US5123030A
Expired / Lapsed
US
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Timing extraction method and communication system
Assignee: Hitachi Ltd
•
Filing: 1990-03-12
•
Granted: 1992-06-16
•
Expires: 2010-03-12
Abstract
Abstract Clock timing is extracted from N level, multilevel codes of megabits per second data by determining a baud clock among the N-1 possible clocks synchronized to all the level cross points. A discriminator is used with a clock and if correct information is not obtained, the clock is changed.
Inventors
- 👤 Tohru Kazawa
- 👤 Takanori Miyamoto
- 👤 Toshiroh Suzuki
- 👤 Shigeo Nishita
- 👤 Ichiro Masse
- 👤 Takashi Morita
- 👤 Souichi Yamashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:51
CPC Classifications
H; H03; H03M; H03M5/00; H03M5/02; H03M5/20; G; G11; G11B; G11B20/00; G11B20/10; G11B20/10009; G11B20/10037
Claims Analysis
Total Claims: 130
Claim 1
Independent Claim
241 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and wherein said extracting includes generating clock pulses having a frequency (N-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels, dividing the frequency of the clock pulses to generate (N-1) trains of baud clock pulses whose frequencies are equal to the baud, whose pulses are synchronous with some of the cross-timings and whose phases differ from one another according to being synchronous with different ones of the cross timings, discriminating information data with one of the trains of the baud clock pulses and the multilevel code signal to produce a discriminating signal, producing an error signal when error of the information data is detected in the discriminating signal, and in response to the presence of the error signal, continuing said step of discriminating with the next of the trains of baud clock pulses in the succession of (N-1) trains of baud clock pulses and continuing said step of discriminating with the one of the trains of baud clock pulse in the absence of the error signal.
Claim 2
Independent Claim
241 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and wherein said extracting includes generating clock pulses having a frequency (N-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels, dividing the frequency of the clock pulses to generate (N-1) trains of baud clock pulses whose frequencies are equal to the baud, whose pulses are synchronous with some of the cross-timings and whose phases differ from one another according to being synchronous with different ones of the cross timings, discriminating information data with one of the trains of the baud clock pulses and the multilevel code signal to produce a discriminating signal, producing an error signal when error of the information data is detected in the discriminating signal, and in response to the presence of the error signal, continuing said step of discriminating with the next of the trains of baud clock pulses in the succession of (N-1) trains of baud clock pulses and continuing said step of discriminating with the one of the trains of baud clock pulse in the absence of the error signal.
Claim 3
Dependent Claim
35 words
A timing extraction method as defined in claim 1, wherein said setting sets the threshold level at zero so that the crossing signal of all cross timings with the threshold level are zero cross timings.
Claim 4
Dependent Claim
24 words
A timing extraction method as defined in claim 2, said extracting including detecting only the zero cross timings between adjacent correct information discriminative timings.
Claim 5
Dependent Claim
78 words
The timing extraction method according to claim 1, wherein said step of producing an error signal includes, for at least one cross timing, monitoring one information discriminative timing immediately before the one cross timing for a specific level pattern and one discriminative point immediately behind the one cross timing for a different specific level pattern so that the error signal is produced when information data other than the specific level patterns of signs and values has been detected.
Claim 6
Dependent Claim
31 words
A timing extraction method as defined in claim 4, wherein said providing uses a partial response class-4 code, and said monitoring uses patterns that are set at "1, -1" and "-1,1".
Claim 7
Dependent Claim
39 words
A timing extraction method as defined in claim 4, wherein said providing uses a partial response class-4 code, and said monitoring determines whether the specific level patterns are set at "1, 1", "0, 1", "0, -1" and "-1, -1".
Claim 8
Dependent Claim
33 words
A timing extraction method as defined in claim 4, wherein said providing uses a 2B1Q code, and said monitoring specific patterns are set at "3, -3", "1, -1", "-1, 1" and "-3, 3".
Claim 9
Dependent Claim
43 words
A timing extraction method as defined in claim 4, wherein said providing uses a partial response class-4 code, and said monitoring determines an error when any of patterns "1, 1, 1", "1, -1, 1", "-1, 1, -1" and "-1, -1, -1" is detected.
Claim 10
Dependent Claim
43 words
A timing extraction method as defined in claim 1, wherein said producing includes monitoring a frame synchronization pattern of the multilevel code signal, and produces the error signal when a pattern different from the frame synchronization pattern has been detected by said monitoring.
Claim 11
Dependent Claim
28 words
A timing extraction method as defined in claim 9, wherein said monitoring frame synchronization pattern is one in which an identical value does not appear twice in succession.
Claim 12
Dependent Claim
28 words
A timing extraction method as defined in claim 1, wherein said providing uses a partial response class-4 code, and said detecting detects the error as a code-side violation.
Claim 13
Dependent Claim
35 words
A timing extraction method as defined in claim 1, wherein said step of providing provides the multilevel code signal periodically divided into signal frames and said extracting detects a fixed pattern repeated in each frame.
Claim 14
Dependent Claim
37 words
A signal transmission method using the method of claim 1, wherein said providing provides the multilevel code signal in a digitally scrambled form and descrambles the multilevel code signal prior to said steps of forming and extracting.
Claim 15
Dependent Claim
32 words
A communication method employing the method of claim 1, including transmitting the multilevel code signal between an exchanger and terminals by telephone wire with high-speed digital transmission above several megabits per second.
Claim 16
Dependent Claim
29 words
A communication method employing the method of claim 1, in a communication interface device connected between a data terminal and telephone to perform signal transmission and communication protocol processing.
Claim 17
Independent Claim
92 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the band by using the crossing signal and the multilevel code signal; and said extracting including monitoring two discriminative timings directly precedent to one of the crossing signals, and extracting the discriminative timings that have a specified fixed pattern of the two discriminative timings.
Claim 18
Independent Claim
92 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the band by using the crossing signal and the multilevel code signal; and said extracting including monitoring two discriminative timings directly precedent to one of the crossing signals, and extracting the discriminative timings that have a specified fixed pattern of the two discriminative timings.
Claim 19
Independent Claim
87 words
A method of extracting timings from information data comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said extracting including deriving a differentiated waveform of the multilevel code signal, and extracting only timings when the differentiated waveform exceeds a fixed threshold differential level.
Claim 20
Independent Claim
87 words
A method of extracting timings from information data comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said extracting including deriving a differentiated waveform of the multilevel code signal, and extracting only timings when the differentiated waveform exceeds a fixed threshold differential level.
Claim 21
Independent Claim
111 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level: forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and performing the above mentioned steps in a receiving circuit while performing high-speed digital transmission of the multilevel code signal above several megabits per second with telephone wire used as a transmission medium, and providing the circuit with an equalizer, a discriminator, a timing extraction circuit, a decoder and a descrambler.
Claim 22
Independent Claim
111 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level: forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and performing the above mentioned steps in a receiving circuit while performing high-speed digital transmission of the multilevel code signal above several megabits per second with telephone wire used as a transmission medium, and providing the circuit with an equalizer, a discriminator, a timing extraction circuit, a decoder and a descrambler.
Claim 23
Dependent Claim
34 words
A communication method, including the method of claim 18, wherein said providing the circuit includes providing the equalizer, the discriminator, the timing extraction circuit, the decoder and the descrambler on a single semiconductor substrate.
Claim 24
Dependent Claim
47 words
A communication method, including the method according to claim 18, wherein said providing the circuit includes providing a sending circuit including a scrambler, a coder and a sending filter, and a receiving circuit including the equalizer, the discriminator, the timing extraction circuit the decoder and the descrambler.
Claim 25
Dependent Claim
26 words
A transmission method, including the method according to claim 20, wherein said providing provides the receiving circuit and the sending circuit on an identical semiconductor substrate.
Claim 26
Dependent Claim
22 words
The transmission method according to claim 21, including applying an output of the discriminator as an input to the timing extraction circuit.
Claim 27
Dependent Claim
20 words
The method of claim 20, including applying an output of the discriminator as an input to the timing extraction circuit.
Claim 28
Dependent Claim
20 words
The method of claim 18, including applying an output of the discriminator as an input to the timing extraction circuit.
Claim 29
Dependent Claim
32 words
The method of claim 18, wherein said extracting includes deriving a differential waveform of the N-level code signal, and extracting only timings when the differential waveform exceeds a fixed threshold differential level.
Claim 30
Independent Claim
127 words
A method of extracting timings from information date, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; said extracting including delivering clock pulses from a PLL of the baud in synchronism with the cross timings that are coincident with the information discriminative timings by inputting to the PLL only two signals, namely a feedback from the PLL output and a baud portion of the multilevel code signal; and discriminating the information data from the multilevel code signal on the basis of the clock pulses.
Claim 31
Independent Claim
127 words
A method of extracting timings from information date, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; said extracting including delivering clock pulses from a PLL of the baud in synchronism with the cross timings that are coincident with the information discriminative timings by inputting to the PLL only two signals, namely a feedback from the PLL output and a baud portion of the multilevel code signal; and discriminating the information data from the multilevel code signal on the basis of the clock pulses.
Claim 32
Dependent Claim
31 words
The method of claim 26, wherein said setting sets the threshold level at zero so that the crossing signal of all cross timings with the threshold level are zero cross timings.
Claim 33
Dependent Claim
61 words
A timing extraction method as defined in claim 26, wherein said extracting includes numerically adding in a loop filter the phase difference pulses of all of the cross timings and clock pulses of a PLL output, thereafter determining the phase difference pulses that are errors, and numerically subtracting the phase difference pulses that are errors from the result of said adding.
Claim 34
Independent Claim
158 words
A method of extracting timings from information data, comprising: providing an N-level (N being at least equal to 3) code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the N-level code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the code signal; said extracting including delivering, from a PLL, clock pulses having a frequency of N-1 times the baud in synchronism with all the cross timings; dividing the frequency of the clock pulses to produce N-1 trains of baud clock pulses differing in phase from one another; distinguishing one of the N-1 trains of baud clock pulses that is synchronous to the information discriminative timings of the N-level code signal; and discriminating the information data from the N-level code signal on the basis of the on of the N-1 trains of baud clock pulses.
Claim 35
Independent Claim
158 words
A method of extracting timings from information data, comprising: providing an N-level (N being at least equal to 3) code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the N-level code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the code signal; said extracting including delivering, from a PLL, clock pulses having a frequency of N-1 times the baud in synchronism with all the cross timings; dividing the frequency of the clock pulses to produce N-1 trains of baud clock pulses differing in phase from one another; distinguishing one of the N-1 trains of baud clock pulses that is synchronous to the information discriminative timings of the N-level code signal; and discriminating the information data from the N-level code signal on the basis of the on of the N-1 trains of baud clock pulses.
Claim 36
Dependent Claim
31 words
The method of claim 29, wherein said setting sets the threshold level at zero so that the crossing signal of all cross timings with the threshold level are zero cross timings.
Claim 37
Dependent Claim
38 words
The method of claim 30, wherein said extracting includes monitoring two discriminative timings directly precedent to one of the crossing signals, and extracting only the discriminative timings that have a specified fixed pattern of the two discriminative timings.
Claim 38
Dependent Claim
41 words
The method of claim 30, wherein said extracting including detecting only the zero cross timings between adjacent correct information discriminative timings; and wherein said providing uses a partial response class-4 code, and said detecting detects the error as a code-side violation.
Claim 39
Dependent Claim
31 words
The method of claim 30, wherein said step of providing provides the N-level code signal periodically divided into signal frames and said extracting detects a fixed pattern repeated in each frame.
Claim 40
Dependent Claim
32 words
The method of claim 30, wherein said providing provides the N-level code signal in a digitally scrambled form and descrambles the N-level code signal prior to said steps of forming and extracting.
Claim 41
Dependent Claim
28 words
The method of claim 30, including transmitting the N-level code signal between an exchanger and terminals by telephone wire with high-speed digital transmission above several megabits per second.
Claim 42
Dependent Claim
25 words
The method of claim 30, in a communication interface device connected between a data terminal and telephone to perform signal transmission and communication protocol processing.
Claim 43
Dependent Claim
57 words
The method of claim 30, wherein said extracting includes numerically adding in a loop filter the phase difference pulses of all of the cross timings and clock pulses of a PLL output, thereafter determining the phase difference pulses that are errors, and numerically subtracting the phase difference pulses that are errors from the result of said adding.
Claim 44
Dependent Claim
245 words
Apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, comprising: means for setting a threshold level signal; means for forming a crossing signal of all cross timings between the multilevel code signal and the threshold level signal; means extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; said means extracting including means generating clock pulses having a frequency (-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels; means dividing the frequency of the clock pulses to generate (N-1) trains of baud clock pulses whose frequencies are equal to the baud whose pulses are synchronous with some of the cross-timings and whose phases differ from one another according to being synchronous with different ones of the cross timings; means discriminating information data with one of the trains of baud clock pulses and the multilevel code signal to produce a discriminated signal; and means producing an error signal when error of the information data is detected in the discriminating signal, and in response to the presence of the error signal, said means discriminating using the next of the trains of baud clock pulses in the succession of (N-1) trains of baud clock pulses, and said means discriminating continuing discriminating with the one of the trains of baud clock pulse in the absence of the error signal.
Claim 45
Dependent Claim
245 words
Apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, comprising: means for setting a threshold level signal; means for forming a crossing signal of all cross timings between the multilevel code signal and the threshold level signal; means extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; said means extracting including means generating clock pulses having a frequency (-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels; means dividing the frequency of the clock pulses to generate (N-1) trains of baud clock pulses whose frequencies are equal to the baud whose pulses are synchronous with some of the cross-timings and whose phases differ from one another according to being synchronous with different ones of the cross timings; means discriminating information data with one of the trains of baud clock pulses and the multilevel code signal to produce a discriminated signal; and means producing an error signal when error of the information data is detected in the discriminating signal, and in response to the presence of the error signal, said means discriminating using the next of the trains of baud clock pulses in the succession of (N-1) trains of baud clock pulses, and said means discriminating continuing discriminating with the one of the trains of baud clock pulse in the absence of the error signal.
Claim 46
Dependent Claim
32 words
Apparatus of claim 38, wherein said means for setting sets the threshold level at zero so that the crossing signal of all cross timings with the threshold level are zero cross timings.
Claim 47
Dependent Claim
75 words
The apparatus of claim 38, wherein said means producing an error signal includes, for a least one cross timing, means monitoring one information discriminative timing immediately before the one cross timing for a specific level pattern and one discriminative point immediately behind the one cross timing for a different specific level pattern so that the error signal is produced when information data other than the specific level patterns of signs and values has been detected.
Claim 48
Dependent Claim
18 words
Apparatus of claim 40 wherein said means monitoring uses patterns that are set at "1, -1" and "-1,1".
Claim 49
Dependent Claim
26 words
Apparatus of claim 40, wherein said means monitoring determines whether the specific level patterns are set at "1, 1", "0, 1", "0, -1" and "-1, -1".
Claim 50
Dependent Claim
22 words
Apparatus of claim 40, wherein said means monitoring uses specific patterns set at "3, -3", "1, -1", "-1, 1" and "-3, 3".
Claim 51
Dependent Claim
18 words
Apparatus of claim 40, wherein said means monitoring uses a frame synchronization pattern of the multilevel code signal.
Claim 52
Dependent Claim
22 words
Apparatus of claim 44, wherein said frame synchronization pattern is one in which an identical value does not appear twice in succession.
