US4589130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multirate digital transmission method and device for implementing said method
Assignee: International Business Machines Corp
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Filing: 1983-01-18
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Granted: 1986-05-13
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Expires: 2003-01-18
Abstract
Abstract In a TASI system using dynamic subband allocation and BCPCM (Block Companded PCM), losses due to freeze-out or delay are avoided by use of a multi-rate macro-frame format, wherein switching to a lower rate (24, 16, or 8 Kbs) for one or more of the input channels is accommodated by simply dropping one or more sections of each signal frame, since the lower rate bits are distributed over the entire frame.
Inventors
- 👤 Claude Galand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:03
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/66; H04B1/667; G; G10; G10L; G10L19/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
188 words
A method for digitally coding an electric signal for subsequent transmission at one of a plurality of different rates and in which said signal is sampled at a predetermined frequency and sub-band coded by dynamically allocating the coding bits to the sub-bands, the coding rate for all sub-bands being selected to conform to the highest rate in a set of predetermined rates, said method including the steps of: generating a macro-sample frame format for regrouping the bits obtained by coding all samples taken in all the sub-bands during the same sampling instant, said frame format being divided in a number of fields corresponding to the number of different bit rates in the set of bit rates; generating for each sampling instant a multi-rate macro-sample by distributing amongst said fields the bits obtained by coding each sample in the said macro-sample, according to the weight of the said bits and their distribution among the sub-bands, with reference to each of said rates in the said set; and, adjusting the signaling rate by truncating the said multi-rate macro-sample by dropping predetermined fields as a function of the selected bit rate.
Claim 2
Independent Claim
188 words
A method for digitally coding an electric signal for subsequent transmission at one of a plurality of different rates and in which said signal is sampled at a predetermined frequency and sub-band coded by dynamically allocating the coding bits to the sub-bands, the coding rate for all sub-bands being selected to conform to the highest rate in a set of predetermined rates, said method including the steps of: generating a macro-sample frame format for regrouping the bits obtained by coding all samples taken in all the sub-bands during the same sampling instant, said frame format being divided in a number of fields corresponding to the number of different bit rates in the set of bit rates; generating for each sampling instant a multi-rate macro-sample by distributing amongst said fields the bits obtained by coding each sample in the said macro-sample, according to the weight of the said bits and their distribution among the sub-bands, with reference to each of said rates in the said set; and, adjusting the signaling rate by truncating the said multi-rate macro-sample by dropping predetermined fields as a function of the selected bit rate.
Claim 3
Dependent Claim
103 words
A multi-rate coding method according to claim 1, wherein the signal is coded using so-called BCPCM techniques for coding the signal by blocks of successive samples representing a predetermined signal segment, each of said segments supplying a characteristic term with respect to which the samples of said segment are coded, said method including: reserving a predetermined number of bits for coding the characteristic terms of each block of samples, said rates in said set of predetermined rates being reduced accordingly; regrouping the bits resulting from the coding of the characteristic terms of each block within the same macro-sample field called characteristic block field.
Claim 4
Dependent Claim
35 words
A multi-rate coding method according to claim 2, characterized in that the bits resulting from each coded block of samples are arranged to have the characteristic block field followed by macro-samples of the same block.
Claim 5
Dependent Claim
38 words
A coding method according to claim 2, further characterized in that each block of samples is arranged in accordance with a format that regroups the bits of similar fields of all macro-samples of the same block of samples.
Claim 6
Dependent Claim
34 words
A digital coding method according to any one of claims 2 to 4 wherein said BCPCM type of sub-band coding is operated over the whole frequency spectrum of a voice signal to be transmitted.
Claim 7
Dependent Claim
31 words
A coding method according to any one of claims 2 to 4, characterized in that said sub-band coding is operated over a portion of the frequency spectrum of a voice signal.
Claim 8
Dependent Claim
23 words
A coding method according to claim 6, characterized in that said portion of the spectrum corresponds to the baseband of the voice signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |