公开(公告)号：FR2389277A1

公开(公告)日：1978-11-24

申请号：FR7713995

申请日：1977-04-29

Applicant: IBM FRANCE

Inventor： CROISIER ALAIN ,  ESTEBAN DANIEL ,  GALAND CLAUDE

IPC: H03M1/00 ,  G10L19/02 ,  H03M7/30 ,  H04B1/66 ,  H04B14/04 ,  H03K13/01

Abstract: A coding process, given a total number of available bits per unit time, allocates to each of a plurality of signal channels a number of bits proportional to information in the channel. The process is useful for transcoding BCPCM (Block Coded PCM) voice signals for lower bit rate and conserving transmission channel bandwidth.

公开(公告)号：DE3171990D1

公开(公告)日：1985-10-03

申请号：DE3171990

申请日：1981-04-30

Applicant: IBM ,  IBM FRANCE

Inventor： BERAUD JEAN-PAUL ,  ESTEBAN DANIEL ,  GALAND CLAUDE

IPC: H03M3/02 ,  H03M7/30 ,  H04B1/66 ,  H04B14/04

Abstract: This improved speech signal Block Coded PCM (BCPCM) system reduces the number of bits allocated to transmitting the scale factor, thereby releasing bits for allocation to coding samples in the associated block of samples. The scale factor (c) is calculated for every 16 millisecond block of samples. However, the scale factor will be transmitted only once per 32 millisecond block if there is no significant difference between the two sequential values. The original speech signal is split into 16 frequency subbands, each subband initials sampled and 12-bit coded, then requantized in BCPCM at dynamically variable bit rates depending on the scale factor transmission rate.

公开(公告)号：FR2331207A2

公开(公告)日：1977-06-03

申请号：FR7534716

申请日：1975-11-05

Applicant: IBM FRANCE

Inventor： ESTEBAN DANIEL ,  TEMIM JEAN-PIERRE

IPC: H03M3/04 ,  H03M7/30 ,  H03M7/32 ,  H04B14/04 ,  H03K13/02

公开(公告)号：FR2312884A1

公开(公告)日：1976-12-24

申请号：FR7517189

申请日：1975-05-27

Applicant: IBM FRANCE

Inventor： ESTEBAN DANIEL ,  MENEZ JEAN

IPC: H03M1/12 ,  H03M1/00 ,  H03M3/02 ,  H03M3/04 ,  H03M7/30 ,  H03K13/02

Abstract: 1506361 Block quantization process INTERNATIONAL BUSINESS MACHINES CORP 31 March 1976 [27 May 1975] 12971/76 Heading H3H To minimize error in quantizing a section Sn of N samples of a signal to be represented as where Fn is a bit stream, Q is the quantizing step and Cn a constant or polynomial, the final values of Cn and Q are arrived at iteratively. For one bit quantization a section of samples Sn‹ is loaded on to a recirculating delay line DL1 and presented to a summing point ADD 1 where an initial value Cn‹ gives Sn 1 = Sn‹ - Cn‹, fed to device QUANT producing sign derived bit stream Fn' which together with Sn' is fed to device COMP. This computes values of Cn and Q to minimize error where p is 2 for quadratic error. A new stream Fn is then calculated and the system iterates to reduce errors. For more than onebit quantization device QUANT uses the value of Q to determine Fn. A delta modulation embodiment is described, Fig. 5 (not shown), where the signal encoded Sn is the difference between an incoming signal Xn i and reconstructed signal Xn i-1 .