US2474244A - Amplitude modulated time modulated pulse system - Google Patents

Amplitude modulated time modulated pulse system Download PDF

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Publication number
US2474244A
US2474244A US536301A US53630144A US2474244A US 2474244 A US2474244 A US 2474244A US 536301 A US536301 A US 536301A US 53630144 A US53630144 A US 53630144A US 2474244 A US2474244 A US 2474244A
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United States
Prior art keywords
pulses
channel
station
intelligence
modulated
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Expired - Lifetime
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US536301A
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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
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Standard Telephone and Cables PLC
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Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to US536301A priority Critical patent/US2474244A/en
Priority to GB18204/45A priority patent/GB596051A/en
Priority to BE473447D priority patent/BE473447A/xx
Priority to FR57635D priority patent/FR57635E/fr
Priority to FR57665D priority patent/FR57665E/fr
Application granted granted Critical
Publication of US2474244A publication Critical patent/US2474244A/en
Anticipated expiration legal-status Critical
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    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/155—Ground-based stations
    • H04B7/17—Ground-based stations employing pulse modulation, e.g. pulse code modulation

Definitions

  • This invention relates to pulse communication systems, especially multi-channel systems, incorporating relay and in and out branching stations.
  • P. T. M. pulse time modulation
  • P. A. M. Pulse amplitude modulation
  • P. T. M. pulses may be substantially distorted and attenuated as regards amplitude and yet serve kto adequately convey the intelligence represented by that type of modulation. Therefore P. T. M. may be used over much longer distances than ⁇ P. A. M. without adverse effects. Moreover if 4the distances are so great as to require amplification of the P. T. M. pulses, then relatively inexpensive non-linear relay equipment may be employed.
  • P. T. M. is suitable for long distance transmission
  • P. A. M. is not, unless expensive linear relay stations are employed.
  • This statement applies whether the communication is carried on by co-mmon line transmission, carrier wave line transmission, through a radio link, .or otherwise.
  • the actual physical distance-implied by these terms depends upon the communication medium and other factors such as ⁇ the frequency, power, and equipment employed.
  • An object of the present invention is the provision of ak communication vsystem which makes eicient Ause of the combination of P. A. M. and P. T. M. In one yform this is accomplished by using P.- TLM.I for lon-gA distance transmission and superimposing P--A.,M. :on the P; T. M. pulses to provide additional channels for ⁇ communication over lesser intermediate distances, which .lesser distances maybe short distances .in the special sense. hereinabove .defined,for may be greater than said-short distances .where theamount of .traic warrants the use of linear repeaters.
  • .Anotherobject of thepresent Ainvention is the provision .of...a communication system including two. stations' between -which communication is held by.. P..'T.M.,.said..system including a relay station fonsaid. P. .T. M.communication, which relay station is adapted to have additional communication lwith eithery another similar relay stationor with one of said P. T. stationsbymeans of P. A. M. carried on the P.,T. M. pulses.
  • Another object of the present Vinvention is the provision of -a-.mult'i-ohannel pulse communication system in whichcommunication is carried onbetween two mainstations byv AP. T. M. pulses, and additionalcommunication is carried on between one ormoreintermediate relay and in and out branching .stations..and .any -other station by means of P. A. .M..carried.by, the P. T. M. pulses.
  • FIG..2. fis. a schematicand blockdiagram of a relay Vunit for ,use with .a .single ⁇ channel of pulses in 4accordance ⁇ with .my invention
  • Fig..3 is a schematicandblock diagram of a relay unit .for-ruse 'with multi-channel pulses;l and Fig. 4 is 4a .setofcurvestowhich reference is made in the following..description It is to be understood thatthese curves and others shown .in -thedrawingsare-not drawn toscale and only .have signicance to :the extent :pointed out herein.
  • P. T. M. modulator Any suitable known type of P. T. M. modulator may be used, it being considered suicient to point out that pulses may be displaced in time within the limits indicated by the dotted lines 6.
