US3633170A
Expired / Lapsed
US
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Digital filter and threshold circuit
Assignee: International Business Machines Corp
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Filing: 1970-06-09
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Granted: 1972-01-04
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Expires: 1990-06-09
Abstract
Abstract In a data receiver binary-coded analog signal samples are applied to the delay element of a digital filter of the transversal-type. The samples are logically combined and weighted to provide a numeric digital output with reference to a threshold without analog reconversion.
Inventors
- 👤 Gardner D Jones Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:51
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03114; H04L25/03133
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
91 words
In a filter of the transversal type in which a series of pulses is applied through a delay element, such as an n stage shift register in which a preselected m of the n stages is assigned a corresponding arithmetic weighting ai, the combination comprising: means for counting in base b to an upper limit of br; and a logic arrangement for distributing the signal present at preselected ones of the shift register stages to those counter stages the sum of whose count capacity for each selected ai where q r.
Claim 2
Dependent Claim
91 words
In a filter of the transversal type in which a series of pulses is applied through a delay element, such as an n stage shift register in which a preselected m of the n stages is assigned a corresponding arithmetic weighting ai, the combination comprising: means for counting in base b to an upper limit of br; and a logic arrangement for distributing the signal present at preselected ones of the shift register stages to those counter stages the sum of whose count capacity for each selected ai where q r.
Claim 3
Dependent Claim
90 words
A digital filter comprising: an n shift stage register in which a preselected m of the n stages is assigned a corresponding arithmetic weighting ai; means for applying a pulse train to the shift register; a counter in base b having an upper limit of br; and a logic arrangement for distributing the signal present at preselected ones of the m of n shift register stages only to those counter stages the sum of whose count capacity for each selected ai where q is less than or equal to r.
Claim 4
Dependent Claim
90 words
A digital filter comprising: an n shift stage register in which a preselected m of the n stages is assigned a corresponding arithmetic weighting ai; means for applying a pulse train to the shift register; a counter in base b having an upper limit of br; and a logic arrangement for distributing the signal present at preselected ones of the m of n shift register stages only to those counter stages the sum of whose count capacity for each selected ai where q is less than or equal to r.
Claim 5
Dependent Claim
112 words
In a filter of the transversal type in which a series of binary pulses are cyclically applied to an n stage shift register and, further, in which each of m preselected stages is assigned a corresponding arithmetic weight ai, the combination comprising: a binary counter having r stages; a logic arrangement for distributing the signal present at preselected ones of the m shift register stages only to those counter stages the sum of whose count capacity for each selected ai, where q is less than or equal to r; and means coupled to the binary counter for providing signal indication if the binary signal counter magnitude is greater than a reference value.
Claim 6
Dependent Claim
112 words
In a filter of the transversal type in which a series of binary pulses are cyclically applied to an n stage shift register and, further, in which each of m preselected stages is assigned a corresponding arithmetic weight ai, the combination comprising: a binary counter having r stages; a logic arrangement for distributing the signal present at preselected ones of the m shift register stages only to those counter stages the sum of whose count capacity for each selected ai, where q is less than or equal to r; and means coupled to the binary counter for providing signal indication if the binary signal counter magnitude is greater than a reference value.
Claim 7
Dependent Claim
119 words
In a data-transmission system in which only fluctuations in signal amplitude from sampling instant to sampling instant are encoded in binary and further wherein each binary signal represents the fact that the corresponding signal magnitude exceeds the sum of the prior differences between the instant magnitude and a reference, said system comprising: an n-stage shift register; means for applying successive binary signals to the shift register; a binary counter; a logic arrangement for distributing the binary signals present at a preselected m of the n shift register stages to preselected ones of the counter stages; and means coupled to the binary counter means for providing signal indication if the binary counter signal magnitude is greater than a reference value.
Claim 8
Dependent Claim
119 words
In a data-transmission system in which only fluctuations in signal amplitude from sampling instant to sampling instant are encoded in binary and further wherein each binary signal represents the fact that the corresponding signal magnitude exceeds the sum of the prior differences between the instant magnitude and a reference, said system comprising: an n-stage shift register; means for applying successive binary signals to the shift register; a binary counter; a logic arrangement for distributing the binary signals present at a preselected m of the n shift register stages to preselected ones of the counter stages; and means coupled to the binary counter means for providing signal indication if the binary counter signal magnitude is greater than a reference value.
Claim 9
Dependent Claim
97 words
A digital filter according to claim 2, wherein the logic arrangement includes: a source of selection signals; m OR gates coupling corresponding ones of m counter stages where m is less than or equal to r; m AND gates terminating corresponding ones of the m shift register stages as a first input, each AND gate coupling only those counter stages through the associate OR gate, the sum of whose count capacity for each ai, where q is less than or equal to r; and means for activating only those AND gates corresponding to the selection signal source.
Claim 10
Dependent Claim
143 words
In a data-transmission system including a transmission medium having a nonlinear attenuation versus phase characteristic; means For impressing an analog signal upon the medium; and a receiver coupling said medium; the combination comprising: means at the receiver responsive to the analog signal for providing a delta modulated equivalence represented by a binary pulse train; an n-stage shift register; means for applying the binary pulse train to the shift register; a binary counter; a logic arrangement responsive to separately coded indicia for distributing the binary pulses present at a preselected m of the n shift register stages to preselected ones of the counter stages; and means coupled to the binary counter for providing signal indication if the binary counter signal magnitude is greater than a reference value, whereby alteration of the logic arrangement by varying the coded indicia effectively provides a linearizing phase characteristic.
Claim 11
Dependent Claim
143 words
In a data-transmission system including a transmission medium having a nonlinear attenuation versus phase characteristic; means For impressing an analog signal upon the medium; and a receiver coupling said medium; the combination comprising: means at the receiver responsive to the analog signal for providing a delta modulated equivalence represented by a binary pulse train; an n-stage shift register; means for applying the binary pulse train to the shift register; a binary counter; a logic arrangement responsive to separately coded indicia for distributing the binary pulses present at a preselected m of the n shift register stages to preselected ones of the counter stages; and means coupled to the binary counter for providing signal indication if the binary counter signal magnitude is greater than a reference value, whereby alteration of the logic arrangement by varying the coded indicia effectively provides a linearizing phase characteristic.
Claim 12
Dependent Claim
106 words
In a data-transmission system in which only fluctuations in signal amplitude from sampling instant to sampling instant are encoded in binary and further wherein each binary signal represents the fact that the corresponding signal magnitude exceeds the sum of the prior differences between the instant magnitude and a reference; said system comprising: an N-stage shift register; means for applying successive binary signals to the shift register; a weighting circuit having M-input ports; and a logic arrangement responsive to separately coded indicia for distributing the binary signals present at a preselected M of the N shift register stages to preselected and corresponding ones of the M-input ports.
Claim 13
Dependent Claim
106 words
In a data-transmission system in which only fluctuations in signal amplitude from sampling instant to sampling instant are encoded in binary and further wherein each binary signal represents the fact that the corresponding signal magnitude exceeds the sum of the prior differences between the instant magnitude and a reference; said system comprising: an N-stage shift register; means for applying successive binary signals to the shift register; a weighting circuit having M-input ports; and a logic arrangement responsive to separately coded indicia for distributing the binary signals present at a preselected M of the N shift register stages to preselected and corresponding ones of the M-input ports.
References Cited (Backward Citations)
US3315171A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |