US5903554A
Expired / Lapsed
US
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Method and apparatus for measuring link quality in a spread spectrum communication system
Assignee: Qualcomm Inc
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Filing: 1996-09-27
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Granted: 1999-05-11
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Expires: 2016-09-27
Abstract
Abstract The present invention is a method and apparatus for providing a received signal quality metric which is optimally designed to control the transmission power of a transmitter in a closed loop power control system. The present invention is described in the context of a spread spectrum communication system but it is equally applicable to other types of communication systems. In the present invention, the power control system is described for controlling the power of transmissions from a base station to a mobile station, referred to as forward link transmissions.
Inventors
- 👤 Keith W. Saints
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:16
CPC Classifications
H; H04; H04W; H04W52/00; H04W52/04; H04W52/06; H04W52/08; H04B; H04B7/00; H04B7/005; H04W52/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
108 words
In a closed loop power control system in a CDMA communication system, a method for generating power control commands comprising the steps of: measuring an inband energy value; measuring a pilot channel energy; scaling said pilot channel energy in accordance with a pilot fraction value to provide a non interfering energy value; subtracting said non interfering energy value from said inband energy value to provide an interference noise value; measuring a bit energy of a received signal; computing a signal to noise ratio in accordance with said interference noise value and said bit energy; and generating a power control command in accordance with said signal to noise ratio.
Claim 2
Dependent Claim
108 words
In a closed loop power control system in a CDMA communication system, a method for generating power control commands comprising the steps of: measuring an inband energy value; measuring a pilot channel energy; scaling said pilot channel energy in accordance with a pilot fraction value to provide a non interfering energy value; subtracting said non interfering energy value from said inband energy value to provide an interference noise value; measuring a bit energy of a received signal; computing a signal to noise ratio in accordance with said interference noise value and said bit energy; and generating a power control command in accordance with said signal to noise ratio.
Claim 3
Dependent Claim
21 words
The method of claim 1 further comprising the step of comparing said signal to noise ratio with a predetermined threshold value.
Claim 4
Dependent Claim
20 words
The method of claim 1 further comprising the step of receiving said pilot fraction value from a remote communications device.
Claim 5
Dependent Claim
35 words
The method of claim 1 wherein said step of measuring said bit energy comprises the steps of: measuring a symbol energy value; and scaling said symbol energy value in accordance with a data rate value.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein said step of measuring said bit energy comprises the steps of determining said data rate value.
Claim 7
Dependent Claim
27 words
The method of claim 4 wherein said step of measuring said bit energy comprises the steps of receiving said data rate value from a remote communication device.
Claim 8
Dependent Claim
185 words
In a closed loop power control system in a CDMA communication system, a method for generating power control commands comprising the steps of: accumulating a predetermined integer number (N) samples of a demodulated signal; computing a noise value for said demodulated signal in accordance with said accumulated samples; measuring a bit energy for said demodulated signal; computing a signal to noise ratio for said demodulated signal in accordance with said noise value for said demodulated signal and said bit energy for said demodulated signal; and generating a power control command in accordance with said signal to noise ratio: wherein said step of computing a noise value for said demodulated signal comprises the steps of: summing the squares of symbol amplitudes of said accumulated symbols to provide a summed energy value: summing the symbol amplitudes of said accumulated symbols: squaring said sum of said symbol amplitudes; dividing the square of said sum of said symbol amplitudes by N to provide a normalized square value; and subtracting said normalized square value from said summed energy value and dividing the result by (N-1) to provide said noise value.
Claim 9
Dependent Claim
185 words
In a closed loop power control system in a CDMA communication system, a method for generating power control commands comprising the steps of: accumulating a predetermined integer number (N) samples of a demodulated signal; computing a noise value for said demodulated signal in accordance with said accumulated samples; measuring a bit energy for said demodulated signal; computing a signal to noise ratio for said demodulated signal in accordance with said noise value for said demodulated signal and said bit energy for said demodulated signal; and generating a power control command in accordance with said signal to noise ratio: wherein said step of computing a noise value for said demodulated signal comprises the steps of: summing the squares of symbol amplitudes of said accumulated symbols to provide a summed energy value: summing the symbol amplitudes of said accumulated symbols: squaring said sum of said symbol amplitudes; dividing the square of said sum of said symbol amplitudes by N to provide a normalized square value; and subtracting said normalized square value from said summed energy value and dividing the result by (N-1) to provide said noise value.
Claim 10
Dependent Claim
26 words
The method of claim 7 further comprising the step of combining at least one additional signal to noise ratio for at least one additional demodulated signal.
References Cited (Backward Citations)
US5416797A
Cited
US5245629A
Cited
US5396516A
Cited
US5559790A
Cited
US5548808A
Cited
US5603096A
Cited
WO1996004718A1
Cited
US5577025A
Cited
US5721754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-05-10 | 2002-11-09 | 2003-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-10 | 2006-11-09 | 2007-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-10 | 2010-11-09 | 2011-05-11 | $7700.00 | Window Closed / Lapsed |