Terahertz Transmit Beamforming with 1-Bit DACs and ADCs

This paper tackles the problem of transmit beamforming with 1-bit digital-to-analog and analog-to-digital converters. While, at frequencies above 100 GHz, such 1-bit converters are instrumental to restrain the power consumption and enable transmissions spanning many giga-hertz of bandwidth, they fundamentally alter the nature of the communication problem. Transmit beamforming, a key task when communicating at these high frequencies, then amounts to identifying the quartet of channel-dependent transmit vectors that maximizes the mutual information. This problem, which becomes unwieldy for even modest numbers of antennas, is herein tackled by means of an unsupervised learning approach that proves effective for very large arrays.