초록 ▼

The satellite radio communication system of this invention provides communication between one or more service centers and an ensemble of fixed and mobile user terminals. One or more earth orbiting satellites are provided with each satellite having transmitter forming a down-link channel which is slo

The satellite radio communication system of this invention provides communication between one or more service centers and an ensemble of fixed and mobile user terminals. One or more earth orbiting satellites are provided with each satellite having transmitter forming a down-link channel which is slow frequency hopped, and a multi-beam antenna system with a single channel per beam to time division multiple broadcast signals to all user terminals covered by each said beam, respectively. Each user terminal includes a transceiver for receiving a down-link channel broadcast from the one of said beams in whose path it lies, and a return link comprised of a dedicated narrow band broadcast channel with slow frequency hopping of down-link channel. There is a fixed set of frequencies through which the frequency hopping is carried out, with the plurality of fixed and mobile user terminals using the same set of frequency hopping frequencies. Mutually synchronized transmissions from each user is such that while the ensemble of users display the same set of frequency hopping frequencies, each user in said ensemble of fixed and mobile user terminals employs a unique frequency at each instant of time.

대표청구항 ▼

A reliable, power efficient and cost-effective satellite radio communication system for providing communication between one or more service centers and an ensemble of fixed and mobile user terminals, comprising, in combination: one or more earth orbiting satellites, each satellite having transmitter

A reliable, power efficient and cost-effective satellite radio communication system for providing communication between one or more service centers and an ensemble of fixed and mobile user terminals, comprising, in combination: one or more earth orbiting satellites, each satellite having transmitter means forming a down-link channel, including means to slow frequency hop said down-link channel with a set of frequency hopping frequencies, and a multibeam antenna system with a single channel per beam to time division multiple access broadcast signals to all user terminals covered by each one of said beams, respectively, each said user terminal including transceiver means for receiving one of said down-link channel broadcast from the one of said beams in whose path it lies, and a return link means comprised of a narrow band broadcast channel, means for slow frequency hopping said return-link channel, there being a fixed set of frequencies through which said slow frequency hopping is carried out, said ensemble of fixed and mobile user terminals using the same fixed set of frequency hopping frequencies, and means to mutually synchronize transmissions from each user so that while the ensemble of fixed and mobile user terminals use the same fixed set of frequency hopping frequencies, each user in said ensemble of fixed and mobile user terminals employs a unique frequency at each instant of time.