US5280471A
Expired / Lapsed
US
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Arrangement and method for detecting interference in TDMA communications system
Assignee: NEC Corp
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Filing: 1991-12-20
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Granted: 1994-01-18
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Expires: 2011-12-20
Abstract
Abstract Interference in a high speed receive signal is effectively detected in a TDMA communications system wherein a plurality of time slots is provided within a TDMA frame. A comparator is arranged to receive a first signal indicative of receive signal strength and a reference level signal. The comparator compares the magnitudes of the two signals applied thereto and outputs a comparison result signal. A delay circuit is supplied with a second signal indicative of a time slot which is not in use and which delays the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame. A gate circuit, preceded by the comparator and the delay circuit, is supplied with the outputs of the comparator and the delay circuit. The gate circuit outputs a third signal which changes a logic level in the event that the strength of the first signal exceeds that of the reference level signal during the time slot which is not in use.
Inventors
- 👤 Seiji Kondou
- 👤 Hiroshi Akahori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:38
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/1851; H04B7/18513; H04B7/24; H04B7/26; H04B7/2643
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
181 words
An arrangement for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising: first means arranged to receive a first signal indicative of receive signal strength and a reference level signal, the first means comparing the first signal and the reference level signal and outputting a comparison result signal; second means which is supplied with a second signal indicative of a time slot which is not in use and which delays the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and third means which is responsive to the outputs of the first and second means and which outputs a third signal, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use, wherein said predetermined time corresponds to a time duration by which a TDMA frame received is delayed as compared with a TDMA frame transmitted.
Claim 2
Dependent Claim
181 words
An arrangement for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising: first means arranged to receive a first signal indicative of receive signal strength and a reference level signal, the first means comparing the first signal and the reference level signal and outputting a comparison result signal; second means which is supplied with a second signal indicative of a time slot which is not in use and which delays the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and third means which is responsive to the outputs of the first and second means and which outputs a third signal, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use, wherein said predetermined time corresponds to a time duration by which a TDMA frame received is delayed as compared with a TDMA frame transmitted.
Claim 3
Dependent Claim
165 words
An arrangement for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising: first means arranged to receive a first signal indicative of receive signal strength and a reference level signal, the first means comparing the first signal and the reference level signal and outputting a comparison result signal; second means which is supplied with a second signal indicative of a time slot which is not in use and which delays the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and third means which is responsive to the outputs of the first and second means and which outputs a third signal, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use, wherein said third means is a logic gate.
Claim 4
Dependent Claim
165 words
An arrangement for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising: first means arranged to receive a first signal indicative of receive signal strength and a reference level signal, the first means comparing the first signal and the reference level signal and outputting a comparison result signal; second means which is supplied with a second signal indicative of a time slot which is not in use and which delays the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and third means which is responsive to the outputs of the first and second means and which outputs a third signal, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use, wherein said third means is a logic gate.
Claim 5
Dependent Claim
16 words
An arrangement as claimed in claim 2, wherein the logic gate is an exclusive OR gate.
Claim 6
Independent Claim
170 words
A method for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising the steps of: (a) receiving a first signal indicative of receive signal strength and a reference level signal, and comparing the first signal and the reference level signal and outputting a comparison result signal; (b) receiving a second signal indicative of a time slot which is not in use and delaying the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and (c) responding to the outputs of the first and second means and outputting a third signal, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use, wherein said predetermined time corresponds to a time duration by which the TDMA frame received is delayed as compared with the TDMA frame transmitted.
Claim 7
Independent Claim
170 words
A method for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising the steps of: (a) receiving a first signal indicative of receive signal strength and a reference level signal, and comparing the first signal and the reference level signal and outputting a comparison result signal; (b) receiving a second signal indicative of a time slot which is not in use and delaying the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and (c) responding to the outputs of the first and second means and outputting a third signal, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use, wherein said predetermined time corresponds to a time duration by which the TDMA frame received is delayed as compared with the TDMA frame transmitted.
Claim 8
Independent Claim
150 words
A method for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising the steps of: (a) receiving a first signal indicative of receive signal strength and a reference level signal, and comparing the first signal and the reference level signal and outputting a comparison result signal; (b) receiving a second signal indicative of a time slot which is not in use and delaying the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and (c) responding to the outputs of the first and second means and outputting a third signal by a logic gate, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use.
Claim 9
Independent Claim
150 words
A method for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame, comprising the steps of: (a) receiving a first signal indicative of receive signal strength and a reference level signal, and comparing the first signal and the reference level signal and outputting a comparison result signal; (b) receiving a second signal indicative of a time slot which is not in use and delaying the second signal by a predetermined time using a clock which is synchronized with the time slots of the TDMA frame; and (c) responding to the outputs of the first and second means and outputting a third signal by a logic gate, the third signal changing a logic level in the event that the comparison result signal exists within the time slot which is not in use.
Claim 10
Dependent Claim
50 words
A method for detecting an interference in a receive signal in a time division multiple access (TDMA) communications system wherein a plurality of time slots is provided within a TDMA frame as in claim 5, wherein said responding step includes outputting said third signal by using an exclusive OR gate.
References Cited (Backward Citations)
US5148548A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-17 | 1997-07-19 | 1998-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-17 | 2001-07-19 | 2002-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-17 | 2005-07-19 | 2006-01-18 | $7700.00 | Window Closed / Lapsed |