Diversity in 4G

Abstract

The main subject of this project is to deeply study the diversity characteristics of the MIMO antennas, which will be adopted in 4G systems. The project discusses the performance of Diversity in MIMO, and then it explains how diversity reception and transmission technique is used to mitigate the effects of fading over communication link. The project handles Space-Time Block Coding (STBC) transmit diversity combined with receive diversity scheme when the Channel is perfectly known to the receiver unknown to the transmitter in order to achieve diversity in MIMO. The results of the simulation show that the Diversity performance of N M system using STBC improves when N or M or both increase. Orthogonality shows a great effect on the system performance, increasing orthogonality reduced BER. Moreover reducing the code rate has a bad impact on the system performance. Anew Quasi-OSTBC for 16 M was introduced in this project benefitting from known orthogonal design for STBC matrices. Channel estimator is used to estimate channel information when the channel is unknown to the receiver using pilot signals.