A Survey on scheduling algorithm for downlink in LTE cellular network

Abstract

Wireless internet access was introduced to the world, which led to more mobile phone subscriptions. Data services were first available in the second generation. Later after working past a lot of challenges to achieve the needs and higher performance, the Third Generation Partnership Project (3GPP) created High Speed Packet Access (HSPA). There is a lot of demand on the mobile applications, which then requires higher data rates and low latency. So the 3GPP further started working on Long Term Evolution (LTE), that improves all necessities. The introduction of Orthogonal Frequency Division Multiplexing (OFDM) further improved throughput rate but scheduling algorithm has a greater part in increasing overall performance of network. The scheduling algorithms are used to allocate time, space and resources to the users. These algorithms have also been employed in downlink (i.e. the communication from base station to the mobile) since it requires high data rates with lower packet loss compared to uplink therefore efficient algorithms are required for downlink. This paper focuses on the detailed study and comparisons of existing downlink scheduling algorithms which are namely Proportional Fair (PF), Max-Rate, Maximum Largest Weighted Delay First, Round Robin(RR), and Exponential Rule(EXP-Rule). Moreover, this paper provides some of improvements that can be done in the above mentioned algorithms.