Patent US5491726A successfully refreshed from Google Patents.
US5491726A
Expired / Lapsed
US
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Method and apparatus to determine the frequency and time slot position in a digital wireless communication session
Assignee: Sharp Corp
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Filing: 1993-08-17
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Granted: 1996-02-13
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Expires: 2013-08-17
Abstract
Abstract A digital wireless communication system operates between a first unit and a second unit. The received digitally encoded signal is sampled to produce a first sampled digital signal. A first bank of match filters with each match filter having a different frequency range is used to pass the first sampled digital signal therethrough. The output of the first bank of match filters having the largest amplitude is selected along with the match filter which produced the largest amplitude output. The digitally encoded signal having this "coarse" frequency range is then passed through a second bank of match filters. Each of the match filters has a fine frequency different from one another. The output of the second bank of match filters is produced and the output having the largest amplitude is selected. In addition, the filter producing the largest amplitude from the second bank of match filters is also selected.
Inventors
- 👤 Jong-Keung Cheng
- 👤 Nan-Sheng Lin
- 👤 Mihran H. Touriguian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:12
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/02; H04L7/033; H04L7/0334; G; G01; G01S; G01S11/00; G01S11/02; G01S11/10; H04L7/04; H04L7/041; H04L7/042
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
244 words
A digital wireless communication system for communicating between a first unit and a second unit, wherein said first unit transmits a digitally encoded signal at a first frequency, and wherein said transmission is subject to deviation in frequency upon arrival at said second unit, said second unit comprising: antenna means for receiving said digitally encoded signal; means for sampling said digitally encoded signal to produce a first sampled digital signal; a plurality of first digital filter means for receiving said first sampled digital signal simultaneously, each of said first digital filter means being a match filter tuned to a frequency range different from one another for producing a plurality of second sampled digital signals with each having an amplitude; means for receiving said plurality of second sampled digital signals and for selecting the second sampled digital signal with the largest amplitude, and for selecting the first digital filter means producing said selected second sampled digital signal; a plurality of second digital filter means for receiving said selected second sampled digital signal simultaneously, each of said second digital filter means being a match filter tuned to a frequency range different from one another for producing a plurality of third sampled digital signals with each having an amplitude; and means for receiving said plurality of third sampled digital signals and for selecting the third sampled digital signal with the largest amplitude and for selecting the second digital filter means producing said selected third sampled digital signal.
Claim 2
Dependent Claim
244 words
A digital wireless communication system for communicating between a first unit and a second unit, wherein said first unit transmits a digitally encoded signal at a first frequency, and wherein said transmission is subject to deviation in frequency upon arrival at said second unit, said second unit comprising: antenna means for receiving said digitally encoded signal; means for sampling said digitally encoded signal to produce a first sampled digital signal; a plurality of first digital filter means for receiving said first sampled digital signal simultaneously, each of said first digital filter means being a match filter tuned to a frequency range different from one another for producing a plurality of second sampled digital signals with each having an amplitude; means for receiving said plurality of second sampled digital signals and for selecting the second sampled digital signal with the largest amplitude, and for selecting the first digital filter means producing said selected second sampled digital signal; a plurality of second digital filter means for receiving said selected second sampled digital signal simultaneously, each of said second digital filter means being a match filter tuned to a frequency range different from one another for producing a plurality of third sampled digital signals with each having an amplitude; and means for receiving said plurality of third sampled digital signals and for selecting the third sampled digital signal with the largest amplitude and for selecting the second digital filter means producing said selected third sampled digital signal.
Claim 3
Dependent Claim
14 words
The system of claim 1 wherein said first unit is a stationary base station.
Claim 4
Dependent Claim
13 words
The system of claim 2 wherein said second unit is a mobile unit.
Claim 5
Dependent Claim
18 words
The system of claim 1 wherein said first unit transmits said digitally encoded signal in a TDMA mode.
Claim 6
Dependent Claim
22 words
The system of claim 1 wherein said digitally encoded signal is subject to sampling phase error upon arrival at said second unit.
Claim 7
Dependent Claim
19 words
The system of claim 5 wherein said digitally encoded signal is a digital signal encoded at a first rate.
Claim 8
Dependent Claim
22 words
The system of claim 6 wherein said sampling means samples said digitally encoded signal at a rate faster than said first rate.
Claim 9
Dependent Claim
220 words
A digital wireless communication method between a first unit and a second unit, wherein said first unit transmits a digitally encoded signal at a first frequency, and wherein said transmission is subject to deviation in frequency upon arrival at said second unit, said method comprising: receiving said digitally encoded signal by said second unit; sampling said digitally encoded signal by said second unit to produce a first sampled digital signal; supplying said first sampled digital signal to a plurality of first digital filter means simultaneously, with each of said first digital filter means being a match filter tuned to a frequency range different from one another, to produce a plurality of second sampled digital signals with each having an amplitude; selecting the second sampled digital signal having the largest amplitude and selecting the first digital filter means producing the selected second sampled digital signal; supplying said selected second sampled digital signal to a plurality of second digital filter means simultaneously, with each of said second digital filter means being a match filter tuned to a frequency range different from one another, to produce a plurality of third sampled digital signals with each having an amplitude; and selecting the third sampled digital signal having the largest amplitude and selecting the second digital filter means producing the selected third sampled digital signal.
