Power control for a mobile terminal in a satellite communication system
First Claim
1. An open loop power control method for controlling the transmit power of a mobile terminal using allocated timeslots in a repetitive frame period comprising:
- receiving a signal transmitted in a first timeslot of said frame period other than the mobile terminal'"'"'s allocated timeslots, said first timeslot being a receive slot allocated for some other mobile terminal;
measuring the signal strength of the received signal;
computing a transmit power setting for the mobile terminal based on said measurement of said received signal strength to provide open loop power control; and
transmitting a signal at said computed transmit power setting in a second timeslot in said frame period, said second timeslot being allocated for the mobile terminal.
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Accused Products
Abstract
A method for controlling the transmit power level of a mobile terminal in a satellite communication system includes both a closed-loop element and an open-loop element. For the closed-loop element, the base station calculates the mobile terminal'"'"'s power setting based on the strength of the signals received from the mobile terminal. The base station takes into account the propagation delays of the satellite system in determining the mobile terminal'"'"'s transmit power setting. The open-loop element of the power control method allows the mobile terminal to adjust its own transmit power level from frame to frame based on the strength of the received signals from the base station. The strength of the signal received from the base station in each frame is compared to the strength of the signal received in the previous frame. The transmit power level of the mobile terminal is then adjusted inversely in accordance with variations in the observed signal strength.
71 Citations
22 Claims
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1. An open loop power control method for controlling the transmit power of a mobile terminal using allocated timeslots in a repetitive frame period comprising:
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receiving a signal transmitted in a first timeslot of said frame period other than the mobile terminal'"'"'s allocated timeslots, said first timeslot being a receive slot allocated for some other mobile terminal;
measuring the signal strength of the received signal;
computing a transmit power setting for the mobile terminal based on said measurement of said received signal strength to provide open loop power control; and
transmitting a signal at said computed transmit power setting in a second timeslot in said frame period, said second timeslot being allocated for the mobile terminal.
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2. A closed-loop power control method for controlling the transmit power level of a mobile terminal, said method comprising:
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receiving a transmitted signal from said mobile terminal;
measuring the signal strength of the received signal;
calculating a power deviation value based on the difference between the measured signal of said received signal and a predetermined reference power;
computing a power adjustment to the current transmit power setting for said mobile terminal based on said power deviation value and a predetermined delay factor;
wherein said adjustment is a fractional portion of said power deviation value; and
transmitting the adjusted transmit power setting to said mobile terminal. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10)
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11. An open-loop power control method for controlling the transmit power level of a mobile terminal, said method comprising:
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receiving signals transmitted to said mobile terminal in an allocated receive timeslot of a repetitive frame period for said mobile terminal;
when no signal is received in the mobile terminal'"'"'s allocated receive timeslot, switching to an alternate timeslot and receiving signals in said alternate timeslot;
measuring the signal strength of the signals received in the mobile terminal'"'"'s allocated timeslot and in the alternate timeslot;
adjusting the transmit power level of said mobile terminal based on the measured signal strength of the signal received in the mobile terminal'"'"'s own allocated receive timeslot when a signal is received therein; and
adjusting the transmit power level of said mobile terminal based on the measured signal strength of the signal received in the alternate timeslot when no signal is received in the mobile terminal'"'"'s own allocated receive timeslot. - View Dependent Claims (12, 13, 14)
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15. An open loop power control method for controlling the transmit power of a mobile terminal using timeslots in a repetitive frame period, said method comprising:
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receiving, from a remote station operating in a discontinuous transmission mode, a periodic reference signal over a control channel at a pre-determined power level known to the mobile terminal; and
varying the transmit power level of the mobile terminal over an uplink traffic channel inversely in accordance with variations in an observed strength of said periodic reference signal to provide open loop power control. - View Dependent Claims (16)
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17. A mobile terminal comprising:
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a receiver to receive a periodic reference signal over a control channel from a remote station operating in a discontinuous transmission mode, said periodic reference signal transmitted at a pre-determined power level known to the mobile terminal; and
a control unit to vary the transmit power level of the mobile terminal over an uplink traffic channel inversely in accordance with variations in an observed strength of said periodic reference signal to provide open loop power control. - View Dependent Claims (18, 19, 20)
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21. A mobile terminal comprising:
a processor programmed to control the transmit power of said mobile terminal over an uplink traffic channel responsive to variations in an observed strength of a periodic reference signal, said periodic reference signal received by the mobile terminal over a control channel at a pre determined power level from a remote station operating in a discontinuous transmission mode. - View Dependent Claims (22)
Specification