A CSMA/CA-based medium access scheme for array antenna-enhanced wireless ad hoc networks

We devise an incorporated medium access and beamforming scheme for packet-oriented, array antenna-enhanced ad hoc networks with time-division duplexing. The RTS-CTS-data-ACK type of channel access scheme adheres to a CSMA/CA (carrier sense multiple access / collision avoidance) policy. The beamforming is performed at both the packet sender and receiver at the beginning of a packet transmission, exploiting reciprocity of the MIMO (multiple-input/multiple-output) channels, thereby evading the complexity of instantaneous adaptive beamforming. In simulations we find that with the proposed technique the density of the concurrent single-hop packet transmissions in multi-path fading environments increases roughly linearly with the number of antennas per transceiver.