Abstract: A broadcast receiving system for use with an FM radio transmitter in a vehicle includes an adapter unit and an antenna unit. The adapter unit includes a connector to a vehicle's existing power system, e.g., cigarette lighter receptacle. The adapter unit receives audio program signals from the antenna unit, and retransmits them to a vacant FM channel or to an intermediate frequency channel of the vehicle's FM radio receiver. The antenna unit receives radio broadcast signals having frequencies in the range of about 300 MHZ to about 4000 MHz from satellites and terrestrial repeaters.
Abstract: A digital radio broadcasting system using spread spectrum modulation transmitted from both geosynchronous satellites and terrestrial repeater stations provides multi-program audio services to mobile and fixed user receivers over a large geographical area in an ubiquitous manner.
Abstract: A radio receiver augmentation system for insertion in a cassette player or compact disc player includes a receiver unit and an antenna unit. The receiver unit includes an insertable element having a size and shape suitable for insertion in a tape cassette receiving slot of a cassette player/radio combination or in a compact disc receiving slot of a compact disc player/radio combination and delivers audio program signals to the magnetic head of the tape cassette player or the optical coupler of the compact disc player. The audio program signals come by retransmission from an antenna unit that receives radio broadcast signals from satellites and their terrestrial repeaters having frequencies in the range of about 300 MHZ to about 4000 MHZ. The system's circuitry conditions the signal for aural presentation through the tape cassette player/radio combination or compact disc player/radio combination.
Abstract: A multicarrier satellite communications system includes one or more satellites and one or more transmitters at generally terrestrial locations that transmit a plurality of signal carriers to the satellites which contain non-linear signal repeaters that produce inter-modulation noise or signal compression in the signal carriers. The noise is minimized/cancelled by adding to the signal carriers, at the generally terrestrial locations where the transmitters are located, noise-cancelling or signal compression-correcting signals.
Abstract: Mobile radio receivers in a broadcasting system having more than one transmission channel sending the same programs use time diversity to prevent service outages during periods when none of the channels can be received.
Abstract: The methods and systems for reducing multipath fading and outage from blockage in a radio broadcasting system that is adapted to simultaneously broadcast signals having frequencies in the range of about 300 MHz to about 3,000 MHz from two or more satellite sources traveling on a substantially geosynchronous orbit with the satellite sources separated from one another by a sufficient distance to minimize outage from physical blockages and multipath fading of signals from these satellites and received by a plurality of fixed and mobile platforms using substantially flat, hemispherical coverage antennas, each antenna having an outer diameter no greater than about 10 inches and each adapted to receive frequencies in the range of about 300 MHz to about 3,000 MHz.
April 13, 1994
Date of Patent:
January 16, 1996
CD Radio Inc.
Robert D. Briskman, John M. Seavey, Paul Medeiros
Abstract: High quality audio broadcasts at radio frequencies to mobile receivers at or near the earth's surface are provided by substantially simultaneous transmission of the same signal from two geosynchronous, spatially-separated satellites on the geosynchronous orbit which virtually eliminates multipath fading and foliage attenuation and thereby permits the use of a low-cost space segment.