US 12,438,579 B2
Beamforming using sparse antenna arrays
Brian G. Greinke, Carlsbad, CA (US); John Bacigalupi, Carlsbad, CA (US); Craig A. Miller, Carlsbad, CA (US); and Parker A. Robinson, Ocala, FL (US)
Assigned to Viasat, Inc., Carlsbad, CA (US)
Appl. No. 18/024,719
Filed by Viasat Inc., Carlsbad, CA (US)
PCT Filed Sep. 2, 2021, PCT No. PCT/US2021/048908
§ 371(c)(1), (2) Date Mar. 3, 2023,
PCT Pub. No. WO2022/051531, PCT Pub. Date Mar. 10, 2022.
Claims priority of provisional application 63/075,017, filed on Sep. 4, 2020.
Prior Publication US 2023/0370133 A1, Nov. 16, 2023
Int. Cl. H04B 7/06 (2006.01); H04B 7/08 (2006.01); H04B 7/185 (2006.01)
CPC H04B 7/0617 (2013.01) [H04B 7/086 (2013.01); H04B 7/18513 (2013.01)] 30 Claims
OG exemplary drawing
 
1. A method for communications, comprising:
forming, by an antenna array implemented on one or more satellites, a plurality of discovery beams within a geographic area, each discovery beam of the plurality of discovery beams formed by a corresponding antenna subarray of the antenna array, wherein the antenna subarrays of the antenna array are deployed in a space orbit, wherein each antenna subarray of the antenna subarrays comprises a respective set of evenly distributed antennas, and wherein a distance between adjacent antenna subarrays of the antenna array is different across the antenna array;
detecting, using a first discovery beam of the plurality of discovery beams, a first preamble transmitted from a first terminal, wherein the first discovery beam is formed using a first antenna subarray of the antenna array and comprises a first discovery area within the geographic area;
detecting, using a second discovery beam of the plurality of discovery beams, a second preamble transmitted from a second terminal, wherein the second discovery beam is formed using a second antenna subarray of the antenna array and comprises a second discovery area within the geographic area;
determining a presence of the first terminal in the first discovery area based at least in part on detecting the first preamble and a presence of the second terminal in the second discovery area based at least in part on detecting the second preamble; and
processing, based at least in part on determining the presence of the first terminal in the first discovery area, a plurality of signals transmitted from the first terminal and detected at the first antenna subarray and the second antenna subarray according to beam coefficients to obtain a beam signal of a communication beam, the communication beam comprising a beam coverage area within the first discovery area that includes a position of the first terminal within the first discovery area, each detected signal of the plurality of signals comprising a respective component of a communication signal transmitted by the first terminal, wherein a quantity of antennas distributed across the first antenna subarray and the second antenna subarray that detect the plurality of signals is greater than a quantity of antennas at the first antenna subarray used to form the first discovery beam.