US3723982A
Expired / Lapsed
US
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System for transmission, storage and/or multiplexing of information
Assignee: General Dynamics Corp
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Filing: 1971-02-02
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Granted: 1973-03-27
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Expires: 1991-02-02
Abstract
Abstract A system is described for transmission, storage (as by recording) and for multiplexing of both digital and analog information. The recording system includes apparatus for converting analog information into digital information having a predetermined format. Each track of the recording apparatus receives a series of encoded format words containing a plurality of ternary NRZ pulses, each represented by any one of three voltage levels; positive, negative or zero volts during a bit interval, such that the average level of each word is zero volts. The spectrum of a signal composed of a serial sequence of these format words is capable of being recorded on a magnetic tape recording track with a much higher pulse packing density than heretofore possible with conventional NRZ or other binary recording techniques. The playback apparatus which forms part of the recording system includes circuitry responsive to the zero average property of the recorded words, and controls the timing of the readout of the recorded information so as to provide precise time coherence between all of the recorded channels. The latter circuitry also controls the system for deskewing the signals recorded simultaneously on parallel tracks on the tape during playback, thereby further enhancing the capability of this system to record information with extremely high pulse packing density. Both recording and playback is controlled by a common accurate clock so as to further insure coherence between signals recorded on all channels. Also included in the recording system is an input/output section which translates input analog information into digital form for recording in the various channels at rates and with the format compatible for recording with the system. The input/output section also rearranges the digital information read from the magnetic record into its original analog or digital form, as the case may be.
Inventors
- 👤 W Frazier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:57
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/10009; G11B20/10046; G11B20/10194; G11B20/24; G11C; G11C21/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
94 words
A data recording system for analog and direct digital data signals which occur simultaneously comprising a. a high density digital recorder, b. a source of clock signals, c. means responsive to said clock signals for sampling analog signals to provide a plurality of sample signals, d. analog-to-digital converter means responsive to said clock signals and said sample signals for developing a digitized output, and e. digital signal multiplexer means responsive to said digitized output and to direct signals for interspersing them to provide a serial stream of digital data to said high density recorder.
Claim 2
Dependent Claim
94 words
A data recording system for analog and direct digital data signals which occur simultaneously comprising a. a high density digital recorder, b. a source of clock signals, c. means responsive to said clock signals for sampling analog signals to provide a plurality of sample signals, d. analog-to-digital converter means responsive to said clock signals and said sample signals for developing a digitized output, and e. digital signal multiplexer means responsive to said digitized output and to direct signals for interspersing them to provide a serial stream of digital data to said high density recorder.
Claim 3
Dependent Claim
84 words
The invention as set forth in claim 1 including a playback apparatus comprising f. demultiplexer means responsive to a stream of data from said recorder and said clock signal to provide a stream of said direct digital data and a stream of said digitized data, g. digital-to-analog converter means responsive to said digitized data stream and said clock signal for providing a plurality of analog sample signals, and h. means responsive to said clock signal and said analog sample to reconstruct an analog signal.
Claim 4
Dependent Claim
113 words
Apparatus for digitizing an analog signal comprising, a. means for sampling said analog signal for producing analog samples, b. a linear analog-to-digital converter operable within a predetermined dynamic range for producing a coded characteristic signal in response to each of said analog samples, c. means for sampling the envelope component of said analog signal, d. a logarithmic analog-to-digital converter responsive to said envelope component samples for producing a coded exponential signal, and e. gain control means responsive to said coded exponential signal for operating upon said analog samples scaling them to be within said range of said linear analog-to-digital converter whereby a digitized analog sample is represented by said first and second signals.
Claim 5
Dependent Claim
113 words
Apparatus for digitizing an analog signal comprising, a. means for sampling said analog signal for producing analog samples, b. a linear analog-to-digital converter operable within a predetermined dynamic range for producing a coded characteristic signal in response to each of said analog samples, c. means for sampling the envelope component of said analog signal, d. a logarithmic analog-to-digital converter responsive to said envelope component samples for producing a coded exponential signal, and e. gain control means responsive to said coded exponential signal for operating upon said analog samples scaling them to be within said range of said linear analog-to-digital converter whereby a digitized analog sample is represented by said first and second signals.
Claim 6
Dependent Claim
60 words
The invention as set forth in claim 3 wherein said linear analog-to-digital converter has a fixed number of bits m with at least one bit being assigned to determine the polarity of the input analog signal and the remaining m-1 bits being used to represent the amplitude of the analog component relationship, R 100 X 2(1 m) as a percentage.
Claim 7
Dependent Claim
38 words
The invention as set forth in claim 4 wherein said exponential signal has n bits selected so that the dynamic range D of said apparatus is in accordance with the following relationship: D 6(2n + m -2) Db.
Claim 8
Dependent Claim
29 words
The invention as set forth in claim 5 wherein said gain control means presents linearly related values of attenuation corresponding to the binary value of said coded exponential signal.
