraint condition that assures a minimum throughput (minimum throughput assured instantaneous SIR (MTA-ISIR) method hereafter) and investigates its throughput performance in high-speed downlink packet access (HSDPA). In the proposed algorithm, packet transmission is assigned with priority based on the instantaneous received SIR for users with a larger average received SIR than the prescribed threshold value, and packet transmission is fairly assigned to users who have smaller average SIR than the threshold value by raising the instantaneous SIR corresponding to the threshold value. Computer simulation results elucidate that the number of high-rate users with a user throughput more than 2-Mbps employing the proposed MTA-ISIR method is increased by approximately 1.9 (1.5) times that using the proportional fairness method while maintaining a similar level of fairness for low-rate users when the threshold value is 18 dB in a 2(1)-path Rayleigh fading channel.