Performance Analysis of Scheduling Algorithms in OFDM Systems

Abstract

A smart phone without Internet is obsolete in today s world. With newlinemultitude of applications hosted in the personal handheld devices, the need of newlinehigh-speed Internet access has increased manifold. On one hand, in order to meet newlinethese demands, LTE-A (a.k.a. 4G) started a new era of improved network newlinecapacity as well as higher bandwidth availability to each user, while on the other newlinehand the resource allocation for users has emerged as an active research area. newlineParameters such as number of users, channel conditions, type of traffic class and newlineso on play an important role while designing a scheduling algorithm. In order to newlinecreate a network which can sustain itself (self-controlled), deployments of newlineschemes and methods are required everywhere. One such scenario which is newlineprevalent in LTE is CQI reporting on which complete packet scheduling is newlinedirectly dependent. While CQI does change the way the network is ordered, an newlineimperfect or lost CQI value makes the packet scheduling difficult and newlineunimaginable. Advanced wireless networks such as 4G LTE have effective ways newlineof reporting channel quality through CQI values of the time and frequency newlinevarying channel whether it is fast fading or slow fading. The main objective of newlineusing CQI values is to schedule the resource blocks and maintain proper SNR by newlineadjusting signal power or modulation. In doing so, one must precisely be able to newlinemap CQI values to SNR values so that the objectives can be fulfilled properly newlinewhere an imperfect mapping can hamper the performance of wireless system as newlinepacket scheduling can become difficult and unmanageable. newlineNext generation networks are envisioned to have ubiquitous availability newlineand seamless access as main goals. In general, coexistence of multiple access newlinetechnologies is one of the most promising way to achieve these goals, particularly newlineusing WiFi and LTE simultaneously which are two major players in future newlinevii newlineInternet. LTE is primarily used in a licensed spectrum but an unlicensed version newlineis also in use by research communities. newlineFi