Closed-loop power control apparatus for mobile satellite communication system and method thereof
AssigneeElectronics and Telecommunications Research Institute
InventorsKwon-Hue Choi, Kwang-Jae Lim, Soo-Young Kim
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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.
Claims26
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.
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:
- 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.
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:
- 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.
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:
- 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.
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:
- 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.
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:
- 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.
Dependencies are inferred from the claim text.