A REVIEW OF DIVERSITY TECHNIQUES FOR WIRELESS COMMUNIATION SYSTEMS

Wireless communication technology is now popular worldwide and has made mobile communication very attractive and in high demand. For higher data rates to meet the ever increasing demands in mobile communications, multiple-input multiple-output (MIMO) technology has been standardized as the 4G communication systems. MIMO, a wireless communication system which utilises multiple antennas at bothsides of the transmission link, has received high attention in the last few decades due to its ability to achieve high data rate transmission. Several papers have presenteddifferent techniques in the implementation of MIMO wireless systems which include diversity methods. Physical diversity is one of these methods that is well known and can be used to combat multipath fading, a common problem in wireless communications. This paper summarizes physical diversity as well as virtual diversity techniques. The paper shows that unlike the former, virtual diversity methods such asco-operative diversity and multiuser diversity are techniques that are implementable at the network or link layer of a wireless communication system.