Claim 53
Dependent Claim
29 words
Apparatus of claim 38, including means providing the multilevel code signal in a digitally scrambled form and means that descrambles the multilevel code signal prior to said means extracting.
Claim 54
Dependent Claim
50 words
A communication system employing the apparatus of claim 38, including an exchanger; a plurality of terminals; telephone wires connecting said exchanger with said terminals; and means transmitting the multilevel code signal between said exchanger and said terminals by said telephone wires with high-speed digital transmission above several megabits per second.
Claim 55
Dependent Claim
94 words
Apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, comprising: means for setting a threshold level signal: means for forming a crossing signal of all cross timings between the multilevel code signal and the threshold level signal; and means extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said means extracting including means for deriving a differentiated waveform of the multilevel code signal and extracting only timings when the differentiated waveform exceeds a fixed threshold differential level.
Claim 56
Dependent Claim
94 words
Apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, comprising: means for setting a threshold level signal: means for forming a crossing signal of all cross timings between the multilevel code signal and the threshold level signal; and means extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said means extracting including means for deriving a differentiated waveform of the multilevel code signal and extracting only timings when the differentiated waveform exceeds a fixed threshold differential level.
Claim 57
Dependent Claim
111 words
A communication circuit, comprising: a timing extraction circuit including apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, said apparatus comprising, means for setting a threshold level signal, means for forming a crossing signal of all cross timings between the multilevel code signal and the threshold level signal, and means extracting information discriminate timings of the baud by using the crossing signal and the multilevel code signal; and telephone wire, an equalizer, a discriminator, a decoder, a descrambler, and means performing high-speed digital transmission of the multilevel code signal above several megabits per second with said telephone wire used as a transmission medium.
Claim 58
Dependent Claim
111 words
A communication circuit, comprising: a timing extraction circuit including apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, said apparatus comprising, means for setting a threshold level signal, means for forming a crossing signal of all cross timings between the multilevel code signal and the threshold level signal, and means extracting information discriminate timings of the baud by using the crossing signal and the multilevel code signal; and telephone wire, an equalizer, a discriminator, a decoder, a descrambler, and means performing high-speed digital transmission of the multilevel code signal above several megabits per second with said telephone wire used as a transmission medium.
Claim 59
Dependent Claim
38 words
A communication circuit according to claim 49, including a sending circuit including a scrambler, a coder and a sending filter, and a receiving circuit including the equalizer, the discriminator, the timing extraction circuit, the decoder and the descrambler.
Claim 60
Dependent Claim
20 words
A communication circuit according to claim 50, wherein said receiving circuit and sending circuit are on an identical semiconductor substrate.
Claim 61
Dependent Claim
23 words
A communication circuit according to claim 51, including means connecting an output of the discriminator as an input to the timing extraction circuit.
Claim 62
Dependent Claim
23 words
A communication circuit according to claim 50, including means connecting an output of the discriminator as an input to the timing extraction circuit.
Claim 63
Dependent Claim
23 words
A communication circuit according to claim 49, including means connecting an output of the discriminator as an input to the timing extraction circuit.
Claim 64
Dependent Claim
35 words
The communication circuit of claim 49, wherein said means extracting includes deriving a differentiated waveform of the N-level code signal, and means extracting only timings when the differentiated waveform exceeds a fixed threshold differential level.
Claim 65
Dependent Claim
22 words
A communication circuit of claim 49, wherein said equalizer, discriminator, timing extraction circuit, decoder and descrambler are on a single semiconductor substrate.
Claim 66
Dependent Claim
155 words
Apparatus for extracting timings from an N-level (N being at least equal to 3) code signal having information discriminative timings and having a baud, comprising: means for forming a crossing signal of all cross timings between the N-level code signal and a threshold level; means extracting information discriminative timings of the baud by using the crossing signal and the N-level code signal; said means extracting including a PLL delivering clock pulses having a frequency of N-1 times the baud in synchronism with all the cross timings; means dividing the frequency of the clock pulses to produce N-1 trains of baud clock pulses differing in phase from one another; means distinguishing one of the trains of baud clock pulses that is synchronous to the information discriminative timings of the N-level code signal; and means discriminating the information data from the N-level code signal on the basis of the one of the trains of baud clock pulses.
Claim 67
Dependent Claim
155 words
Apparatus for extracting timings from an N-level (N being at least equal to 3) code signal having information discriminative timings and having a baud, comprising: means for forming a crossing signal of all cross timings between the N-level code signal and a threshold level; means extracting information discriminative timings of the baud by using the crossing signal and the N-level code signal; said means extracting including a PLL delivering clock pulses having a frequency of N-1 times the baud in synchronism with all the cross timings; means dividing the frequency of the clock pulses to produce N-1 trains of baud clock pulses differing in phase from one another; means distinguishing one of the trains of baud clock pulses that is synchronous to the information discriminative timings of the N-level code signal; and means discriminating the information data from the N-level code signal on the basis of the one of the trains of baud clock pulses.
Claim 68
Dependent Claim
29 words
The apparatus of claim 57, wherein the threshold level is at zero so that the crossing signal of all cross timings with the threshold level are zero cross timings.
Claim 69
Dependent Claim
29 words
The apparatus of claim 58, including means providing the N-level code signal periodically divided into signal frames and said means extracting detects a fixed pattern repeated in each frame.
Claim 70
Dependent Claim
25 words
The apparatus of claim 58, including means providing the N-level code signal in a digitally scrambled form and means that descrambles the N-level code signal.
Claim 71
Dependent Claim
38 words
The apparatus of claim 58 including an exchanger, a plurality of terminals, and means transmitting the N-level code signal between said exchanger and said terminals by said telephone wire with high-speed digital transmission above several megabits per second.
Claim 72
Dependent Claim
36 words
A communication system comprising a communication interface of claim 58, a data terminal, a telephone, and means connecting said communication interface between said data terminal and said telephone to perform signal transmission and communication protocol processing.
Claim 73
Dependent Claim
70 words
The apparatus of claim 58, wherein said means extracting includes a PLL receiving the N-level code signal and having an output, a loop filter means numerically adding the phase difference pulses of all of the cross timings and clock pulses of said PLL output, means determining the phase difference pulses that are errors, and means numerically subtracting the phase difference pulses that are errors from the result of said adding.
Claim 74
Dependent Claim
38 words
The apparatus of claim 58, wherein said means extracting monitors two discriminative timings directly precedent to one of the crossing signals, and extracts only the discriminative timings that have a specified fixed pattern of the two discriminative timings.
Claim 75
Dependent Claim
93 words
Apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, comprising: means for forming a crossing signal of all cross timings between the multilevel code signal and a predetermined threshold level; means extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said means extracting including a PLL receiving only two signal inputs, namely a feedback of the PLL output and the crossing signal which is coincident with discriminative timings of a baud portion of the crossing signal.
Claim 76
Dependent Claim
93 words
Apparatus for extracting timings from a multilevel code signal having information discriminative timings and having a baud, comprising: means for forming a crossing signal of all cross timings between the multilevel code signal and a predetermined threshold level; means extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said means extracting including a PLL receiving only two signal inputs, namely a feedback of the PLL output and the crossing signal which is coincident with discriminative timings of a baud portion of the crossing signal.
Claim 77
Dependent Claim
25 words
The apparatus of claim 65, including means discriminating information data out of said multilevel code signal according to said information discriminative timings of the baud-rate.
Claim 78
Dependent Claim
189 words
The apparatus of claim 66, wherein said means extracting includes means generating clock pulses having a frequency (N-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels; means dividing the frequency of the clock pulses to generate (N-1) trains of baud clock pulses whose frequencies are equal to the baud, whose pulses are synchronous with only some of the cross-timings and whose phases differ from one another according to being synchronous with different ones of the cross timings; means discriminating information data with only one of the trains of baud clock pulses and the multilevel code signal to produce a discriminated signal; means producing an error signal when error of the information data is detected in the discriminated signal; and in response to the presence of the error signal, said means discriminating using the next of the trains of baud clock pulses in the succession of (N-1) trains of baud clock pulses, and said means discriminating continuing discriminating with the one of the trains of baud clock pulse in the absence of the error signal.
Claim 79
Dependent Claim
75 words
The apparatus of claim 67, wherein said means producing an error signal includes, for at least one cross timing, means monitoring one information discriminative timing immediately before the one cross timing for a specific level pattern and one discriminative point immediately behind the one cross timing for a different specific level pattern so that the error signal is produced when information data other than the specific level patterns of signs and values has been detected.
Claim 80
Dependent Claim
39 words
A communication system having a communication interface, a data terminal and a telephone, employing the apparatus of claim 65 in said communication interface connected between said data terminal and said telephone to perform signal transmission and communication protocol processing.
Claim 81
Dependent Claim
189 words
The apparatus of claim 65, wherein said means extracting includes means generating clock pulses having a frequency (N-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels; means dividing the frequency of the clock pulses to generate (N-1) trains of baud clock pulses whose frequencies are equal to the baud, whose pulses are synchronous with only some of the cross-timings and whose phases differ from one another according to being synchronous with different ones of the cross timings; means discriminating information data with only one of the trains of baud clock pulses and the multilevel code signal to produce a discriminated signal; means producing an error signal when error of the information data is detected in the discriminated signal; and in response to the presence of the error signal, said means discriminating using the next of the trains of baud clock pulses in the succession of (N-1) trains of baud clock pulses, and said means discriminating continuing discriminating with the one of the trains of baud clock pulse in the absence of the error signal.
Claim 82
Dependent Claim
75 words
The apparatus of claim 70, wherein said means producing an error signal includes, for at least one cross timing, means monitoring one information discriminative timing immediately before the one cross timing for a specific level pattern and one discriminative point immediately behind the one cross timing for a different specific level pattern so that the error signal is produced when information data other than the specific level patterns of signs and values has been detected.
Claim 83
Dependent Claim
29 words
The apparatus of claim 71, including means providing the multilevel code signal periodically divided into signal frames and said means extracting detects a fixed pattern repeated in each frame.
Claim 84
Dependent Claim
30 words
The apparatus of claim 65, wherein the threshold level is equal to zero so that the crossing signal of all cross timings with the threshold level are zero cross timings.
Claim 85
Dependent Claim
38 words
The apparatus of claim 65, wherein said means extracting monitors two discriminative timings directly proceeding to one of the crossing signals and extracts only that discriminative timings that have a specified fixed pattern of the two discriminative timings.
Claim 86
Dependent Claim
35 words
The apparatus of claim 65, wherein said means extracting includes means deriving a differentiated waveform of the multilevel code signal, and means extracting only timings when the differentiated waveform exceeds at fixed threshold differential level.
Claim 87
Dependent Claim
58 words
The apparatus of claim 65, wherein said means extracting includes a loop filter means numerically adding the phase difference pulses of all the cross timings and clock pulses of the PLL output, means determining the phase different pulses that are errors, and means numerically subtracting the phase difference pulse that are errors from the result of said adding.
Claim 88
Dependent Claim
44 words
The apparatus of claim 65, including means distinguishing a first portion of the crossing signal having the timing of the information discriminative timings from the remaining portion of the crossing signal, and outputting the first portion as one of the inputs of the PLL.
Claim 89
Dependent Claim
21 words
The apparatus of claim 77, wherein said means distinguishing receives as inputs only the crossing signal and the information discriminative timings.
Claim 90
Dependent Claim
28 words
The apparatus of claim 78, further including pattern select means modifying the information discriminative timings in accordance with the baud clock signal and outputting to the means distinguishing.
Claim 91
Dependent Claim
14 words
The apparatus of claim 79, wherein said means distinguishing is a two-input AND circuit.
Claim 92
Dependent Claim
21 words
The apparatus of claim 77, wherein said means distinguishing receives inputs of only the crossing signal and the N-level code signal.
Claim 93
Dependent Claim
19 words
The apparatus of claim 81, wherein said means distinguishing differentiates the N-level code signal to produce a differentiated signal.
Claim 94
Dependent Claim
38 words
The apparatus of claim 82, wherein said means distinguishing combines only that portion of the differentiated signal that exceeds a threshold level with the crossing signal to produce an output fed directly as an input to the PLL.
Claim 95
Dependent Claim
42 words
The apparatus of claim 81, wherein said means distinguishing full wave rectifies the N-level code signal to produce a rectified signal, and combines the rectified signal with the crossing signal to produce an output fed directly as an input to the PLL.
Claim 96
Dependent Claim
133 words
Apparatus for extracting timings from an N-level code signal having information discriminative timings and having a baud, comprising: means for forming a crossing signal of all cross timings between the N-level code signal and a predetermined threshold level; a PLL delivering clock pulses having a frequency of N-1 times baud and including clock pulses in synchronism with at least the cross timings that are coincident with the information discriminative timings; means for dividing the clock pulses into N-1 trains of the clock pulses; means for extracting the information data from the N-level code signal on the basis of one of the N-1 trains of the clock pulses to output an information data signal; and said PLL having two signal inputs, namely a feedback of the clock pulses and all of the cross timings.
Claim 97
Dependent Claim
133 words
Apparatus for extracting timings from an N-level code signal having information discriminative timings and having a baud, comprising: means for forming a crossing signal of all cross timings between the N-level code signal and a predetermined threshold level; a PLL delivering clock pulses having a frequency of N-1 times baud and including clock pulses in synchronism with at least the cross timings that are coincident with the information discriminative timings; means for dividing the clock pulses into N-1 trains of the clock pulses; means for extracting the information data from the N-level code signal on the basis of one of the N-1 trains of the clock pulses to output an information data signal; and said PLL having two signal inputs, namely a feedback of the clock pulses and all of the cross timings.
Claim 98
Dependent Claim
29 words
Apparatus of claim 85, including means providing the N-level code signal periodically divided into signal frames and said means for extracting detects a fixed pattern repeated in each frame.
Claim 99
Dependent Claim
33 words
The apparatus of claim 85, wherein said means for setting sets the threshold level at zero so that the crossing signal of all cross timings with the threshold level are zero cross timings.
Claim 100
Dependent Claim
37 words
The apparatus of claim 85, wherein said means for extracting extracts the information of discriminative timings of the baud by using the crossing signal and the information data obtained by said means for extracting the information data.
Claim 101
Dependent Claim
31 words
The apparatus of claim 85, including means for providing the N-level code signal in a digitally scrambled form and means that descrambles the N-level code signal prior to said means extracting.
Claim 102
Dependent Claim
27 words
The apparatus of claim 85, further including means for distinguishing a baud clock signal with correct timings from the (N-1) baud clock signal output from said PLL.
Claim 103
Dependent Claim
28 words
The apparatus of claim 90, wherein said means for extracting directly receives the baud clock signal from the means for distinguishing to combine with the N-level code signal.
Claim 104
Dependent Claim
34 words
The apparatus of claim 90, wherein said means for extracting further includes a latch receiving the baud clock signal from the means for distinguishing as an enable signal to output the information discriminative timings.
Claim 105
Dependent Claim
22 words
The apparatus of claim 90, wherein said means for distinguishing has an input to receive a signal from said means for extracting.
Claim 106
Dependent Claim
20 words
The apparatus of claim 90, wherein said means for distinguishing receives the information discriminative timings from said means for extracting.
Claim 107
Dependent Claim
34 words
The apparatus of claim 90, wherein said means for distinguishing receives the N-level code signal and the (N-1) baud clock signal, and said means extracting includes latch means enabled by the baud clock signal.
