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US5072448A Expired / Lapsed US ⏱️ 0.0 years remaining

Quasi-random digital sequence detector

Assignee: Motorola Solutions Inc
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Filing: 1989-11-02
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Granted: 1991-12-10
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Expires: 2009-11-02
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Abstract

Abstract Errors in a predetermined digital sequence are detected by utilizing a detector which includes memory elements such as a series shift register, and logic gates for detecting a predetermined subsequence. Errors are detected by comparing each bit in the data stream with the output of the memory. Logic gates inhibit the detection of an error in response to the subsequence detection.

Inventors

  • 👤 Keith E. Atwell
  • 👤 Harold A. Vaghy

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 12:26
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/004; H04L1/0045; H04L1/0056; H04L1/0061

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 113 words
A detector for detecting errors in a predetermined sequence of bits in a digital data stream comprising: a) memory means for receiving and storing a plurality of bits in said data stream, said memory means having a plurality of memory elements and an output whose digital state depends on the contents of said elements; b) logic means for detecting a predetermined subsequence in said sequence based on the contents of said elements; c) means for detecting errors in said predetermined sequence by comparing each bit in said data stream with the state of said output; and d) means for inhibiting said error detecting means in response to said logic means detecting said subsequence.
Claim 2
Dependent Claim 113 words
A detector for detecting errors in a predetermined sequence of bits in a digital data stream comprising: a) memory means for receiving and storing a plurality of bits in said data stream, said memory means having a plurality of memory elements and an output whose digital state depends on the contents of said elements; b) logic means for detecting a predetermined subsequence in said sequence based on the contents of said elements; c) means for detecting errors in said predetermined sequence by comparing each bit in said data stream with the state of said output; and d) means for inhibiting said error detecting means in response to said logic means detecting said subsequence.
Claim 3
Dependent Claim 14 words
The detector according to claim 1 wherein said memory means comprises a shift register.
Claim 4
Dependent Claim 20 words
The detector according to claim 2 wherein said logic means comprises logic gates connected to stages of said shift register.
Claim 5
Dependent Claim 23 words
The detector according to claim 1 wherein said inhibiting means comprises at least one logic gate coupled to inhibit said error detecting means.
Claim 6
Dependent Claim 37 words
The detector according to claim 1 wherein said inhibiting means comprises means connected to said memory means for changing the state of a received bit before said memory means receives same upon the detection of said subsequence.
Claim 7
Dependent Claim 14 words
The detector according to claim 1 wherein said sequence is a quasi-random data sequence.
Claim 8
Dependent Claim 16 words
The detector according to claim 6 wherein said sequence comprises a quasi-random signal source (QRSS) sequence.
Claim 9
Dependent Claim 27 words
The detector according to claim 1 in which the number of said memory elements does not exceed the amount of memory utilized to generate said predetermined sequence.
Claim 10
Dependent Claim 16 words
The detector according to claim 1 wherein said memory means consecutively receives and stores said bits.
Claim 11
Independent Claim 105 words
A method of detecting errors in a predetermined sequence of bits in a digital data stream comprising the steps of: a) receiving and storing a plurality of bits in said data stream in a plurality of memory elements; b) generating an output whose digital state depends on the contents of said memory elements; c) detecting a predetermined subsequence in said sequence based on the contents of said memory elements; d) detecting errors in said predetermined sequence by comparing each bit in the data stream with the state of said output; and e) inhibiting the detecting of errors in response to the detection of said subsequence.
Claim 12
Independent Claim 105 words
A method of detecting errors in a predetermined sequence of bits in a digital data stream comprising the steps of: a) receiving and storing a plurality of bits in said data stream in a plurality of memory elements; b) generating an output whose digital state depends on the contents of said memory elements; c) detecting a predetermined subsequence in said sequence based on the contents of said memory elements; d) detecting errors in said predetermined sequence by comparing each bit in the data stream with the state of said output; and e) inhibiting the detecting of errors in response to the detection of said subsequence.
Claim 13
Dependent Claim 34 words
The method according to claim 10 wherein said sequence comprises a quasi-random sequence and wherein the number of said memory elements does not exceed the amount of memory utilized in generating said quasi-random sequence.

References Cited (Backward Citations)

USRE30037E Cited
US4271513A Cited
US4852103A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-12-09 1995-06-10 1995-12-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-12-09 1999-06-10 1999-12-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-12-09 2003-06-10 2003-12-10 $7700.00 Window Closed / Lapsed

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