US5287556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interference reduction using an adaptive receiver filter, signal strength, and BER sensing
Assignee: Motorola Solutions Inc
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Filing: 1990-09-28
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Granted: 1994-02-15
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Expires: 2010-09-28
Abstract
Abstract A radio receiver having a variable bandwidth received channel filter (113,115) to reduce interference is disclosed. A interference is detected by comparing received signal strength and received signal BER. The bandwidth of the filter (113,115) is narrowed to improve BER when a received signal strength is greater than a threshhold value and BER is worse than a threshhold value.
Inventors
- 👤 Stephen V. Cahill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:45
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/1646; H04B1/1653; H04B1/10; H04B1/1027; H04B2001/1054
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
158 words
A radio receiver having a variable bandwidth received channel filter to pass a desired signal having a plurality of time slots and reject an undesired signal, the radio receiver comprising: means for producing a first signal having a value related to the signal strength of the desired signal received by the receiver; means for determining a bit error rate of the desired signal during a first one of the plurality of time slots; means for comparing said first signal value to a predetermined threshold value and for comparing said determined bit error rate to a predetermined bit error rate and for producing an output signal when said first signal value crosses said predetermined threshold value and said determined bit error rate exceeds said predetermined bit error rate; and means, responsive to said output signal, for adjusting the bandwidth of the variable bandwidth received channel selectivity filter for passage of a second one of the plurality of time slots.
Claim 2
Dependent Claim
158 words
A radio receiver having a variable bandwidth received channel filter to pass a desired signal having a plurality of time slots and reject an undesired signal, the radio receiver comprising: means for producing a first signal having a value related to the signal strength of the desired signal received by the receiver; means for determining a bit error rate of the desired signal during a first one of the plurality of time slots; means for comparing said first signal value to a predetermined threshold value and for comparing said determined bit error rate to a predetermined bit error rate and for producing an output signal when said first signal value crosses said predetermined threshold value and said determined bit error rate exceeds said predetermined bit error rate; and means, responsive to said output signal, for adjusting the bandwidth of the variable bandwidth received channel selectivity filter for passage of a second one of the plurality of time slots.
Claim 3
Dependent Claim
38 words
A radio receiver in accordance with claim 1 wherein said means for adjusting the bandwidth of the variable bandwidth received channel selectivity filter further comprises means for reducing the bandwidth of the variable bandwidth received channel selectivity filter.
Claim 4
Dependent Claim
30 words
A radio receiver in accordance with claim 1 wherein the variable bandwidth received channel filter further comprises a variable bandwidth received channel filter having a plurality of discrete filter bandwidths.
Claim 5
Independent Claim
156 words
A method of reducing adjacent channel interference in a radio receiver having a variable bandwidth received channel filter to pass a desired signal having a plurality of time slots and to reject an undesired signal, comprising the steps of: producing a first signal having a value related to the signal strength of the desired signal received by the receiver; determining a bit error rate of the desired signal during a first one of the plurality of time slots; comparing said first signal value to a predetermined threshold value; comparing said determined bit error rate to a predetermined bit error rate; producing an output signal when said first signal value crosses said predetermined threshold value and said determined bit error rate exceeds said predetermined bit error rate; and adjusting the bandwidth of the variable bandwidth received channel selectivity filter for passage of a second one of the plurality of time slots in response to said output signal.
Claim 6
Independent Claim
156 words
A method of reducing adjacent channel interference in a radio receiver having a variable bandwidth received channel filter to pass a desired signal having a plurality of time slots and to reject an undesired signal, comprising the steps of: producing a first signal having a value related to the signal strength of the desired signal received by the receiver; determining a bit error rate of the desired signal during a first one of the plurality of time slots; comparing said first signal value to a predetermined threshold value; comparing said determined bit error rate to a predetermined bit error rate; producing an output signal when said first signal value crosses said predetermined threshold value and said determined bit error rate exceeds said predetermined bit error rate; and adjusting the bandwidth of the variable bandwidth received channel selectivity filter for passage of a second one of the plurality of time slots in response to said output signal.
Claim 7
Dependent Claim
41 words
A method in accordance with the method of claim 4 wherein said step of adjusting the bandwidth of the variable bandwidth received channel selectivity filter further comprises the step of reducing the bandwidth of the variable bandwidth received channel selectivity filter.
References Cited (Backward Citations)
US3462691A
Cited
US4135158A
Cited
US4132952A
Cited
US4549312A
Cited
US4408348A
Cited
US4573211A
Cited
US4527281A
Cited
US4459650A
Cited
US4577171A
Cited
US4510624A
Cited
US4654884A
Cited
US4595927A
Cited
US4710973A
Cited
JPS61177030A
Cited
US4736457A
Cited
US4893349A
Cited
US4792991A
Cited
US4802238A
Cited
JPS63194423A
Cited
US4998289A
Cited
US5001776A
Cited
EP0369465A2
Cited
JPH02194736A
Cited
US5012490A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-14 | 1997-08-16 | 1998-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-14 | 2001-08-16 | 2002-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-14 | 2005-08-16 | 2006-02-15 | $7700.00 | Window Closed / Lapsed |