US2408063A - Multiplex receiver - Google Patents

Multiplex receiver Download PDF

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Publication number
US2408063A
US2408063A US547123A US54712344A US2408063A US 2408063 A US2408063 A US 2408063A US 547123 A US547123 A US 547123A US 54712344 A US54712344 A US 54712344A US 2408063 A US2408063 A US 2408063A
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US
United States
Prior art keywords
undulations
pulses
channel
circuit
channels
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 - Lifetime
Application number
US547123A
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English (en)
Inventor
Donald D Grieg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Federal Telephone and Radio Corp
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority to FR954531D priority Critical patent/FR954531A/fr
Priority to BE474666D priority patent/BE474666A/xx
Priority to BE474665D priority patent/BE474665A/xx
Priority to US547123A priority patent/US2408063A/en
Priority to US547125A priority patent/US2429616A/en
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB13869/45A priority patent/GB592779A/en
Priority to GB13868/45A priority patent/GB601129A/en
Application granted granted Critical
Publication of US2408063A publication Critical patent/US2408063A/en
Priority to FR57641D priority patent/FR57641E/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/02—Details
    • H04J3/08—Intermediate station arrangements, e.g. for branching, for tapping-off

Definitions

  • This invention relates to4 multi-channel communication systems and more particularly to the selective reception of a plurality of ltransmitted channels.
  • One of the'objects of this invention is to provide anv improved ⁇ method and means for the selectivereception in a multi-channel communication or broadcasting system of a plurality of intelligence conveying channels, the different channels being distinguishd by different identifying characteristics.
  • a further object Aof the invention is to provide a method and vmeans at the receiving pointsof acommunication' system for selectively receiving any one'or more-of a pluralityof signal channels transmitted in time-,spaced relation over a common transmission medium, such as a transmission line or a given carrier radio frequency Wave.
  • Another object of the invention is to provide methods and means for selective multi-channel reception, wherein signal intelligence is conveyed over each channel by means of a series of pulses which are modulated with respect to any one of a number of their characteristics such as time position, for example, in accordance with the instantaneousV value of the intelligence, and wherein the pulses of the individual channels have different identifying widths.
  • An additional object of the invention includes the provision of a method and means for ⁇ the selective reception of. the respective channels in multi-channel communication systems in accordance with the characteristic pulse Widths-thereof.
  • a number of channels, ⁇ conveying signal intelligence by means of a series of pulses, eachy channel. characterizedby anidentifying pulse width and the pulses of which are modulated with respectto one of their characteristics in accordance with.
  • the signal intelligence to be conveyed are received in time-spaced relation as a single train ofpulses at the receiving terminal and applied to a pulse-width-to-amplitude-translator the incoming pulses, having different widthsifor the various channels, are translatedinto undulations ofzsimilar width, the/amplitudes of which are made to vary as the-widths of the correspondingpulses.
  • the undulations now characteri'Zed-foreach 'channel byV an identifying amplitude may then be fed as a single'train of undulations-'to a' peak riding clipperfandV to one'or more of aplurality of mixer and peak riding clipper circuits, representing, the various channels of Vcommunication respectively.
  • the undulations now characteri'Zed-foreach 'channel byV an identifying amplitude may then be fed as a single'train of undulations-'to a' peak riding clipperfandV to one'or more of aplurality of mixer and peak riding clipper circuits, representing, the various channels of Vcommunication respectively.
  • i'lrsty peak-ridingV clipper circuit In the, i'lrsty peak-ridingV clipper circuit,
  • the clipped portions may also be used to substantially eliminate from: the train of undulations, before the train of undulations is applied l to subsequent peak riding clipper circuits, which. act to successively segregate by clipping of their peak portions, the undulations havingA relative maximum amplitudes in sequential order according to their values.
  • the clipped portions of a given channel or channels having relative -maximum amplitude undulations may be iirst inverted and'thenmixed with the train of undulations from the original 'translator or apreceding channel, whereby the firsty orv preceding maximum amplitude undulations-are substantially cancelled out. This brings in line for segregation by the peak riding clippers in the subsequent channel circuits the undulations of the channel having the second or succeeding maximum amplitude undulations.
  • This principle may be employed to successively eliminate lone channel after another before applying the train of undulations to the peak riding clipper of the next channel.
  • Fig. 1A is a block diagram of a receivingv terminal of a multi-channel communication system according to my invention
  • Fig. 1B is a block diagram of avmodifled form l of thereceivingterminal of Fig. 1A.l
  • Fig. 2 is a schematic circuit diagram ofA a width-to-amplitude translator and of a peakriding clipper circuit of the receiving terminal circuits of Fig. l;
  • Fig. 3 is a graphical illustration of the operakoms of thecircuits of Fig. 2.
  • the third channel includes a similar mixer and peak riding clipper 6.
  • the output of the peak riding clipper 2 is applied to the mixer 3, mixer 5 receiving the output of mixer 3 and that of the peak riding clipper 4.
  • the outputs of the peak riding clippers 2, 4 and 8 may be applied to democlulators, as desired.
  • a further channel ⁇ Il, which is not shown, may be similarly supplied from mixer 5 and clipper Ii, as indicated.
  • the receiving terminal is made u of the same major circuit elements as the form of Fig. 1A, except that in this case, the adjustable translator I feeds all of thevchannel circuits in parallel, and the output of ther peak riding clippers 2, i and 6 are fed into a common connection P, from which the mixers are individually supplied, the various channel circuits beingA separated by de-couplers D. Further channel circuits, as required, may be similarly connected to the translator I and the peak riding clipper connection P. y
  • Fig. 2 illustrates circuit I and 2, as shown in block form in Figs. 1A and 1B.
  • the circuit I is utilized for translating a train of pulses of various widths into undulations having corresponding amplitude Variations, as described, for instance, in the copending application of E. Labin and myself, Serial No. 487,072, likewised May l5, 1943, wherein the circuit isvdisclosed as a pulse selector according to pulse width.
  • the circuit includes a limit clipping stagev 'i as an input coupler, which limits all input pulses to substantially the same amplitude and, also, inverts the input pulses from a positive polarity, as indicated by the pulses of curve a, Fig. 3, to negative polarity indicated by the pulses of curve b.
  • the output pulse energy from stage I is applied through a resistor R to a tuned shock-excitable L.-C. circuit 8.
  • a vacuum tube 9 Connected across the tunable circuit 3 is a vacuum tube 9, the cathode II] of which is connected to the input side of the circuit 8, while its anode II is connected to the opposite side I2 of the tunable circuit.
  • the side I2 is also connected to a source of anode potential at I3.
  • the pulse energy, as in curve b, Fig. 3, from an anode connection I4 of the tube 1 is applied to the grid of the tube 9, so as to block conduction between the cathode Ill and the anode II, while pulse energy is applied to the circuit 8.
  • the undulations, which are produced in circuit 8 in response to pulseenergy coming in over connection I4, are taken 01T through a connection I5 for application to the peak riding clipper stage 2.
  • the undulations in connection I5' arefed over a condenser I6 to a grid I1 of tube I8.”
  • the grid circuit includes aresistor I9 and -abiasing resistor 20, the latter being shunted by the usual by-pass condenser 2
  • connection I5 Branching oi from connection I5 is a connection 2B which serves to feed undulati'ons from the width-to-amplitude translator I to the circuit of channelVv 2 as in Fig. 1A, or to the circuit of channels 2, 3 and others as in Fig. 1B.
  • circuit 8 is tuned for a maximum response, that is for selection of pulse width W1.
  • curve c represents the output of circuit 8 when the circuitis tuned for a maximum response to pulses having the width W1, illustrating a series of output undulations as obtained fromthe different pulse Widths of curve a.v
  • an initial undulation 29 is j produced, Vwhich is normally followed by undulations 38 and 3
  • circuit 8 is tuned to a frequency, the period of which is exactly twice the width W1, the trailing edge of the W1 pulse occurs where the initiated, oscillatory energy crosses the zero axis fromv undulation 29 to the undulation 30. Since the trailing edge of this pulse shock-excites the circuit 8 in the same direction at this point, the undulation 32 produced thereby in circuit 8 adds algebraically to the undulation 30 to produce a resultantundulation 33. The next succeeding pairs of undulations produced by the leading and trailing edges of pulse W1 would normally tend to produce a negative undulation 34, which would tend to continue as a damped wave. Damping tube 9, however, eliminates any such trailing oscillations so that they do not interfere with the undulations produced by subsequent pulses applied to circuit 8.
  • a pulse Width less than pulse Vwidth W1 such, for example, as the width W3 will not produce undulations as great ras undulation 33, if the circuit tuning is adjusted to correspond to pulse Width W1. This is illustrated by undulation 35, produced in response to the pulse width W3.l The reason for this is readily apparent, because shock excitations, produced by the leading and trailing edges of the pulses of lesser width than W1, will in part be opposed to each other.
  • Undulation 36 in response to the greater pulse width W2, is likewise smaller than undulation 33, since here again, the oscillations, produced in response to the leading and trailing edges of theA greater pulse width, are in part opposed-to each other, so that the algebraic summation thereof is less than in the case of undulations produced in response to pulse width'Wi. y
  • Curve c of Fig. 3 therefore represents a series of output undulations corresponding to the train of pulses, as in curve a, which are present in the output connection I5, and which may be fed to the peak riding clipper stage 2 and to mixer 3 as inv Fig, ⁇ 1A,V or in parallel to all channels as in Fig. 1B.
  • This characteristic I make use of by using the clipped peaks of themaximum amplitude vundulations to successively eliminate such maximum undulations whereby the peak riding clipper'circuit in the subsequent channels are enabled to select undulations having the-next highest amplitude, in succession.
  • the clipped peaks, for instance, of undul-ation 33, ind-icated by curve d, may be amplified and inverted in the clipper circuit ⁇ 2, to assume the form as shown in curve e which are then mixed (at mixer3 with the series ofundulations represented in curve c.
  • the resulting series'of undulations, as obtained from mixer 3, is shown in curve f where itis seen that the undulations 33 have now practically disappeared, and undula- 'This train of undulations (curve f) is applied to .the peak riding clipper circuit ll, Fig. 1A, where, automatically, a clipping level 4l is established curve f, and the peaks 42 of the undulations 36 are clipped off as shown in curve g.
  • This output is analogous to that obtained from peak riding clipper 2 for channel I, and may be similarly used to obtain a reproduction of the original signal for channel 2 by demodulation.
  • Portions 42 may also be used to eliminate undulations 36 by inversion and mixing in mixer 5 with the output of mixer 3. This enables peak riding clipper 6 in the circuit of channel 3 to establish 6 automatically a peak .clipping levelcorre'sponding to undulations 35,.which havenow comeltobethe maximum amplitude undulationsjinfthe, series applied to-clipper'.
  • clipper 6 receives the remaining undulation-35Lto acton.
  • l A A Further similar clipping and mixing operations may be employed to obtainfthe-separationof the undulations of additionalchannels.
  • l f It will be apparent that by varying the tuning of the resonant circuit-8 for eiective ⁇ maximum response to other pulse widths, the sequen-ceeofv the selection of thev channels may be changedat wi1l,if desired. Y f 1 ItA is thus seen that by a ⁇ combination of?
  • a method according to claim 1, wherein the ⁇ operation of selecting includes the steps of successively clipping the peaks of the undulations in the order of the values of the amplitudes thereof.
  • a multiplex system forfselectively and simultaneously receiving any. of a number .of chan'- nels of communicationfroml -a ⁇ multi-channel train of-v pulses wherein the pulses of each charinel diiler from. pulses ofother channels ibyia diierent identifying Width; comprisin'gfm'eansior translating saidv pulses,v into a. series. ⁇ of corre.- sponding undulations the amplitude ⁇ of ⁇ which Vary substantially as the respective width ofthe corresponding pulses common to all channels; and for each channel, means for selecting from said series the undulations of a given channel' in accordance with thev relative amplitude thereof.
  • said means for translating includes a vresonant circuit tuned to a frequency having a vperiod proportionate to the'width ofv the pulses of agiven first channeli i s l0.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Filtering Of Dispersed Particles In Gases (AREA)
  • Manipulation Of Pulses (AREA)
US547123A 1944-07-29 1944-07-29 Multiplex receiver Expired - Lifetime US2408063A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
BE474665D BE474665A (fr) 1944-07-29
FR954531D FR954531A (fr) 1944-07-29
BE474666D BE474666A (fr) 1944-07-29
US547125A US2429616A (en) 1944-07-29 1944-07-29 Pulse width multichannel system
US547123A US2408063A (en) 1944-07-29 1944-07-29 Multiplex receiver
GB13869/45A GB592779A (en) 1944-07-29 1945-06-01 Improvements in or relating to multichannel electric pulse communication receivers
GB13868/45A GB601129A (en) 1944-07-29 1945-06-01 Improvements in or relating to electric multi-channel pulse communication systems
FR57641D FR57641E (fr) 1944-07-29 1947-08-07 Systèmes de communication électrique multiplex

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US547123A US2408063A (en) 1944-07-29 1944-07-29 Multiplex receiver

Publications (1)

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US2408063A true US2408063A (en) 1946-09-24

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US547123A Expired - Lifetime US2408063A (en) 1944-07-29 1944-07-29 Multiplex receiver

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US (1) US2408063A (fr)
BE (2) BE474665A (fr)
FR (2) FR57641E (fr)
GB (2) GB601129A (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2469460A (en) * 1945-04-12 1949-05-10 Stanolind Oil & Gas Co Radioactivity measurement
US2477625A (en) * 1944-08-25 1949-08-02 Standard Telephones Cables Ltd Multiplex television and pulse modulated sound system
US2481014A (en) * 1945-03-22 1949-09-06 Texas Co Method and apparatus for radioactivity well logging
US2492344A (en) * 1945-11-14 1949-12-27 Standard Telephones Cables Ltd Line finder control circuit for communication systems
US2539440A (en) * 1945-09-27 1951-01-30 Standard Telephones Cables Ltd Single carrier, sound and color vision pulse system
US2543015A (en) * 1945-09-27 1951-02-27 Standard Telephones Cables Ltd Receiver circuit
US2580421A (en) * 1944-12-23 1952-01-01 Radio Patents Corp Cross-talk compensation in pulse multiplex system
US2647944A (en) * 1946-11-26 1953-08-04 American Optical Corp Single carrier transmission of sound and video signals
US2653231A (en) * 1947-10-13 1953-09-22 Nat Res Dev Amplitude-discriminating circuits
US2777947A (en) * 1946-03-18 1957-01-15 Conrad H Hoeppner Pulse width discriminator
US2870247A (en) * 1950-05-08 1959-01-20 Rca Corp Cross talk eliminating apparatus in a time division multiplex system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1332571A (fr) * 1962-04-09 1963-07-19 Electronique & Physique Circuit de correction aux basses fréquences pour amplificateurs à large bande

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2477625A (en) * 1944-08-25 1949-08-02 Standard Telephones Cables Ltd Multiplex television and pulse modulated sound system
US2580421A (en) * 1944-12-23 1952-01-01 Radio Patents Corp Cross-talk compensation in pulse multiplex system
US2481014A (en) * 1945-03-22 1949-09-06 Texas Co Method and apparatus for radioactivity well logging
US2469460A (en) * 1945-04-12 1949-05-10 Stanolind Oil & Gas Co Radioactivity measurement
US2539440A (en) * 1945-09-27 1951-01-30 Standard Telephones Cables Ltd Single carrier, sound and color vision pulse system
US2543015A (en) * 1945-09-27 1951-02-27 Standard Telephones Cables Ltd Receiver circuit
US2492344A (en) * 1945-11-14 1949-12-27 Standard Telephones Cables Ltd Line finder control circuit for communication systems
US2777947A (en) * 1946-03-18 1957-01-15 Conrad H Hoeppner Pulse width discriminator
US2647944A (en) * 1946-11-26 1953-08-04 American Optical Corp Single carrier transmission of sound and video signals
US2653231A (en) * 1947-10-13 1953-09-22 Nat Res Dev Amplitude-discriminating circuits
US2870247A (en) * 1950-05-08 1959-01-20 Rca Corp Cross talk eliminating apparatus in a time division multiplex system

Also Published As

Publication number Publication date
FR57641E (fr) 1953-03-17
BE474666A (fr)
FR954531A (fr) 1950-01-03
GB601129A (en) 1948-04-28
BE474665A (fr)
GB592779A (en) 1947-09-29

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