Closed-loop power control apparatus for mobile satellite communication system and method thereof
First Claim
1. A closed-loop power control apparatus that can compensate for round trip delay (RTD) in an up-link satellite channel of a satellite Code Division Multiple Access (SAT-CDMA) mobile communication system, the apparatus comprising:
- a power control level determining means for determining a power control level based on a power control command transmitted from a base station;
a channel variation rate estimation means for estimating a channel variation rate based on received power of a pilot channel;
a filter coefficient generation means for generating a filter coefficient by using the channel variation rate;
a compensation means for receiving the power control level and compensating for the channel variation caused by the round trip delay; and
a transmit power updating means for updating transmit power by using the power control level received from the compensation means.
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Accused Products
Abstract
Apparatus and method for closed-loop power control in mobile satellite communication system, which can compensate round trip delay. The apparatus for closed-loop power control includes the means of; a) converting power control order from base earth station into power control step; b) measuring channel change rate from power of pilot channel; c) making tab coefficient using said channel change rate; d) compensating channel change due to loop delay using power control step; and e) renovating received signal power using said power control step.
24 Citations
26 Claims
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1. A closed-loop power control apparatus that can compensate for round trip delay (RTD) in an up-link satellite channel of a satellite Code Division Multiple Access (SAT-CDMA) mobile communication system, the apparatus comprising:
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a power control level determining means for determining a power control level based on a power control command transmitted from a base station; a channel variation rate estimation means for estimating a channel variation rate based on received power of a pilot channel; a filter coefficient generation means for generating a filter coefficient by using the channel variation rate; a compensation means for receiving the power control level and compensating for the channel variation caused by the round trip delay; and a transmit power updating means for updating transmit power by using the power control level received from the compensation means. - View Dependent Claims (2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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3. A closed-loop power control apparatus that can compensate for round trip delay (RTD) in a down-link satellite channel of a SAT-CDMA mobile communication system, the apparatus comprising:
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a power error computing means for calculating a power error of a received signal; a channel variation rate estimation means for estimating a channel variation rate based on received power of a pilot channel; a filter coefficient generation means for generating a filter coefficient by using the channel variation rate; a channel variation amount estimation means for estimating a channel variation amount after a loop delay time; a power error compensation means for compensating for the power error by using the output of the channel variation rate estimation means; and a power control command generation means for generating a power control command based on the compensated power error. - View Dependent Claims (4)
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20. A closed-loop power control method that can compensate for round trip delay (RTD) in an up-link satellite channel of a SAT-CDMA mobile communication system, the method comprising the steps of:
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a) receiving power of a pilot channel and a power control command; b) estimating a channel variation rate from the pilot channel power and generating a filter coefficient based on the channel variation rate; and c) compensating transmit power by using the filter coefficient. - View Dependent Claims (21)
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22. A closed-loop power control method that can compensate for round trip delay (RTD) in a down-link satellite channel of a SAT-CDMA mobile communication system, the method comprising the steps of:
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a) receiving power of a pilot channel and a signal-to-interference ratio of a received signal; b) estimating a channel variation rate based on the pilot channel power and generating a filter coefficient based on the channel variation rate; and c) compensating a power error based on the filter coefficient. - View Dependent Claims (23, 24)
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25. A computer-readable recording medium for recording a program that implements a closed-loop power control method which can compensate for round trip delay in an up-link satellite channel of a SAT-CDMA mobile communication system, the method comprising the steps of:
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a) receiving power of a pilot channel and a power control command; b) estimating a channel variation rate from the pilot channel power and generating a filter coefficient based on the channel variation rate; and c) compensating transmit power by using the filter coefficient.
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26. A computer-readable recording medium provided with a processor for recording a program that implements a closed-loop power control method which can compensate for round trip delay in a down-link satellite channel of a SAT-CDMA mobile communication system, the method comprising the steps of:
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a) receiving power of a pilot channel and a signal-to-interference ratio of a received signal; b) estimating a channel variation rate from the pilot channel power and generating a filter coefficient based on the channel variation rate; and c) compensating a power error based on the filter coefficient.
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Specification