Patent US5377224A successfully refreshed from Google Patents.
US5377224A
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US
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Acquisition of frequency bursts in PCN
Assignee: Apple Inc
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Filing: 1993-10-07
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Granted: 1994-12-27
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Expires: 2013-10-07
Abstract
Abstract A method of acquiring frequency bursts in a PCN broadcast control channel, including the steps of: i) sampling PCN r.f. signals for successive blocks of time of duration of half the duration of a frequency burst; ii) determining the first block to have a spectrum level to exceed a threshold value, iii) comparing the spectrum levels of said first block and an adjacent block during successive occurrences of the frequency burst; and iv) adjusting the timing of the two blocks until the spectrum levels of the two blocks are substantially equal.
Inventors
- 👤 John E. Hudson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:05
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2643
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
96 words
A method of acquiring frequency bursts in a personal communication network (PCN) broadcast control channel including the steps of: i) sampling PCN radio frequency (r.f.) signals for successive blocks of time of duration of half the duration of a frequency burst; ii) determining the first block to have a spectrum level to exceed a threshold value, iii) comparing the spectrum levels of said first block and an adjacent block during successive occurrences of the frequency burst; and iv) adjusting the timing of the two blocks until the spectrum levels of the two blocks are substantially equal.
Claim 2
Independent Claim
96 words
A method of acquiring frequency bursts in a personal communication network (PCN) broadcast control channel including the steps of: i) sampling PCN radio frequency (r.f.) signals for successive blocks of time of duration of half the duration of a frequency burst; ii) determining the first block to have a spectrum level to exceed a threshold value, iii) comparing the spectrum levels of said first block and an adjacent block during successive occurrences of the frequency burst; and iv) adjusting the timing of the two blocks until the spectrum levels of the two blocks are substantially equal.
Claim 3
Independent Claim
170 words
A method of acquiring frequency bursts in a personal communication network (PCN) broadcast control channel, including the steps of: i) sampling at a first rate a group of channels having different known frequencies for successive blocks of time of a duration of half the duration of a frequency burst; ii) performing a digital discrete Fourier transform (DFT) filter operation on the signal samples in each block; iii) comparing the peak spectrum level of each DFT filtered sample with a predetermined threshold value to determine the first block to have a spectrum level to exceed the threshold value; iv) comparing the spectrum levels of said first block and an adjacent block repetitively substantially on successive occurrences of the frequency burst to derive a differential of the spectrum levels; v) generating an error signal representing the differential of the spectrum levels; and (vi) applying said error signal in a feedback loop to adjust the sampling times of said first and adjacent blocks to drive the differential of the spectrum levels to zero.
Claim 4
Independent Claim
170 words
A method of acquiring frequency bursts in a personal communication network (PCN) broadcast control channel, including the steps of: i) sampling at a first rate a group of channels having different known frequencies for successive blocks of time of a duration of half the duration of a frequency burst; ii) performing a digital discrete Fourier transform (DFT) filter operation on the signal samples in each block; iii) comparing the peak spectrum level of each DFT filtered sample with a predetermined threshold value to determine the first block to have a spectrum level to exceed the threshold value; iv) comparing the spectrum levels of said first block and an adjacent block repetitively substantially on successive occurrences of the frequency burst to derive a differential of the spectrum levels; v) generating an error signal representing the differential of the spectrum levels; and (vi) applying said error signal in a feedback loop to adjust the sampling times of said first and adjacent blocks to drive the differential of the spectrum levels to zero.
Claim 5
Dependent Claim
53 words
A method according to claim 2 further including the steps of initially down converting the PCN r.f. signals to baseband, performing a first sampling of the baseband signals at a second rate higher than said first rate and digitally filtering said sampled baseband signals prior to performing said sampling at said first rate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |