Mobile radio receivers using time diversity to avoid service outages in multichannel broadcast transmission systems
First Claim
Patent Images
1. A method for substantially eliminating service outages from various causes, including physical blockage, multipath fading and electronic interference, by the transmission of at least two radio broadcast signals having frequencies in the range of about 300 MHZ to about 3,000 MHZ, and having substantially the same content to a plurality of mobile receivers for said signals comprising:
- broadcasting a first radio broadcast signal to said plurality of mobile receivers;
after a time delay of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 seconds, following the broadcast of said first radio broadcast signal, broadcasting a second radio broadcast signal containing substantially the same program content as said first radio broadcast signal to said plurality of mobile receivers;
storing, in each of said mobile receivers, said first radio broadcast signal for a time period substantially the same as the time of said time delay; and
outputting from each of said plurality of mobile receivers, the program contents of said first and said second radio broadcast signals by combining said first and said second radio broadcast signals for output or by selecting for output, in correct time-ordered progression, portions of said first radio broadcast signal and portions of said second radio broadcast signal.
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Accused Products
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.
330 Citations
44 Claims
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1. A method for substantially eliminating service outages from various causes, including physical blockage, multipath fading and electronic interference, by the transmission of at least two radio broadcast signals having frequencies in the range of about 300 MHZ to about 3,000 MHZ, and having substantially the same content to a plurality of mobile receivers for said signals comprising:
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broadcasting a first radio broadcast signal to said plurality of mobile receivers; after a time delay of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 seconds, following the broadcast of said first radio broadcast signal, broadcasting a second radio broadcast signal containing substantially the same program content as said first radio broadcast signal to said plurality of mobile receivers; storing, in each of said mobile receivers, said first radio broadcast signal for a time period substantially the same as the time of said time delay; and outputting from each of said plurality of mobile receivers, the program contents of said first and said second radio broadcast signals by combining said first and said second radio broadcast signals for output or by selecting for output, in correct time-ordered progression, portions of said first radio broadcast signal and portions of said second radio broadcast signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 39, 40, 41)
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- 13. A mobile receiver for outputting a substantially continuous, time-ordered radio broadcast signal derived from at least two radio broadcast signals having frequencies in the range of about 300 MHZ to about 3,000 MHZ, and having substantially the same program content received by said mobile receiver at two different times and stored in said mobile receiver, comprising, in said mobile receiver, a system for storing at least one of the two said radio broadcast signals, said storage system including means for delaying output of the earlier received of the two broadcast signals for a time equal to the time differential between the same program element of the first and second signal in said receiver, said delay being at least about 0.5 seconds in length, and a system for converting said signals for output as a sound, visual or data signal, whereby service outages from various causes, including physical blockage, multipath fading and electronic interference in the transmission of said at least two radio broadcast signals, are substantially eliminated.
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19. A radio broadcast method for broadcasting signals having frequencies in the range of about 300 MHZ to about 3,000 MHZ comprising:
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broadcasting a first radio broadcast signal using spread spectrum modulation from a first satellite source traveling on a geosynchronous orbit; after a time delay of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 seconds, following the broadcast of said first radio broadcast signal, broadcasting a second radio broadcast signal using spread spectrum modulation, said second radio broadcast signal having substantially the same content and frequency as said first radio broadcast signal from a second satellite source on said geosynchronous orbit, said second satellite source being spaced from said first satellite source a predetermined number of degrees to reduce further multipath fading and to reduce further signal attenuation from physical objects in the paths of said first radio broadcast signal and said second radio broadcast signal and producing an output signal from said first radio broadcast signal and said second radio broadcast signal at a plurality of mobile receivers located at or near the surface of the earth. - View Dependent Claims (20, 21, 22, 43)
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23. A method for reducing satellite-based transmitter power in a radio broadcasting system adapted to broadcast radio broadcast signals having frequencies in the range of about 300 MHZ to about 3,000 MHZ comprising:
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broadcasting on a first path a first radio broadcast signal that includes audio program information from a first satellite source traveling on a substantially geosynchronous orbit; after a delay time of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 second, following the broadcast of said first radio broadcast signal, broadcasting on a second path a second radio broadcast signal having substantially the same content and frequency as said first radio broadcast signal from a second satellite source on said substantially geosynchronous orbit, said second satellite source and said second path being spaced from said first satellite source and said first path a predetermined number of degrees to reduce further the power needed to transmit said first and said second radio broadcast signals to a receiver at or near the earth'"'"'s surface; and assembling and producing said broadcast signal as an output signal from said first radio broadcast signal and said second radio broadcast signal at a plurality of mobile receivers having at least one channel to receive said first radio broadcast signal and at least one channel to receive said second broadcast signal located at or near the earth'"'"'s surface. - View Dependent Claims (34, 35, 36, 37, 38)
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24. A method for reducing satellite-based transmitter power in a radio broadcasting system adapted to broadcast radio broadcast signals having frequencies in the range of about 300 MHZ to about 3,000 MHZ comprising:
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broadcasting on a first path a first radio broadcast signal that includes audio program information from a first satellite source traveling on a substantially geosynchronous orbit; after a time delay of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 seconds, following the broadcast of said first radio broadcast signal, broadcasting on a second path a second radio broadcast signal with substantially identical content from a second satellite source on said substantially geosynchronous orbit, said second satellite source and said second path being spaced from said first satellite source and said first path a predetermined number of degrees to reduce further the power needed to transmit said first and said second radio broadcast signals to the earth'"'"'s surface, said second radio broadcast signal having a frequency different from the frequency of said first radio broadcast signal; and assembling and producing said radio broadcast signal as an output signal from said first and said second radio broadcast signals at a plurality of mobile receivers having at least one channel to receive said first radio broadcast signal and at least one channel to receive said second radio broadcast signal located at or near the surface of the earth.