  • the P. T. M. pulses transmitted from west station I which are modulated with intelligence at said station may be transmitted over long distances and if the distances are suiciently long, non-linear repeaters I may be inserted in the sections 8 of the line covering said long distances.
  • the fact that repeaters 'I are non-linear will not materially affect the communication by P. T. M. pulses.
  • the pulses arrive at a station 9 which, for purposes of conciseness, shall be termed a relay station.
  • the P. T. M. pulses 5 are amplied and transinitted over a short distance line section IB to another relay station I I It may be desired to carry on local communication between relay stations 9 and II and for this purpose the P. T. M.
  • pulses which are relayed as station 9 may be pulse amplitude modulated 4by means such as described hereinafter to carry additional intelligence to station I I as illustrated by pulses I2.
  • the pulses I2 are treated so as to remove the P. A. M. and derive the information represented ⁇ thereby.
  • the P. T. M. pulses are sent on towards east station 2.
  • P. T. M. pulses transmitted from station II to station 2 may again be amplitude modulated with additional intelligence as represented by pulses I3.
  • section I4 of the lines between station Il and station 2 is greater than a short distance, repeaters may be necessary. Since sections I4 are to carry P. A. M. as well as P. T. M., it will be necessary to use linear repeaters I5 for this purpose. At east station 2 the intelligence carried by the P. A. M. and the separate intelligence carried by the P. T. M. of pulses I3 may be derived from said pulses by any known forms of P. T. M. and P. A. M. demodulators.
  • a relay and in and out branching unit I6 for a single channel which unit may be employed in any one lof the stations.
  • This unit is designed to receive pulses I'I having both P. A. M. and P. T. M. Pulses II are fed through a decoupling amplier I8 and a low-pass lter I9 to an indicating device such as a receiver 20. In the lowpass lter I9, the pulses are integrated so as to yield a resultant wave 2I representing the intelligence with which pulses I'I were amplitude modulated.
  • Pulses I'I are also sent through a limit clipper amplier 22 where they are clipped yalong the level 23 and amplified and inverted to produce pulses 24. Pulses 24 still carry the intelligence represented by their time modulation but they have no amplitude modulation.
  • the domodulator 2 serves to translate the time displacement of pulses into amplitude displacements.
  • the low-pass lter 2'! serves to eliminate any high frequency components.
  • unit E6 is also used as a P. T. M. in branching station, then switch 29 is also closed and pulses 39, produced by a P. T. M. modulator ⁇ 3i such for example as disclosed in the aforementioned Patent No. 2,266,401, and time-modulated by a signal from a source 32, are fed through the circuit including switch 29 to an amplitudemodulating circuit 33.
  • the wave generator 3ft for producing a control wave for modulator 32 may be synchronized by means of pulses 24 so that the pulses will have the same timing as the pulses I 'I in the absence of time modulation.
  • unit I6 is not to be used as a P. T. M. in branching and out branching station then switch 35 is closed While switches 25 to 29 remain open. In this case pulses 24 are relayed. When switch 29 is closed and switch 35 open, then pulses 39 are transmitted.
  • Either pulses 24 or the pulses S are fed through an amplitude modulating circuit 33 having a tube 36 where the pulses are amplitude modulated with a signal 31 from a source 38 which may be a microphone or the like to thereby produce pulses 39 which carry both P. T M. and P. A. M.
  • the pulses 24 or 30 are fed to grid 40 of tube 36 while signal 37 is fed to screen grid 4I of tube 36.
  • the pulses 24 and signal 31 combine to produce pulses 39 in the anode circuit 3B.
  • the unit of Fig. 2 thus, not only amplies and relays the P. T. M. pulses, but also removes P. A. M. from received pulses and adds by amplitude modulation further intelligence to the output pulses.
  • the unit may also be used to demodulate the P. T. M. of the pulses, if desired, and to introduce a new series of P. T. M. pulses. Since the unit is intended to handle only one way traic, two of such units may be employed in relay station II to handle two way traffic.
  • multichannel units such as unit 43 illustrated in Fig. 3 and described in connection with the curves of Fig. 4 may be employed.
  • One such unit sufces where one Way traffic is handled and two of such units are used for two way traino.
  • nl three channels si; 5,5. 'andn st are-li11ustrated.
  • Channel '5d of Fig. 4 is the selected channel which has4 been modulated with a distinct id ntifyg characteristicas indicated byfits 'great pulse width.' This distinct width characterisf jisfusedfto provide synchronizatin 1for' theseparationof the various channels.
  • Thefchannel selectory 581s adapted tosele'ct pulsesfaccerding'rto 4their width and is tuned to select puls'esoffthe channel having the distinct widltl'"'cl1a cterisitic'fused for.
  • the channel selector 58 which Aselects pulses according to their width may be'ovf any'flnown type,4 and may be of the form disclosed'finthe,co-pending application of E. Labinl and applicant. Serial No. 487,072, led May 15,1943,A issued 4U. S. Patent crimination between two given' pulsefwidthsmay be accomplished by any oneoffsevr'al well known pulse width discriminators.v
  • the output o'fithe lchannelselector V58 may be represented by the train of pulses illustrated in curve 45. which is produced i bythe' pulses of channel 54.
  • the pulses ⁇ ofa'zurvev l5 are shown delayed for' a slightfinterval in relation tothe pulses ofchannel 54 .toallow for anyydelay that mightoccur during the ⁇ selction' process. Itwill ⁇ be understood, of course, that the selector'may be of the type capable offs'election Without dei" laying the selectedipulseenergy. Any'delay, however, is ofno particular significance since delay devices are required, asvvill be' described hereinafter which are used to selected pulse energy..
  • the pulses of curve .fidare used to separate the various channels but in order to dso; itis preferablethat these pulsesbeshaped .to 'greaterwidth properly tinithe and greater amplitude.
  • Fonthislp'urpose the pulses of curve1l5 ⁇ are sent throughashape'r 59- which may be a multivibrator or any other known type of shape?A Which will produce the desired effects.
  • Thev output oi ⁇ Shaper, 59 represented by curve 136,-, and thepulses there represented willl be hereinafter calledV separating pulses.
  • The'Y separatmg.. pulses; (curve 46).'. are fed through a series of delay devces, 6l, and 62,. each of said devices v,Serving to delay the separating pulses a ljlurtlfier. amount.,
  • the ,devices are p lr'eierably adjustable, yit being understood .'that..
  • justableffeaturez allowsjchoice of channel.; A'They outputfoffeach oisaiddeviceslilD- 6l, and.. ⁇ iL-is7 fed-toA minerslili,y 6.4i; andflid' ⁇ respectively.
  • the mixerI 63 includes a tubey 65 onwhose grid fltlieincoming train of pulses shown incurve le'is'impress'ed.
  • the tube 66 ⁇ also has a'seeond, grid 68 on which the separating pulsesfromdelay device Sil yare likewise impressed.
  • the pulses of channel haare given agreater, ampli; tude than the pulses ofother channels.
  • Tube 65.: is biased .tocut-'ofi below the'level 6.9 of curve Llll,
  • Mixers l6d and toperate in asimilarmanner Mixers l6d and toperate in asimilarmanner.
  • each.orselectedones ⁇ of the channels maybe treatedfso vasto remove, the amplitude modulation and derive the'intelliguencelrepresen'tedwthereby. amplify the P. T. M. pulses, andadd thereto further intelligence ⁇ A as P.- A..
  • the?. T.l M. ofA selected channels may be removed and new channels'of P. T. M. substitutedY inV synchronism in their plates. ⁇ Where new P. T.-
  • channels are' to' 'be substitutedifoi Fig. 2, it is important substitute channel pulses before time'modulation is thesame as tlieunmolulated timing of the.
  • Theoutput of unitsll, 12,and '13 are delivered to a miner 'ille-which serves to interleave the pulses of the various channels to produce a single train of interleaved pulses.