Claim 9
Dependent Claim
24 words
The invention as set forth in claim 3 including a commutator for sampling said exponential signal at a slower rate than said characteristic signal.
Claim 10
Dependent Claim
67 words
The invention as set forth in claim 7 including means providing storage for each of said coded signals during a period corresponding to the differences in rates of commutators and means for applying to said gain control means the stored coded exponent corresponding to the sample of said analog signal the like position in the commutation cycle until a successive coded exponent for that position is generated.
Claim 11
Dependent Claim
70 words
Apparatus for converting digital signals having coded exponential and characteristic components into their corresponding analog signals comprising a commutator for separating said exponential and characteristic components of said signals, a linear digital-to-analog converter responsive to said characteristic component for providing analog sample outputs, and gain controlled amplifier means responsive to said exponential component for varying the dynamic range of said analog sample produced at the output of said digital-to-analog converter.
Claim 12
Dependent Claim
70 words
Apparatus for converting digital signals having coded exponential and characteristic components into their corresponding analog signals comprising a commutator for separating said exponential and characteristic components of said signals, a linear digital-to-analog converter responsive to said characteristic component for providing analog sample outputs, and gain controlled amplifier means responsive to said exponential component for varying the dynamic range of said analog sample produced at the output of said digital-to-analog converter.
Claim 13
Dependent Claim
24 words
The invention as set forth in claim 9 including means responsive to a plurality of gain adjusted analog samples for reconstructing said analog signal.
Claim 14
Dependent Claim
92 words
Method of digitizing an analog signal comprising a. developing a digital exponential signal representative of the amplitude of the envelope component of said analog signal at a sample position, b. taking the amplitude sample of said analog signal at said sample position, c. adjusting said analog sample in accordance with said exponential signal so as to be within the dynamic range of an analog-to-digital converter, and d. applying said analog adjusted sample to said converter for developing a second digital signal whereby said exponential and second digital signals represent said analog sample.
Claim 15
Dependent Claim
92 words
Method of digitizing an analog signal comprising a. developing a digital exponential signal representative of the amplitude of the envelope component of said analog signal at a sample position, b. taking the amplitude sample of said analog signal at said sample position, c. adjusting said analog sample in accordance with said exponential signal so as to be within the dynamic range of an analog-to-digital converter, and d. applying said analog adjusted sample to said converter for developing a second digital signal whereby said exponential and second digital signals represent said analog sample.
Claim 16
Dependent Claim
123 words
The invention as set forth in claim 2 wherein a. said analog to digital converter means includes a linear analog-to-digital converter operable within a predetermined dynamic range for producing a coded characteristic signal in response to each of said analog samples, b. said sampling means includes means for sampling the envelope component of said analog signal, c. said analog to digital converter means further includes a logarithmic analog-to-digital converter responsive to said envelope component samples for producing a coded exponential signal, and d. gain control means responsive to said coded exponential signal for operating upon said analog samples scaling them to be within said range of said linear analog-to-digital converter whereby a digitized analog sample is represented by said first and second signals.
Claim 17
Dependent Claim
61 words
The invention as set forth in claim 12 wherein said linear analog-to-digital converter has a fixed number of bits m with at least one bit being assigned to determine the polarity of the input analog signal and the remaining m-1 bits being used to represent the amplitude of the analog component relationship, R 100 X 2 (1 m) as a percentage.
Claim 18
Dependent Claim
38 words
The invention as set forth in claim 13 wherein said exponential signal has n bits selected so that the dynamic range D of said apparatus is in accordance with the following relationship D 6(2n + m -2) Db.
Claim 19
Dependent Claim
29 words
The invention as set forth in claim 14 wherein said gain control means presents linearly related values of attenuation corresponding to the binary value of said coded exponential signal.
Claim 20
Dependent Claim
24 words
The invention as set forth in claim 12 including a commutator for sampling said exponential signal at a slower rate than said characteristic signal.
Claim 21
Dependent Claim
67 words
The invention as set forth in claim 16 including means providing storage for each of said coded signals during a period corresponding to the differences in rates of commutators and means for applying to said gain control means the stored coded exponent corresponding to the sample of said analog signal the like position in the commutation cycle until a successive coded exponent for that position is generated.
Claim 22
Dependent Claim
82 words
The invention as set forth in claim 2 wherein said digital-to-analog converter means includes means for converting digital signals having coded exponential and characteristic components into their corresponding analog signals comprising a commutator for separating said exponential and characteristic components of signals, a linear digital-to-analog converter responsive to said characteristic component for providing analog sample outputs, gain controlled amplifier means responsive to said exponential component for varying the dynamic range of said analog sample produced at the output of said digital-to-analog converter.
Claim 23
Dependent Claim
24 words
The invention as set forth in claim 18 including means responsive to a plurality of gain adjusted analog samples for reconstructing said analog signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |