GB1501874A - Telecommunications apparatus - Google Patents
Telecommunications apparatusInfo
- Publication number
- GB1501874A GB1501874A GB25475/74A GB2547574A GB1501874A GB 1501874 A GB1501874 A GB 1501874A GB 25475/74 A GB25475/74 A GB 25475/74A GB 2547574 A GB2547574 A GB 2547574A GB 1501874 A GB1501874 A GB 1501874A
- Authority
- GB
- United Kingdom
- Prior art keywords
- time interval
- decoder
- amplitude
- coder
- code
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000005540 biological transmission Effects 0.000 abstract 3
- 238000005070 sampling Methods 0.000 abstract 2
- 230000001788 irregular Effects 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/66—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission for reducing bandwidth of signals; for improving efficiency of transmission
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
- G10L25/00—Speech or voice analysis techniques not restricted to a single one of groups G10L15/00 - G10L21/00
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M1/00—Analogue/digital conversion; Digital/analogue conversion
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M1/00—Analogue/digital conversion; Digital/analogue conversion
- H03M1/12—Analogue/digital converters
- H03M1/34—Analogue value compared with reference values
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Theoretical Computer Science (AREA)
- Computational Linguistics (AREA)
- Health & Medical Sciences (AREA)
- Audiology, Speech & Language Pathology (AREA)
- Human Computer Interaction (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Computer Networks & Wireless Communication (AREA)
- Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
Abstract
1501874 Speech transmission DEFENCE SECRETARY OF STATE FOR 3 June 1975 [7 June 1974] 25475/74 Heading H4R In a pulse code modulation system, the logarithmically compressed amplitudes of, and time intervals between, successive stationary points (maxima and minima) of an input analogue waveform are encoded, and the decoder includes a filter whose response time is controlled in accordance with the received time interval signals. Coder.-Stationary points are detected by a differentiator 2 and zero cross detector 4 which controls the sampling instants for the amplitude coder 6 and the time interval coder 7, either or both of which may have a compressive characteristic. Decoder.-Timer 15 controls read out of time interval and amplitude codes from buffer 13 in accordance with the time interval codes. Amplitude decoder 17 produces a stepped wave analogue output in which each level has a duration corresponding to a respective time interval code and this stepped wave is smoothed in a second order controllable filter 19, details Fig. 3 (not shown) comprising impedances which are switched in and out of circuit with a variable duty-cycle determined by the time interval decoder 16 to match the rise time of the filter to the duration of each step in the output of the amplitude decoder 17. Transmission link.-In order that the P.C.M. signals may be transmitted at a predetermined regular bit rate, despite irregular sampling, buffer stores 8, 13 are provided and the transmission link has a slight excess capacity. When multiplexer 9 finds an empty store location, a zero time interval code is transmitted together with a repetition of the previous amplitude code.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB25475/74A GB1501874A (en) | 1975-06-03 | 1975-06-03 | Telecommunications apparatus |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB25475/74A GB1501874A (en) | 1975-06-03 | 1975-06-03 | Telecommunications apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1501874A true GB1501874A (en) | 1978-02-22 |
Family
ID=10228315
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB25475/74A Expired GB1501874A (en) | 1975-06-03 | 1975-06-03 | Telecommunications apparatus |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1501874A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0004759A2 (en) * | 1978-04-04 | 1979-10-17 | National Research Development Corporation | Methods and apparatus for encoding and constructing signals |
FR2524225A1 (en) * | 1982-03-26 | 1983-09-30 | Victor Company Of Japan | METHOD AND SYSTEM FOR DECODING A DIGITAL SIGNAL USING A LOW-PASS FILTER FOR VARIABLE FREQUENCY |
EP0093190A1 (en) * | 1982-05-05 | 1983-11-09 | Arie Visser | Extrema coding signal processing method and apparatus |
US4545065A (en) * | 1982-04-28 | 1985-10-01 | Xsi General Partnership | Extrema coding signal processing method and apparatus |
US4652857A (en) * | 1983-04-29 | 1987-03-24 | Meiksin Zvi H | Method and apparatus for transmitting wide-bandwidth frequency signals from mines and other power restricted environments |
EP0491840A1 (en) * | 1989-09-13 | 1992-07-01 | Datajet, Inc. | Signal digitizing method and system |
FR2697388A1 (en) * | 1992-10-22 | 1994-04-29 | Eurodat | Dynamic Analogue=digital converter - includes sample=and=hold circuit and comparator comparing successive values of signal, with comparator output values stored with related times |
-
1975
- 1975-06-03 GB GB25475/74A patent/GB1501874A/en not_active Expired
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0004759A2 (en) * | 1978-04-04 | 1979-10-17 | National Research Development Corporation | Methods and apparatus for encoding and constructing signals |
EP0004759A3 (en) * | 1978-04-04 | 1979-10-31 | Harold William Gosling | Methods and apparatus for encoding and constructing signals |
US4382160A (en) | 1978-04-04 | 1983-05-03 | National Research Development Corporation | Methods and apparatus for encoding and constructing signals |
FR2524225A1 (en) * | 1982-03-26 | 1983-09-30 | Victor Company Of Japan | METHOD AND SYSTEM FOR DECODING A DIGITAL SIGNAL USING A LOW-PASS FILTER FOR VARIABLE FREQUENCY |
US4673916A (en) * | 1982-03-26 | 1987-06-16 | Victor Company Of Japan, Limited | Method and system for decoding a digital signal using a variable frequency low-pass filter |
US4545065A (en) * | 1982-04-28 | 1985-10-01 | Xsi General Partnership | Extrema coding signal processing method and apparatus |
EP0093190A1 (en) * | 1982-05-05 | 1983-11-09 | Arie Visser | Extrema coding signal processing method and apparatus |
US4652857A (en) * | 1983-04-29 | 1987-03-24 | Meiksin Zvi H | Method and apparatus for transmitting wide-bandwidth frequency signals from mines and other power restricted environments |
EP0491840A1 (en) * | 1989-09-13 | 1992-07-01 | Datajet, Inc. | Signal digitizing method and system |
EP0491840A4 (en) * | 1989-09-13 | 1994-11-02 | Datajet Inc | Signal digitizing method and system |
FR2697388A1 (en) * | 1992-10-22 | 1994-04-29 | Eurodat | Dynamic Analogue=digital converter - includes sample=and=hold circuit and comparator comparing successive values of signal, with comparator output values stored with related times |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB1501874A (en) | Telecommunications apparatus | |
IT1181481B (en) | Steaming oven | |
IT1181054B (en) | Bread baking oven | |
IT1181211B (en) | Eggs grading equipment | |
IT1181047B (en) | Gold and silver recovery | |
IT1181561B (en) | Salt elimination from greased leather | |
IT1181617B (en) | Smoke producing target rocket | |
IT1181135B (en) | Enamelling chamber | |
IT1181342B (en) | Cheese consolidation tub | |
IT1181455B (en) | Metal casting equipment protection | |
IT1181325B (en) | Single use plastic syringe | |
IT1181468B (en) | Chlorella based cosmetic compsn. | |
IT1181542B (en) | Wine champagnisation autoclave | |
IT1181957B (en) | Automatic injection gun | |
IT1181120B (en) | Automatic dosimeter for expresso coffee machine | |
IT1181482B (en) | Chestnut roasting and stripping equipment | |
IT1181488B (en) | Emptying system for explosives containers and bombs | |
IT1181119B (en) | Expresso machine infusion system | |
IT1181358B (en) | Shaped metal articles welding system | |
IT1181301B (en) | Wax for false teeth prodn. | |
IT1181500B (en) | Liquid tanning waste collection system | |
IT1181480B (en) | Bread dough leavening plant | |
IT1181940B (en) | Industrial wastes processing | |
IT1181535B (en) | Vulcanising plant | |
IT1181467B (en) | Dough pieces forming equipment |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |