초록 ▼

An existing TDRSS satellite communication system is incorporated, together with low-power ground-based remote transceivers of special design, and additional beamforming and steering elements at the ground terminals, to make possible digital communication between low power field transceivers and sate

An existing TDRSS satellite communication system is incorporated, together with low-power ground-based remote transceivers of special design, and additional beamforming and steering elements at the ground terminals, to make possible digital communication between low power field transceivers and satellite ground terminals. The satellite communication system transmits to its ground terminals a composite signal, comprising amplified, phase-coherent signals received by an array of broad-coverage antennas on the satellite. The field transceiver transmits a pseudonoise coded signal spread across all or a portion of the satellite's receive bandwidth. At the ground terminals, the downlinked composite signal is processed by a beamformer to define a narrow, high-gain beam between the satellite and low-power transceiver. Signal processing gain and beamformer gain in combination serve to elevate the received, demodulated signals well above the noise level at the receiver. Through this invention, a large multiplicity of non-interfering reverse-link (remote-to-central) communication channels may be supported by a host satellite communication system of the nature described. By the introduction of forward link signal channels into the satellite ground terminal, and scheduling of forward link transmissions to the set of low-power remote transceivers along with normal transmit activities, highly useful two-way communication can be extended to a class of users not initially served by the satellite communication system.

대표청구항 ▼

[ What is claimed is:] [1.] In a tracking and data relay satellite system having a satellite communication system that derives satellite antenna pointing/nulling through a linear, weighted combination of multiple signals at a ground terminal, and wherein the signals are derived from an array of broa

[ What is claimed is:] [1.] In a tracking and data relay satellite system having a satellite communication system that derives satellite antenna pointing/nulling through a linear, weighted combination of multiple signals at a ground terminal, and wherein the signals are derived from an array of broad-coverage antenna elements on one or more earth orbiting satellites having a space-to-ground link with a composite downlink signal composed of the signals from the elements, the improvement wherein the beams formed on the ground for the return link and on the satellite for the forward link are structured so as to null one or more regions within their field of view.