Performance Analysis of Scheduling Algorithms in OFDM Systems

Abstract

A smart phone without Internet is obsolete in today’s world. With multitude of applications hosted in the personal handheld devices, the need of high-speed Internet access has increased manifold. On one hand, in order to meet these demands, LTE-A (a.k.a. 4G) started a new era of improved network capacity as well as higher bandwidth availability to each user, while on the other hand the resource allocation for users has emerged as an active research area. Parameters such as number of users, channel conditions, type of traffic class and so on play an important role while designing a scheduling algorithm. In order to create a network which can sustain itself (self-controlled), deployments of schemes and methods are required everywhere. One such scenario which is prevalent in LTE is CQI reporting on which complete packet scheduling is directly dependent. While CQI does change the way the network is ordered, an imperfect or lost CQI value makes the packet scheduling difficult and unimaginable. Advanced wireless networks such as 4G LTE have effective ways of reporting channel quality through CQI values of the time and frequency varying channel whether it is fast fading or slow fading. The main objective of using CQI values is to schedule the resource blocks and maintain proper SNR by adjusting signal power or modulation. In doing so, one must precisely be able to map CQI values to SNR values so that the objectives can be fulfilled properly where an imperfect mapping can hamper the performance of wireless system as packet scheduling can become difficult and unmanageable