Improving throughput and fairness for MIMO ad hoc networks using antenna selection diversity

This paper presents a new MAC protocol, mitigating interference using multiple antennas with antenna selection (MIMA/AS-MAC), which uses multiple antennas to mitigate both interference from neighboring transmitters and fading. The proposed MIMA/AS-MAC protocol employs spatial multiplexing with antenna subset selection for data packet transmission, while using the Alamouti space-time code for control of packet transmission. To study its performance, the MIMA/AS-MAC was implemented in the ns-2 network simulator for a system with two antennas. The total network throughput and fairness between two traffic flows was measured. The results show that the MIMA/AS-MAC system outperforms the previously proposed MIMA-MAC scheme, which does not use an antenna selection scheme, as well as a hybrid of the IEEE 802.11 MAC protocol with Alamouti encoding.