Claim 108
Independent Claim
102 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said extracting including generating clock pulses having a frequency (N-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels where N is an integer greater than two.
Claim 109
Independent Claim
102 words
A method of extracting timings from information data, comprising: providing a multilevel code signal having information discriminative timings and having a baud; setting a threshold level; forming a crossing signal of all cross timings between the multilevel code signal and the threshold level; extracting information discriminative timings of the baud by using the crossing signal and the multilevel code signal; and said extracting including generating clock pulses having a frequency (N-1) times the baud and synchronously to the (N-1) different cross timings of the crossing signal, where the multilevel code signal has N levels where N is an integer greater than two.
Claim 110
Dependent Claim
27 words
The method according to claim 96, wherein said extracting includes discriminating information data with the clock pulses and the multilevel code signal to produce a discriminated signal.
Claim 111
Dependent Claim
28 words
The method according to claim 96, wherein said extracting includes distinguishing a baud clock synchronous with only the cross timings that are synchronous with the information discriminative timings.
Claim 112
Dependent Claim
27 words
The method according to claim 98, wherein said extracting includes discriminating information data with the clock pulses and the multilevel code signal to produce a discriminated signal.
Claim 113
Dependent Claim
23 words
The method according to claim 99, wherein said extracting extracts the information discriminative timings by combining the baud clock and the discriminated signal.
Claim 114
Dependent Claim
58 words
The method of claim 98, said distinguishing including dividing the frequency of the clock pulses to generate (N-1) trains of baud clock pulses whose frequencies are equal to the baud, whose pulses are synchronous with only some of the cross-timings and whose phases differ from one another according to being synchronous with different ones of the cross timings.
Claim 115
Dependent Claim
50 words
The method of claim 101, wherein said distinguishing further includes passing the (N-1) times the baud clock pulses through a frame synchronizer together with the discriminated signal to produce a synchronized signal and separating the baud clock from the trains of baud clock pulses in accordance with the synchronized signal.
Claim 116
Dependent Claim
25 words
The method of claim 101, wherein said extracting enables a latch by the baud clock to separate the information discriminative timings from the discriminated signal.
Claim 117
Dependent Claim
126 words
Apparatus for extracting information data from a multilevel code signal encoded by a partial response class 4 code at a predetermined baud, comprising: means for forming a crossing signal of cross timings between the multilevel code signal and a predetermined threshold level; a PLL delivering clock pulses having a frequency two times the baud in synchronism with the crossing signal, said PLL receiving signal inputs of a feedback of the PLL output clock pulses having a frequency two times the baud and the crossing signal; and extracting means for extracting the information data on a basis of one of two trains of baud clock pulses obtained by using the clock pulses having a frequency two times the baud from the PLL and the multilevel code signal.
Claim 118
Dependent Claim
126 words
Apparatus for extracting information data from a multilevel code signal encoded by a partial response class 4 code at a predetermined baud, comprising: means for forming a crossing signal of cross timings between the multilevel code signal and a predetermined threshold level; a PLL delivering clock pulses having a frequency two times the baud in synchronism with the crossing signal, said PLL receiving signal inputs of a feedback of the PLL output clock pulses having a frequency two times the baud and the crossing signal; and extracting means for extracting the information data on a basis of one of two trains of baud clock pulses obtained by using the clock pulses having a frequency two times the baud from the PLL and the multilevel code signal.
Claim 119
Dependent Claim
236 words
Apparatus for extracting information data from a multilevel code signal encoded by a partial response class 4 code at a predetermined baud, comprising: means for forming a crossing signal of cross timings between the multilevel code signal and a predetermined threshold level; a PLL delivering clock pulses having a frequency two times the baud in synchronism with the crossing signal, said PLL receiving signal inputs of a feedback of the PLL output and the crossing signal; and extracting means for extracting the information data on a basis of information discriminative timings obtained by using the clock pulses from the PLL and the multilevel code signal, wherein said extracting means includes means for generating two baud clock pulse trains from the clock pulses so that the trains are synchronous with different ones of some of the cross timings and so that the trains phase differ from one another according to being synchronous with the different cross timings, means for distinguishing one of the trains that is synchronous to the information discriminative timings of the multilevel code signal from the other of the trains that is not synchronous to the information discriminative timings of the multilevel code signal, means for discriminating the information data from the multilevel code signal by using the one of the trains as the information discriminative timings, and wherein said means for distinguishing distinguishes the one of the trains by using the information data.
Claim 120
Dependent Claim
236 words
Apparatus for extracting information data from a multilevel code signal encoded by a partial response class 4 code at a predetermined baud, comprising: means for forming a crossing signal of cross timings between the multilevel code signal and a predetermined threshold level; a PLL delivering clock pulses having a frequency two times the baud in synchronism with the crossing signal, said PLL receiving signal inputs of a feedback of the PLL output and the crossing signal; and extracting means for extracting the information data on a basis of information discriminative timings obtained by using the clock pulses from the PLL and the multilevel code signal, wherein said extracting means includes means for generating two baud clock pulse trains from the clock pulses so that the trains are synchronous with different ones of some of the cross timings and so that the trains phase differ from one another according to being synchronous with the different cross timings, means for distinguishing one of the trains that is synchronous to the information discriminative timings of the multilevel code signal from the other of the trains that is not synchronous to the information discriminative timings of the multilevel code signal, means for discriminating the information data from the multilevel code signal by using the one of the trains as the information discriminative timings, and wherein said means for distinguishing distinguishes the one of the trains by using the information data.
