QoS Oriented Time and Frequency Domain Packet Schedulers for The UTRAN Long Term Evolution

In this paper we introduce orthogonal frequency division multiple access (OFDMA) downlink general packet scheduling methods for throughput fairness control among users. The investigation is based on the 3GPP UTRAN long term evolution (LTE) and a decoupled time/frequency domain packet scheduler approach is used. It is shown that fairness can be effectively controlled with frequency domain metric weighting or time domain priority set scheduling (TD-PSS) depending on the number of users in the cell. Furthermore we introduce a principle of metric decoupling between time and frequency domain schedulers that is fundamental for maximizing throughput control. The algorithms are simulated in best effort (BE) and constant bit rate (CBR) users conditions. They are shown to provide coverage gains of up to 60% for a cell throughput loss of 5 % over the well known time-frequency domain proportional fair scheduler.