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公开(公告)号：DE3784490T2
公开(公告)日：1993-09-16
申请号：DE3784490
申请日：1987-04-22
Applicant: IBM
Inventor： BELLOC JACQUES , MORLEC EMILE , GODARD DOMINIQUE , QUINTIN MICHEL
Abstract: Echo cancelling device for providing an echo-free incoming data signal with a phase-roll tracking device comprising phase rotating means (58) for rotating the phase of the generated echo signal by a value X which is the estimated phase-roll value, thereby providing a complex phase-roll corrected echo signal a multiplier (124) for multiplying the error signal between the incoming signal and the real component (112) of the phase-roll corrected echo signal by the imaginary component (120) of the same signal, thereby providing a value Y function of the variation of the phase-roll; a phase-roll variation estimator (128) providing an estimation Z of the phase-roll variation X in half duplex mode or in full duplex mode, in response to value Y; and a phase filter (126) providing the estimated phase-roll value X in response to the estimation Z.
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公开(公告)号：DE68915274D1
公开(公告)日：1994-06-16
申请号：DE68915274
申请日：1989-07-12
Applicant: IBM
Inventor： CHEVILLAT PIERRE RENE , ELEFTHERIOU EVANGELOS , MAIWALD DIETRICH G U , QUINTIN MICHEL
Abstract: In a data transmission wherein a transmitting modem transmits data signals to a receiving modem via a telephone line, the process of the invention consists in rotating (12), in the transmitting modem, the phase of the point of the constellation resulting from a group of data bits by a predetermined phase value, and then rotating (22) after, a predetermined delay in the receiving modem, the phase of the estimated point resulting from the transformation of the analog signal, by the opposite of said predetermined phase value, the mean-square error between the rotated point and the estimated point of the constellation being used to determine whether the receiving modem is out of synchronization or not.
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公开(公告)号：DE3888830D1
公开(公告)日：1994-05-05
申请号：DE3888830
申请日：1988-08-30
Applicant: IBM
Inventor： BELLOC JACQUES , GALAND CLAUDE , LANCON EMMANUEL , MILEWSKI ANDRE , QUINTIN MICHEL
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公开(公告)号：DE68908149T2
公开(公告)日：1994-03-17
申请号：DE68908149
申请日：1989-01-10
Applicant: IBM
Inventor： BELLOC JACQUES , PILOST DANIEL , QUINTIN MICHEL
Abstract: Modem receiving from/transmitting to a DTE data bits at a rate DR and adapted for operating at a modulation rate MR in an environment operating at a basic rate BR. In the receiving way, it comprises a first means for converting a number X of samples received at a frequency FS into a number X.MR/BR of samples before processing these samples by the signal processor whereby the processing results in DR/BR words of DR/MR bits, and second means for converting the DR/BR words into DR/MR words of DR/BR bits to be transmitted to the DTE. For the transmitting way the first and second converting means, are the same means but run in the reverse order. The result is that such an adapted modem behaves as a modem operating at a modulation rate MR on a periodic process interval of DR/(BR.MR) s.
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公开(公告)号：DE68908149D1
公开(公告)日：1993-09-09
申请号：DE68908149
申请日：1989-01-10
Applicant: IBM
Inventor： BELLOC JACQUES , PILOST DANIEL , QUINTIN MICHEL
Abstract: Modem receiving from/transmitting to a DTE data bits at a rate DR and adapted for operating at a modulation rate MR in an environment operating at a basic rate BR. In the receiving way, it comprises a first means for converting a number X of samples received at a frequency FS into a number X.MR/BR of samples before processing these samples by the signal processor whereby the processing results in DR/BR words of DR/MR bits, and second means for converting the DR/BR words into DR/MR words of DR/BR bits to be transmitted to the DTE. For the transmitting way the first and second converting means, are the same means but run in the reverse order. The result is that such an adapted modem behaves as a modem operating at a modulation rate MR on a periodic process interval of DR/(BR.MR) s.
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Patent Agency Ranking
公开(公告)号：DE3783605D1
公开(公告)日：1993-02-25
申请号：DE3783605
申请日：1987-04-22
Applicant: IBM
Inventor： BELLOC JACQUES , MORLEC EMILE , GODARD DOMINIQUE , QUINTIN MICHEL
Abstract: Near (20) and far (22) echo cancellers have outputs summed by an adder (26) to provide an estimated echo signal in digital form from the transmitted outgoing digital signal. A first path includes a DAC (48) for converting the digital estimated echo to analog form and an analog subtractor (52) receiving the analog estimated echo and the incoming signal to provide an echo-free analog incoming signal. A second path includes an ADC (42) converting the analog incoming signal to digital form, and a digital subtractor (44) receives the digital estimated echo and the digital incoming signal to provide a digital signal used as a source for control of the echo cancellers.
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公开(公告)号：DE3888830T2
公开(公告)日：1994-11-24
申请号：DE3888830
申请日：1988-08-30
Applicant: IBM
Inventor： BELLOC JACQUES , GALAND CLAUDE , LANCON EMMANUEL , MILEWSKI ANDRE , QUINTIN MICHEL
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公开(公告)号：DE68915274T2
公开(公告)日：1994-11-10
申请号：DE68915274
申请日：1989-07-12
Applicant: IBM
Inventor： CHEVILLAT PIERRE RENE , ELEFTHERIOU EVANGELOS , MAIWALD DIETRICH G U , QUINTIN MICHEL
Abstract: In a data transmission wherein a transmitting modem transmits data signals to a receiving modem via a telephone line, the process of the invention consists in rotating (12), in the transmitting modem, the phase of the point of the constellation resulting from a group of data bits by a predetermined phase value, and then rotating (22) after, a predetermined delay in the receiving modem, the phase of the estimated point resulting from the transformation of the analog signal, by the opposite of said predetermined phase value, the mean-square error between the rotated point and the estimated point of the constellation being used to determine whether the receiving modem is out of synchronization or not.
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公开(公告)号：DE3783605T2
公开(公告)日：1993-07-15
申请号：DE3783605
申请日：1987-04-22
Applicant: IBM
Inventor： BELLOC JACQUES , MORLEC EMILE , GODARD DOMINIQUE , QUINTIN MICHEL
Abstract: Echo cancelling device for cancelling echoes affecting the incoming signal received over a two-wire telephone line, comprising near echo canceller 20, far echo canceller 22 and an adder 26 providing the estimated echo signal. A circuit path including a digital-to-analog converter 48 for converting the digital estimated echo signal into analog form and a subracter 52 for subtracting the resulting analog signal from the analog incoming signal, is separated from a circuit path including an analog-to-digital converter 42 for converting the analog incoming signal into digital form and a subtracter 44 for subtracting the digital estimated echo signal from the resulting digital incoming signal thereby providing a digital signal used as a control signal for adjusting the echo cancellers 20 and 22.
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公开(公告)号：DE3784490D1
公开(公告)日：1993-04-08
申请号：DE3784490
申请日：1987-04-22
Applicant: IBM
Inventor： BELLOC JACQUES , MORLEC EMILE , GODARD DOMINIQUE , QUINTIN MICHEL
Abstract: A multiplier (58) phase rotates a generated echo signal by a value X which is the estimated phase-roll value to provide a complex phase-roll connected signal. The error signal differenced between the incoming signal and the real component (112) of the corrected signal is then multipled (124) by the imaginary component (120) to provide a value Y. A phase variation estimator (128) determines the phase roll value Z in half-duplex mode, as well as in full-duplex mode, in response to this value Y. A phase filter (126) provides the estimated value X in response to the phase-roll value Z. Pref. the estimator (128) includes a third multiplier providing a value proportional to the value Y and a fourth multiplier multiplying the sign bits to provide a low-value estimate of the value Z.
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