GB1039822A - Signal transmission system - Google Patents
Signal transmission systemInfo
- Publication number
- GB1039822A GB1039822A GB928564A GB928564A GB1039822A GB 1039822 A GB1039822 A GB 1039822A GB 928564 A GB928564 A GB 928564A GB 928564 A GB928564 A GB 928564A GB 1039822 A GB1039822 A GB 1039822A
- Authority
- GB
- United Kingdom
- Prior art keywords
- signal
- band
- speech
- level
- original
- 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
- 230000008054 signal transmission Effects 0.000 title 1
- 230000005540 biological transmission Effects 0.000 abstract 2
- 238000010586 diagram Methods 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
- 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
- H04B1/62—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 providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
- H04B1/64—Volume compression or expansion arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (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)
- Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
- Transmitters (AREA)
Abstract
1,039,822. Transmission systems; pulse modulation systems. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 5, 1964 [March 18, 1963], No. 9285/64. Headings H4L and H4R. A complex wave, e.g. speech, is transmitted by adding to the wave a constant amplitude reference signal of a frequency outside the frequency band of the complex wave and limiting the resulting signal to obtain a rectangular waveform of constant amplitude and having zero crossings corresponding to the zero crossings of the sum signal. The resulting rectangular wave has the same power-frequency distribution as the original waves but, due to the limiting, the total power has been made constant. At the receiver the complex wave band and the reference signal band are separated and the level of the complex waveband adjusted in accordance with the change in level of the reference signal band so as to restore the original power level to the complex waveband and thus restore the complex wave to its original form. Fig. 1 shows a block diagram of the system in which a signal from the transducer 10 is fed via a pre-emphasis network 12 and a band-pass filter 14 to a summing amplifier 18 where it is added to a reference signal from generator 16. The sum signal may then be modulated to a higher frequency band in device 20 in order that after clipping in limiter 22 the modulation products, which might cause distortion in the speech, lie outside the speech frequency band. The resulting clipped waveform is transmitted to the receiver by means 24 which may include a demodulator if the signal was modulated before clipping. The transmission may be by amplitude modulation of a carrier or the signal may be transmitted as a pulse train. At the receiver the original speech signal is recovered by decoder 26 and de-emphasis network 28. Three forms of decoder are described; in one, Fig. 2, the speech components are separated from the sum signal by band-pass filter 34 and applied to the dividend input of a divider circuit 38, the reference signal is separated by the band-pass filter 32, its envelope detected, and the resulting signal applied to the divisor input of the dividing circuit the output from which, after de-emphasis, is a replica of the original speech. In a second embodiment, Fig. 3, the speech components from filter 40 are applied to a variablegain amplifier, 42, the gain of which is controlled in accordance with the deviations of the level of the received reference signal components from envelope detector 46 as compared with a comparison reference level from generator 48 as determined in difference amplifier 50. In an alternative form, Fig. 4 (not shown), the variable gain amplifier acts on the sum signal which is then applied to the speech component and reference component band-pass filters, the output from the reference component filter being fed back to control the amplifier gain to tend to maintain the reference component level constant, the signal component then being restored to its original form.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US26589063A | 1963-03-18 | 1963-03-18 | |
US532028A US3327063A (en) | 1966-01-14 | 1966-01-14 | Transmission of information in powercoded bipolar waveforms |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1039822A true GB1039822A (en) | 1966-08-24 |
Family
ID=26951481
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB928564A Expired GB1039822A (en) | 1963-03-18 | 1964-03-05 | Signal transmission system |
GB4711566A Expired GB1151270A (en) | 1963-03-18 | 1966-10-21 | Signal Transmission Systems |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB4711566A Expired GB1151270A (en) | 1963-03-18 | 1966-10-21 | Signal Transmission Systems |
Country Status (3)
Country | Link |
---|---|
DE (2) | DE1222119C2 (en) |
FR (1) | FR93357E (en) |
GB (2) | GB1039822A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4545065A (en) * | 1982-04-28 | 1985-10-01 | Xsi General Partnership | Extrema coding signal processing method and apparatus |
-
1964
- 1964-03-05 GB GB928564A patent/GB1039822A/en not_active Expired
- 1964-03-18 DE DE1964J0025476 patent/DE1222119C2/en not_active Expired
-
1966
- 1966-10-21 GB GB4711566A patent/GB1151270A/en not_active Expired
- 1966-12-21 DE DE19661487342 patent/DE1487342B2/en active Pending
-
1967
- 1967-01-11 FR FR06008287A patent/FR93357E/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE1222119C2 (en) | 1974-03-07 |
DE1487342B2 (en) | 1973-06-20 |
DE1487342A1 (en) | 1969-03-27 |
DE1222119B (en) | 1966-08-04 |
GB1151270A (en) | 1969-05-07 |
FR93357E (en) | 1969-03-21 |
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