Emerging adaptive antenna techniques for wireless ad-hoc networks

The effects of adaptive antennas on the performance of wireless ad-hoc networks are theoretically clarified. Their beam- and null-steering functionality saves transmission energy, suppresses co-channel interference, and increases the throughput of the network. An analog-based beamforming architecture is introduced as an adaptive antenna suitable for battery-operated terminal devices. In spite of its simple configuration, adaptive beamforming is successfully achieved by using an iterative perturb-gradient-update training procedure.