Claim 121
Dependent Claim
116 words
The apparatus of claim 104, wherein said extracting means includes: means for receiving the multilevel code signal and the clock pulses having a frequency two times baud from the PLL as inputs, and for outputting an output signal which is obtained by discriminating the multilevel code signal at timings of the clock pulses, said output signal including the information data; means for distinguishing discriminative timings in synchronism with one of said two trains of the baud clock pulses obtained from the clock pulses by using the output signal of said means for receiving; and means for discriminating the information data from the output signal of said means for receiving on the basis of the discriminative timings.
Claim 122
Dependent Claim
52 words
A communication system employing the apparatus of claim 104, including: an exchanger; a plurality of terminals; telephone wires connecting said exchanger with said terminals; and means transmitting the multilevel code signal between said exchanger and said terminals by said telephone wires with high speed digital transmission substantially above four megabits per second.
Claim 123
Independent Claim
137 words
An apparatus for discriminating information data from multilevel code signal encoded by a partial response class-4 code at a predetermined baud, comprising: means for forming a crossing signal of all cross timings between the multilevel code signal and a predetermined threshold level; means for selecting, from the crossing signal, some cross timings synchronous to information discriminative timings of the multilevel code signal; a PLL delivering an output of baud clock pulses synchronous to the information discriminative timings by using only signal inputs of a feedback of the PLL output and the some cross timings selected by said selecting means; means for discriminating the information data from the multilevel code signal on the basis of the baud clock pulses; and wherein said means selecting selects the some cross timings from the crossing signal by using the information data.
Claim 124
Independent Claim
137 words
An apparatus for discriminating information data from multilevel code signal encoded by a partial response class-4 code at a predetermined baud, comprising: means for forming a crossing signal of all cross timings between the multilevel code signal and a predetermined threshold level; means for selecting, from the crossing signal, some cross timings synchronous to information discriminative timings of the multilevel code signal; a PLL delivering an output of baud clock pulses synchronous to the information discriminative timings by using only signal inputs of a feedback of the PLL output and the some cross timings selected by said selecting means; means for discriminating the information data from the multilevel code signal on the basis of the baud clock pulses; and wherein said means selecting selects the some cross timings from the crossing signal by using the information data.
Claim 125
Dependent Claim
51 words
A communication system employing the apparatus of claim 108, including: an exchanger; a plurality of terminals; telephone wires connecting said exchanger with said terminals; and means transmitting the multilevel code signal between said exchanger and said terminals by said telephone wires with high-speed digital transmission substantially above four megabits per second.
Claim 126
Independent Claim
139 words
An apparatus for discriminating information data from multilevel code signal encoded by a partial response class-4 code at a predetermined baud, comprising: means for forming a crossing signal of all cross timings between the multilevel code signal and a predetermined threshold level; means for selecting, from the crossing signal, some cross timings synchronous to information discriminative timings of the multilevel code signal; and a PLL delivering an output of baud clock pulses synchronous to the information discriminative timings by using only signal inputs of a feedback of the PLL output and the some crossing timings selected by said selecting means; means for discriminating the information data from the multilevel code signal on basis of the baud clock pulses; and wherein said means for selecting selects the some cross timings from the crossing signal by using the multilevel code signal.
Claim 127
Independent Claim
139 words
An apparatus for discriminating information data from multilevel code signal encoded by a partial response class-4 code at a predetermined baud, comprising: means for forming a crossing signal of all cross timings between the multilevel code signal and a predetermined threshold level; means for selecting, from the crossing signal, some cross timings synchronous to information discriminative timings of the multilevel code signal; and a PLL delivering an output of baud clock pulses synchronous to the information discriminative timings by using only signal inputs of a feedback of the PLL output and the some crossing timings selected by said selecting means; means for discriminating the information data from the multilevel code signal on basis of the baud clock pulses; and wherein said means for selecting selects the some cross timings from the crossing signal by using the multilevel code signal.
Claim 128
Dependent Claim
46 words
The apparatus of claim 110, wherein: said means for selecting includes means for deriving a differentiated waveform of the multilevel code signal; and said means for selecting selects the some cross timings from the crossing signal when the differentiated waveform exceeds a fixed threshold differential level.
Claim 129
Dependent Claim
39 words
The apparatus of claim 110, wherein: said means for selecting includes means for fullwave rectifying the multilevel code signal to produce a rectified signal and selects the some cross timings from the crossing signal by using the rectified signal.
Claim 130
Dependent Claim
51 words
A communication system employing the apparatus of claim 110, including: an exchanger; a plurality of terminals; telephone wires connecting said exchanger with said terminals; and means transmitting the multilevel code signal between said exchanger and said terminals by said telephone wires with high-speed digital transmission substantially above four megabits per second.
References Cited (Backward Citations)
US3978284A
Cited
US4351061A
Cited
US4367495A
Cited
US4386323A
Cited
US4355408A
Cited
US4584690A
Cited
US4775989A
Cited
US4775984A
Cited
US4924492A
Cited
USPTO Annuity & Maintenance Windows
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