Uplink power control mechanism for maintaining constant output p

Telecommunications – Carrier wave repeater or relay system – Monitoring

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

455 52, H04B 160

Patent

active

049411993

ABSTRACT:
Compensation for rain fades in a VSAT communications network is obtained by a uplink power control mechanism incorporated in a master station, which maintains the power output level of the satellite transponder constant without incorporating excessive static margins into the link power budget. A variable attenuator, which controls the output power of the master station's high power amplifier is initially set at a prescribed level which will produce the intended satellite amplifier EIRP for a `clear sky` condition. The master station monitors the output of the satellite amplifier and derives a measure of the signal-to-noise ratio of downlinked signals. Knowing the variable attenuator setting and the signal-to-noise ratio of the downlinked signals, the magnitude of attenuation of outlink carrier frequency signals transmitted from the master station to the satellite is determined. In the event of a rain fade, the setting of the variable attenuator is adjusted by an amount that compensates for the fade and thereby causes outlink carrier frequency signals conveyed by the satellite amplifier device to remain effectively constant. An estimate of the error in the attenuator setting is preferably derived in accordance with the ratio of the difference between the squared (I) and (Q) channel values ((S+N).sup.2 -N.sup.2) to the square of the quadrature channel-derived noise value N.sup.2 of a Costas loop in the master station's receiver.

REFERENCES:
patent: 4301533 (1981-11-01), Acampora et al.
patent: 4731866 (1988-03-01), Muratani et al.
patent: 4752967 (1988-06-01), Bustamante et al.
patent: 4776035 (1988-10-01), Duggan
"Closed-Loop Transmitting Power Control System for K-Band Satellite Communications," EGAMI, 1983, IEEE, vol. AES-19, No. 4.
"Prediction of Attenuation by Rain," Crane, 1980 IEEE, vol. COM-28, No. 9.
"Communications Satellite Systems," Martin, 1978.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Uplink power control mechanism for maintaining constant output p does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Uplink power control mechanism for maintaining constant output p, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Uplink power control mechanism for maintaining constant output p will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1725623

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.