Claim 10
Dependent Claim
220 words
A digital wireless communication method between a first unit and a second unit, wherein said first unit transmits a digitally encoded signal at a first frequency, and wherein said transmission is subject to deviation in frequency upon arrival at said second unit, said method comprising: receiving said digitally encoded signal by said second unit; sampling said digitally encoded signal by said second unit to produce a first sampled digital signal; supplying said first sampled digital signal to a plurality of first digital filter means simultaneously, with each of said first digital filter means being a match filter tuned to a frequency range different from one another, to produce a plurality of second sampled digital signals with each having an amplitude; selecting the second sampled digital signal having the largest amplitude and selecting the first digital filter means producing the selected second sampled digital signal; supplying said selected second sampled digital signal to a plurality of second digital filter means simultaneously, with each of said second digital filter means being a match filter tuned to a frequency range different from one another, to produce a plurality of third sampled digital signals with each having an amplitude; and selecting the third sampled digital signal having the largest amplitude and selecting the second digital filter means producing the selected third sampled digital signal.
Claim 11
Dependent Claim
16 words
The method of claim 8 further comprising transmitting said digitally encoded signal in a TDMA mode.
Claim 12
Dependent Claim
16 words
The method of claim 9 further comprising receiving said digitally encoded signal in said TDMA mode.
Claim 13
Dependent Claim
235 words
A digital cellular communication system for communicating between a mobile unit and a first base station unit with each transmitting a digitally encoded signal at a frequency to the other, each of said units comprising: antenna means for receiving the digitally encoded signal transmitted by the other unit; means for sampling said digitally encoded signal to produce a first sampled digital signal; a plurality of first digital filter means for receiving said first sampled digital signal simultaneously, each of said first digital filter means being a match filter tuned to a frequency range different from one another for producing a plurality of second sampled digital signals with each having an amplitude; means for receiving said plurality of second sampled digital signals and for selecting the second sampled digital signal with the largest amplitude, and for selecting the first digital filter means producing said selected second sampled digital signal; a plurality of second digital filter means for receiving said selected second sampled digital signal simultaneously, each of said second digital filter means being a match filter tuned to frequency range different from one another for producing a plurality of third sampled digital signals with each having an amplitude; and means for receiving said plurality of third sampled digital signals and for selecting the third sampled digital signal with the largest amplitude and for selecting the second digital filter means producing said selected third sampled digital signal.
Claim 14
Dependent Claim
235 words
A digital cellular communication system for communicating between a mobile unit and a first base station unit with each transmitting a digitally encoded signal at a frequency to the other, each of said units comprising: antenna means for receiving the digitally encoded signal transmitted by the other unit; means for sampling said digitally encoded signal to produce a first sampled digital signal; a plurality of first digital filter means for receiving said first sampled digital signal simultaneously, each of said first digital filter means being a match filter tuned to a frequency range different from one another for producing a plurality of second sampled digital signals with each having an amplitude; means for receiving said plurality of second sampled digital signals and for selecting the second sampled digital signal with the largest amplitude, and for selecting the first digital filter means producing said selected second sampled digital signal; a plurality of second digital filter means for receiving said selected second sampled digital signal simultaneously, each of said second digital filter means being a match filter tuned to frequency range different from one another for producing a plurality of third sampled digital signals with each having an amplitude; and means for receiving said plurality of third sampled digital signals and for selecting the third sampled digital signal with the largest amplitude and for selecting the second digital filter means producing said selected third sampled digital signal.
Claim 15
Dependent Claim
20 words
The system of claim 11 wherein each unit transmits digitally encoded signal to the other in non-contiguous slots of time.
Claim 16
Dependent Claim
17 words
The system of claim 11 wherein each unit initially transmits synchronization data signal followed by data signal.
Claim 17
Dependent Claim
33 words
The system of claim 13 wherein said first and second digital filter means are selected during the receipt of the synchronization data signal and for the data signal following said synchronization data signal.
Claim 18
Dependent Claim
22 words
The system of claim 13 wherein said digitally encoded signal is subject to sampling phase error upon arrival at said second unit.
Claim 19
Dependent Claim
19 words
The system of claim 15 wherein said digitally encoded signal is a digital signal encoded at a first rate.
Claim 20
Dependent Claim
22 words
The system of claim 16 wherein said sampling means samples said digitally encoded signal at a rate faster than said first rate.
References Cited (Backward Citations)
US4466108A
Cited
US4558460A
Cited
US4947409A
Cited
US5027432A
Cited
US5012491A
Cited
US4879728A
Cited
US5018166A
Cited
US5040192A
Cited
US5274670A
Cited
US5287388A
Cited
US5263026A
Cited
US5268647A
Cited
US5272446A
Cited
US5276706A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-02-12 | 1999-08-14 | 2000-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-02-12 | 2003-08-14 | 2004-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-02-12 | 2007-08-14 | 2008-02-13 | $7700.00 | Window Closed / Lapsed |