US3582879A
Expired / Lapsed
US
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Communication channel equalization system and equalizer
Assignee: Computer Mode Corp
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Filing: 1969-04-25
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Granted: 1971-06-01
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Expires: 1989-04-25
Abstract
Abstract Compensating distortion of received signals is accomplished in the system. A duplicate of the transmitter error correction code encoder is used to reconstruct the transmitted signals which are then compared with the received signals to generate the equalization control signals. The fourier transform of the received signals is divided by the fourier transform of the equalization control signals to generate the fourier transform of the equalized signals which is then inverse transformed.
Inventors
- 👤 Herbert Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:23
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/14; H04B3/141
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
A system for compensating error correction encoded digital signals for distortion induced therein by the communication channel over which the signals are transmitted comprising in combination: a. an equalizer circuit including means receiving said transmitted digital signals and modifying the characteristics thereof in accordance with system generated equalizer control signals; b. a decoder having stored therein the error correction code employed in error correction encoding said transmitted digital signals and including means receiving said modified digital signals, detecting error code bits and data bits therein, correcting said data bits in accordance with said error correction code, and generating corrected data signals; c. an encoder having stored therein said error correction code and including means receiving said corrected data signals, and error correction encoding same; and d. a comparator including means receiving said modified digital signals from said equalizer and said error correction encoded corrected data signals from said encoder, detecting differences therebetween and generating signals indicative of said differences, said difference signals constituting said equalizer control signals.
Claim 2
Independent Claim
167 words
A system for compensating error correction encoded digital signals for distortion induced therein by the communication channel over which the signals are transmitted comprising in combination: a. an equalizer circuit including means receiving said transmitted digital signals and modifying the characteristics thereof in accordance with system generated equalizer control signals; b. a decoder having stored therein the error correction code employed in error correction encoding said transmitted digital signals and including means receiving said modified digital signals, detecting error code bits and data bits therein, correcting said data bits in accordance with said error correction code, and generating corrected data signals; c. an encoder having stored therein said error correction code and including means receiving said corrected data signals, and error correction encoding same; and d. a comparator including means receiving said modified digital signals from said equalizer and said error correction encoded corrected data signals from said encoder, detecting differences therebetween and generating signals indicative of said differences, said difference signals constituting said equalizer control signals.
Claim 3
Dependent Claim
120 words
The system claimed in claim 1 wherein said equalizer comprises: a-1. a first transform circuit having means receiving said transmitted digital signals and generating output signals representative of the frequency spectra thereof; a-2. a second transform circuit having means receiving said comparator produced equalizer control signals and generating output signals representative of the frequency spectra thereof; a-3. means filtering said second transform circuit output signals; a-4. a divider circuit having means receiving said first and said filtered second transform circuit output signals and dividing the former by the latter to generate quotient signals; and a-5. an inverse transform circuit having means receiving said quotient signals and converting same to time domain signals, said last-mentioned signals constituting said modified digital signals.
Claim 4
Independent Claim
245 words
A system for transmission of digital signals from a transmitting station to a receiving station over a communication channel comprising, in combination: at the transmitting station a. a source generating digital data signals; b. an encoder having stored therein a system error correction code and including means receiving said digital data signals and error correction encoding same; c. a modulator including means receiving said error correction encoded digital signals and conditioning same for transmission on said channel; and at the receiving station d. a demodulator including means receiving said transmitted signals from said channel and converting same to digital signals; e. an equalizer circuit including means receiving said digital signals from said demodulator and modifying the characteristics thereof in accordance with receiver-generated equalizer control signals; f. a decoder having stored therein said error correction code and including means receiving said modified digital signals, detecting error code bits and data bits therein, correcting said data bits in accordance with said error correction code, and generating corrected data signals; g. a data utilization device receiving said coRrected data signals; h. an encoder having stored therein said error correction code and including means receiving said corrected data signals and error correction encoding same; and i. a comparator including means receiving said modified digital signals from said equalizer and said error correction encoded corrected data signals from said receiver encoder, detecting differences therebetween and generating signals indicative of said differences, said difference signals constituting said receiver-generated equalizer control signals.
Claim 5
Independent Claim
245 words
A system for transmission of digital signals from a transmitting station to a receiving station over a communication channel comprising, in combination: at the transmitting station a. a source generating digital data signals; b. an encoder having stored therein a system error correction code and including means receiving said digital data signals and error correction encoding same; c. a modulator including means receiving said error correction encoded digital signals and conditioning same for transmission on said channel; and at the receiving station d. a demodulator including means receiving said transmitted signals from said channel and converting same to digital signals; e. an equalizer circuit including means receiving said digital signals from said demodulator and modifying the characteristics thereof in accordance with receiver-generated equalizer control signals; f. a decoder having stored therein said error correction code and including means receiving said modified digital signals, detecting error code bits and data bits therein, correcting said data bits in accordance with said error correction code, and generating corrected data signals; g. a data utilization device receiving said coRrected data signals; h. an encoder having stored therein said error correction code and including means receiving said corrected data signals and error correction encoding same; and i. a comparator including means receiving said modified digital signals from said equalizer and said error correction encoded corrected data signals from said receiver encoder, detecting differences therebetween and generating signals indicative of said differences, said difference signals constituting said receiver-generated equalizer control signals.
Claim 6
Dependent Claim
165 words
A linear time invariant communication channel equalizer for use in an equalization system receiving time varying transmitted signals operated upon by said channel and time varying signals indicative of departures in communication channel phase and amplitude frequency characteristics from ideal responses thereof, comprising, in combination: a. a first transform circuit having means receiving said signals operated upon by said channel and generating output signals representative of the frequency spectra thereof; b. a second transform circuit having means receiving said channel characteristic signals and generating output signals representative of the frequency spectra thereof; c. means filtering said second transform circuit output signals; d. a divider circuit having means receiving said first and said filtered second transform circuit output signals and dividing the former by the latter to generate quotient signals; and e. an inverse transform circuit having means receiving said quotient signals and converting same to time varying output signals, said output signals being representative of said transmitted signals prior to operation thereon by said channel.
Claim 7
Dependent Claim
165 words
A linear time invariant communication channel equalizer for use in an equalization system receiving time varying transmitted signals operated upon by said channel and time varying signals indicative of departures in communication channel phase and amplitude frequency characteristics from ideal responses thereof, comprising, in combination: a. a first transform circuit having means receiving said signals operated upon by said channel and generating output signals representative of the frequency spectra thereof; b. a second transform circuit having means receiving said channel characteristic signals and generating output signals representative of the frequency spectra thereof; c. means filtering said second transform circuit output signals; d. a divider circuit having means receiving said first and said filtered second transform circuit output signals and dividing the former by the latter to generate quotient signals; and e. an inverse transform circuit having means receiving said quotient signals and converting same to time varying output signals, said output signals being representative of said transmitted signals prior to operation thereon by said channel.
References Cited (Backward Citations)
US3457562A
Cited
US3492642A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |