Performance Evaluation of Relayed Enhanced Long Term Evolution Advanced Network Using Decode and Forward Protocol

Abstract

The increasing demand on mobile service providers to support high rate applications has prompted the development of 4G networks. To meet the rising demand, new enhanced technologies should be implemented. LTE Advanced is one of the promising technologies. It has many components to support high data rate. The aim of this project is to study the performance of LTE Advanced Network through relay deployment as a component in LTE Advanced network and mainly use decode and forward (DF) relaying protocol. The Matlab program and WINNER-II are used to introduce different channel model environments, three main simulators were designed in different propagation scenarios. The first uses decode and forward protocol (DF) to study the effect of relay cooperation and the number of relays. Two cooperative relays scenario achieved about 66% BER reduction vs. the less relay scenarios. The next simulator compares between performances of decode and forward protocol and amplify and forward (AF) protocol. For the higher SNR and the lower of BER range the more safe communication the average reduction in BER for DF over AF in typical environments was 37% and in bad environments was 21%. The last simulator studied transmission optimization by using combination of modulation levels in relay link and access link, to optimize the relation between increasing data rate at relay link and BER at UE. Using 64QAM modulation increases data rate at relay, but the BER is high and constant even with increasing of SNR. By increasing of SNR QPSK performs better than 16QAM but with less data rate at relay and the average reduction of BER of QPSK over 16QAM was 59%.