Quality of service aware antenna selection scheme for multi-hop relay networks.

Multi input multi output (MIMO) based multi-hop relay (MHR) networks has become one of the promising technologies in improving the quality of wireless links. The optimal antenna selection is one of the suitable solutions to overcome the limitations of MIMO scheme. To attain the full benefits of transmitter antenna selection schemes, perfect channel quality information (CQI) is required at the transmitter. The time varying channel and the feedback delay make CQI at the transmitter outdated and also affect the antenna selection process. In this work, we have derived the symbol error probability (SEP) of M-ary quadrature amplitude modulation (QAM) for three different antenna selection schemes by considering the effect of delayed CQI. All these derived expressions are the function of correlation between CQI at the receiver and delayed CQI at the transmitter. The simulation results show that the antenna selection gain decreases with the decrease in correlation. It is also observed that scheme 1 based antenna selection is optimal for different constellations and more suited for MHR network. [ABSTRACT FROM AUTHOR]