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公开(公告)号：DE3374109D1
公开(公告)日：1987-11-19
申请号：DE3374109
申请日：1983-10-28
Applicant: IBM , IBM FRANCE
Inventor： CALLENS PAUL , GALAND CLAUDE , PLATEL GUY , VERMOT-GAUCHY ROBERT
Abstract: Input to a controller (42) is demodulated by a double-sideband quadrature-carrier modem supplying bits to a microprocessor (70) with a buffer memory (50) for a given number of packets. A validation device (52) checks the content and number of each packet for arrival in the correct sequence. The contents of each valid packet are distributed among the decoders via demultiplexers (11) sepg. signal data from HF band energy and partial autocorrelation coefft. data. The signal in each subband of coded sequences on either side of a missing sequence is analysed and used to conserve periodicity while avoiding abrupt transitions between received and reconstituted signals.
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公开(公告)号：DE3270212D1
公开(公告)日：1986-05-07
申请号：DE3270212
申请日：1982-04-30
Applicant: IBM , IBM FRANCE
Inventor： CALLENS PAUL , GALAND CLAUDE
Abstract: This coder dispatches the bits resulting from the coding operation of a speech signal into a format for transmission at a rate chosen from a plurality of predetermined transmission rates. More specifically, the contents of at least part of the speech signal frequency bandwidth is split into several sub-bands. Said sub-bands are regrouped into sub-groups, each of said sub-groups corresponding to at least one of said possible transmission rates, i.e. to at least one sub-group coding bit rate. The signal samples belonging to each sub-group are recoded through a dynamical allocation of requantizing steps between the sub-bands. The obtained bits resulting from the recoding are dispatched into a multirate frame according to the sub-group which they belong to.
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Patent Agency Ranking
公开(公告)号：DE3479468D1
公开(公告)日：1989-09-21
申请号：DE3479468
申请日：1984-05-23
Applicant: IBM , IBM FRANCE
Inventor： CALLENS PAUL , NOAILLY PHILIPPE , GALAND CLAUDE , SECONDO PIERRE , GERGAUD CLAUDE
Abstract: A method of transmitting digitized voice signals as packets of bits in a digital transmission network to which a plurality of terminals acting as sources of voice signals are attached. The method includes, at the transmitting end and for each source, the steps of: a dividing the signal into successive, digitally-coded segments; performing a so-called source activity detection; and assembling the bits resulting from the coding operation into packets, each packet being provided with a header containing, in particular, a parity bit whose logic value is modified whenever an inactivity or long pause is detected. At the receiving end, detection of a change in the value of said parity bit causes the delivery of a packet of bits to the decoder/synthesizer to be delayed by a given time interval called retention delay.
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公开(公告)号：CA1245780A
公开(公告)日：1988-11-29
申请号：CA462994
申请日：1984-09-12
Applicant: IBM
Inventor： CALLENS PAUL , GALAND CLAUDE , PLATEL GUY , VERMOT-GAUCHY ROBERT
Abstract: A method of reconstructing, at the receiving end, digital data defining an encoded voice signal segment lost in transmission between the transmitter and the receiver in a transmission system wherein a low-frequency signal such as a residual baseband signal is derived at the transmitting end from the signal to be encoded and is then distributed among several sub-bands whose sampled contents are quantized separately. The reconstruction method includes a step of analyzing the received signal to detect any missing segment thereof and, as the case may be, to initiate an analysis, within each sub-band, of the segment(s) adjacent to the lost segment, so as to generate a term relating to the period T(k) of the signal so analyzed and to reconstruct a segment of signal of period T(k) intended to be substituted for the lost segment.
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公开(公告)号：CA1227295A
公开(公告)日：1987-09-22
申请号：CA479412
申请日：1985-04-17
Applicant: IBM
Inventor： CALLENS PAUL , GALAND CLAUDE
Abstract: A method of transmitting digitized voice signals as packets of bits in a digital transmission network to which a plurality of terminals acting as sources of voice signals are attached. The method includes, at the transmitting end and for each source, the steps of : dividing the signal into successive, digitally-coded segments; performing a so-called source activity detection; and assembling the bits resulting from the coding operation into packets, each packet being provided with a header containing, in particular, a parity bit whose logic value is modified whenever an inactivity or long pause is detected. At the receiving end, detection of a change in the value of said parity bit causes the delivery of a packet of bits to the decoder/synthesizer to be delayed by a given time interval called retention delay.
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公开(公告)号：DE2512541A1
公开(公告)日：1975-10-30
申请号：DE2512541
申请日：1975-03-21
Applicant: IBM
Inventor： CALLENS PAUL , PICARD JEAN-LOUIS , POULET ALAIN
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