Diversity-oriented channel allocation in a mobile communications system
First Claim
1. A method of communications with a plurality of ground terminals using a plurality of satellites transmitting time-division multiplexed signals, comprising the steps of:
- transmitting from a first satellite to a first group of ground terminals using a first number of timeslots in a TDM frame period;
transmitting from said first satellite and a second satellite in alternate TDM frames to a second group of ground terminals using a second number of timeslots in said TDM frame period; and
transmitting from said second satellite to a third group of ground terminals using a third number of timeslots in said TDM frame period.
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0 Petitions
Accused Products
Abstract
A method and apparatus for communicating with a plurality of ground terminals using a plurality of satellites transmitting time-division multiplexed signals are disclosed. First, a first satellite transmits to a first group of ground terminals using a first number of timeslots in a TDM frame period. In addition, the first satellite and a second satellite transmit in alternate TDM frames to a second group of ground terminals using a second number of timeslots in said TDM frame period. Finally, the second satellite transmit to a third group of ground terminals using a third number of timeslots in the TDM frame period.
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Citations
27 Claims
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1. A method of communications with a plurality of ground terminals using a plurality of satellites transmitting time-division multiplexed signals, comprising the steps of:
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transmitting from a first satellite to a first group of ground terminals using a first number of timeslots in a TDM frame period; transmitting from said first satellite and a second satellite in alternate TDM frames to a second group of ground terminals using a second number of timeslots in said TDM frame period; and transmitting from said second satellite to a third group of ground terminals using a third number of timeslots in said TDM frame period. - View Dependent Claims (2, 3, 4, 5)
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6. Ground terminal means adapted for communicating via a plurality of orbiting satellites comprising:
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receiver means for receiving a signal transmitted in a TDM timeslot from a satellite and amplifying, filtering and converting it into numerical form for processing; timing means for adapting said receiver means to receive said TDM timeslot cyclically in different frames from each of said plurality of satellites according to a predetermined pattern; and numerical processing means for processing said converted signals received from different satellites in such a way as to reduce the effects of signal fading. - View Dependent Claims (7, 8)
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9. Timing controller means for controlling the transmit times of a plurality of satellite ground terminals in dependence on whether said transmissions are intended to be relayed by a first orbiting satellite, a second orbiting satellite or more than one orbiting satellite to avoid time overlap between transmissions from the plurality of ground terminals to the first and second orbiting satellites, comprising:
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means for dividing channels into a plurality of timeslot groups, wherein a first group of timeslots are for ground terminals communicating with the first satellite, a third group of timeslots are for ground terminals communicating with the second satellite, and a second group of timeslots are for ground terminals communicating with the first and second satellites; means for determining propagation delay of signals from ground terminals to said first and second satellites; means for assigning ground terminals from said first group that produce the greatest propagation delay increase to the second satellite compared to that of the first satellite to timeslots at the front of said first group of timeslots; and means for assigning ground terminals from said third group that produce the greatest propagation delay increases to the first satellite compared to that of the second satellite to timeslots at the front of said third group of timeslots. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method for improving radio communication service quality between a radio communications network and subscriber stations using at least two relay stations operating to provide path diversity, comprising the steps of:
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transmitting a signal burst containing a first part of an information signal using a communications channel available to a first of said at least two relay stations and transmitting a signal burst containing a second, different part of said information signal using a channel available to a second of said relay stations; and while said first relay station is transmitting a signal burst to a given subscriber station, using said available channel on said second relay station to transmit a burst to a different subscriber station and vice-versa. - View Dependent Claims (17, 18)
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19. A subscriber terminal for providing voice or data communications with a radio communications network employing path diversity, comprising:
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receiving means for receiving signal bursts alternately from a first transmitting station on a first communications channel and a second transmitting station on a second communications channel; and processing means for jointly processing information received in successive bursts comprising information transmitted by said first station and different information transmitted by said second station in order to provide an improvement in signal quality by path diversity. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
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27. Timing controller for controlling the transmit times of a plurality of satellite ground terminals in dependence on whether said transmissions are intended to be relayed by a first orbiting satellite, a second orbiting satellite or more than one orbiting satellite to avoid time overlap between transmissions from the plurality of ground terminals to the first and second orbiting satellites, comprising:
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means for distributing timeslots to ground terminals along lines of constant delta-range to said first and second satellites; and means for distributing frequencies to ground terminals-lying along lines of constant delta-Doppler.
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Specification