The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 2000
Filed:
Dec. 08, 1997
Edward Jay Kent, Cherry Hill, NJ (US);
Charles Edward Profera, Jr, Blackwood, NJ (US);
Thaddeus Arthur Hawkes, Haddonfield, NJ (US);
Lockheed Martin Corp., Sunnyvale, CA (US);
Abstract
A spacecraft-based cellular communications system includes a spacecraft with transmit and receive antennas, each of which produces a plurality of spot beams which, together, provide coverage of the region served. In order to control the pointing of the spacecraft antennas, four mutually adjacent spot beams are centered over a particular 'beacon' location, so that the beacon location lies between a pair of North and South spot beams, and between a pair of East and West spot beams. The transmit antenna is controlled by transmitting a beacon signal in time sequence over each of the four spot beams surrounding the beacon location, and decoding or desequencing the time-sequential signal received at the beacon location. The decoded signal is processed to provide a signal indicating the pointing error of the transmit antenna, and the error signal is used to control a gimbal which controls the pointing of the transmit antenna. The receive antenna is independently controlled by a generally similar system, in which the beacon signal is transmitted from the beacon location to the receive antenna, and the beacon signal is selectively received from the four spot beams in a time-sequential manner. The received beacon signal is processed in much the same manner as in the transmit antenna controller, and controls a gimbal associated with the receive antenna, to cause the receive antenna to point at the beacon location. Since both transmit and receive antennas point at the beacon location, their beams can be congruent.