Design and development of scheduling algorithms for downlink transmission system of Long Term Evolution (LTE) network

Abstract

In today‟s technology development, people need internet access wherever they are, mobile broadband will grow up actively. Therefore, service providers gradually compete to produce the maximum internet speed for public uses. To enable high-speed data services to mobile users, scheduling technique gained significant attention in wireless access networks. A feature of the wireless environment is that the quality of the different channels of the user population due to a conflict path loss and effect of the attenuation. The best scheduler should provide high throughput, low latency system and the best coverage gains. In order to develop the best scheduling, the scheduler must be aware of the channel quality and scheduler should have associate of the channel quality for each sub carrier and each user. In order to exploit the diversity of multiuser in addition to deliver further compliance in resource allocation, an algorithm is proposed in this work where system latency is considered as the first priority in scheduling steps and followed by arrangement of user equipments (UEs) according to the Channel Quality Indicator (CQI) scheduler for Long Term Evolution (LTE) structure. The analysis and the comparison of these scheduling algorithms were prepared over simulations done by a MATLAB-based downlink system level simulator from the Vienna University. The main target in this thesis is to propose a new scheduling for resources allocation that may be compromise between throughput and fairness to avoid useless space in a scheduler. Useless space may cause the latency that may cause of delay in transmission. The Round Robin (RR) scheduler and best CQI scheduler are considered in this research work. There are two (2) enhanced scheduling algorithms proposed in this research work which are Resource Fairness (RF) and Maximum Throughput (Max TP) scheduling algorithm. The enhanced scheduling algorithms have been proposed based on Proportional Fair (PF) scheduling algorithm. PF is one‟s of scheduling algorithm that have compromise between throughput and fairness. From the observation, it shows that RF scheduling algorithm has been achieved about 19% of improvement in term of fairness index compared to other scheduling algorithm for all type of network scenarios. While Max TP scheduling algorithm has provide about 25% of improvement in term of throughput for all network scenario. Since RF scheduling algorithm provide second highest throughput value which having about 11% of improvement compared to other scheduling algorithm, it may be considered that RF scheduling algorithm has achieved high compromise between fairness and throughput compared to PF scheduling algorithm.