US 12438579 B2 / Oct 7, 2025

Beamforming using sparse antenna arrays

An antenna array may be associated with forming discovery beams within a geographic area, where each discovery beam may be formed by a corresponding set of antennas of the antenna array and cover a discovery area within the geographic area. Preambles transmitted from terminals within a discovery area of a discovery beam may be detected using the antenna array. Based on detecting a preamble using a discovery beam, a presence of a terminal in a corresponding discovery area may be determined. Based on determining the presence of the terminal, signals detected at a second set of antennas of the antenna array may be processed according to beam coefficients to obtain a beam signal of a communication beam that includes a beam coverage area encompassing a position of the terminal. Each detected signal may comprise a respective component of a signal transmitted by the terminal.