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25. A method for improving signal reception in a radio broadcast system comprising:
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broadcasting on a first path a first radio broadcast signal that includes audio program information having a frequency in the range of about 300 MHZ to about 3,000 MHZ from a first satellite source traveling on a substantially geosynchronous orbit; after a time delay of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 seconds, following the broadcast of said first radio broadcast signal, broadcasting on a second path a second radio broadcast signal with identical content having substantially the same frequency as said first radio broadcast signal or having a frequency different from the frequency of said first radio broadcast signal from a second satellite source on said substantially geosynchronous orbit, said second satellite source and said second path being spaced from said first satellite source and said first path a predetermined number of degrees to improve further the reception of said first and said second radio broadcast signals at a plurality of mobile receivers located at or near the earth'"'"'s surface; and assembling and producing said radio broadcast signal as an output signal from said first radio broadcast signal and said second radio broadcast signal at said plurality of mobile receivers having at least one channel to receive said first radio broadcast signal and at least one channel to receive said second radio broadcast signal.
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26. A method for reducing foliage attenuation and signal outage from radio path blockage in a radio broadcasting system adapted to broadcast signals having frequencies in the range of about 300 MHZ to about 3,000 MHZ comprising:
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broadcasting on a first path a first radio broadcast signal that includes audio program information having a frequency in said range from a first satellite source traveling on a substantially geosynchronous orbit; after a time delay of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 seconds, following the broadcast of said first radio broadcast signal, broadcasting on a second path a second radio broadcast signal with identical content having substantially the same frequency as said first radio broadcast signal or having a frequency different from the frequency of said first radio broadcast signal from a second satellite source on said geosynchronous orbit, said second satellite source and said second path being spaced from said first satellite source and said first path a predetermined number of degrees to minimize further foliage attenuation or radio path blockage; and assembling and producing said radio broadcast signal as an output signal from said first radio broadcast signal and said second radio broadcast signal at a plurality of mobile receivers having at least one channel to receive said first radio broadcast signal and at least one channel to receive said second radio broadcast signal located at or near the surface of the earth.
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27. A UHF radio system adapted to broadcast signals having frequencies in a range of about 300 MHZ to about 3,000 MHZ comprising:
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a broadcasting source for broadcasting on a first path a first radio broadcast signal that includes audio program information on a first satellite source traveling in a substantially geosynchronous orbit; a broadcasting source for broadcasting, on a second path, after a time delay of sufficient length to substantially eliminate said service outages, said delay being at least about 0.5 seconds, following the broadcast of said first radio broadcast signal, a second radio broadcast signal from a second satellite source traveling in said substantially geosynchronous orbit, said second satellite source and said second path being spaced from said first satellite source and said first path a predetermined number of degrees to minimize further outage and fading of said first and said second radio broadcast signals; and a plurality of mobile receivers for receiving said first and said second radio broadcast signals, each of said mobile receivers being located at or near the surface of the earth, each of said receivers being adapted to produce said radio broadcast signal as an output signal from said first and said second radio broadcast signals, each of said receivers including at least one channel to receive said first radio broadcast signal and at least one channel to receive said second radio broadcast signal, each of said receivers including means for storing said first and said second radio broadcast signals, and means for outputting said audio program with minimal interruption using portions of said first stored signal, portions of said second stored signal, or both. - View Dependent Claims (28, 29, 30, 31, 32, 33, 44)
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Specification