  • themixer 'lll is thenvdeliver'ed to the transmissiony means which may consist-of .a common lline4 l5,-l
  • a communication system including a plurality o stations, means for communicating intelligence between two of said stations by the use of discrete time modulated pulses, said means including a relay station for amplifying and relaying said time modulated pulses, and means at said relay station for communicating additional intelligence between said relay station and one of said stations by superimposed amplitude modu- A lation of said time modulated pulses comprising a source of intelligence signals and means for amplitude modulating said pulses with said signais.
  • a communication system including a pair of communicating stations, means including two relay stations spaced from said communicating stations for relaying intelligence between said communicating stations by the use of time modulated pulses, and means for communicating additional intelligence between said relay stations by superimposed amplitude modulation of said time modulated pulses.
  • a communication system including a plurality of stations, means for communicating intelligence between two of said stations by the use of time modulated pulses, said means including a relay station for relaying said time modulated pulses, one of said two stations including means for amplitude modulating said time modulated pulses superimposed in accordance with additional intelligence, said relay station including means for removing and demodulating the amplitude modulation of said time modulated pulses to derive the additional intelligence represented thereby.
  • a relay station adapted to receive pulses time modulated in accordance with intelligence and amplitude modulated in accordance with additional superimposed intelligence, means for removing the amplitude modulation of said pulses and deriving the additional intelligence represented in said amplitude modulation, means for amplitude modulating the time modulated pulses in accordance with other intelligence, and means for relaying the resulting doubly modulated pulses.
  • a relay station adapted to receive a plurality of pulses representing more than one channel, the pulses of at least one channel being time modulated with intelligence, means for separating the pulses of said one channel from the pulses of other channels, means for amplitude modulat ing the pulses of said one channel with additional superimposed intelligence, means for reinserting the pulses of said one channel among the pulses of the other channels, and means for relaying the pulses of the various channels.
  • a relay station adapted to receive a plurality of pulses representing more than one channel, the pulses of at least one channel being time modulated with intelligence and amplitude modulated With additional superimposed intelligence, means for separating the pulses of said one channel from the pulses of other channels, means for removing the amplitude modulation of the separated pulses, and means for reinserting the pulses representing said one channel among the other channels and relaying the pulses of the various channels.
  • a relay station as set forth in claim 6, including in addition means for amplitude modulatine' with other intelligence the separated pulses of said one channel before reinsertion of said pulses among the pulses of the other channels.
  • a relay station adapted to receive a plurality of pulses representing more than one channel, the pulses of at least one channel being time modulated with intelligence, means for separating said one channel for out branching purposes, means time controlled by the pulses of said out branching channel for generating pulses and time modulating said generated pulses in accordance with other intelligence, means to amplitude modulate said last-mentioned pulses in accordance with additional superimposed intelligence, means to reinsert said last-mentioned pulses amongst the pulses of other channels in place of the separated pulses, and means for relaying pulses of various channels.
  • a relay station adapted to receive a plurality of pulses representing more than one channel, the pulses of at least one channel being time modulated with intelligence and amplitude modulated with additional superimposed intelligence, means for separating the pulses Of said one channel for out branching purposes, means time controlled by the pulses of said out branching channel for generating pulses and time modulating said pulses in accordance with intelligence, means for inserting said last-mentioned pulses among the pulses of other channels in place of the separated pulses, and means for relaying the pulses of various channels.
  • a relay station in addition means for also amplitude modulating the generated pulses in accordance with other intelligence superimposed before insertion of said pulses among the pulses of other channels.
  • a multi-channel pulse communication system including a plurality of stations, means for communicating intelligence between two of said stations by multi-channel time modulated pulses, said means including two relay stations for relaying said multi-channel time modulated pulses, means for communicating additional intelligence between said relay stations, said lastmentioned means including means for separating the pulses of one of said channels from the pulses of other of said channels, and means for superimposedly amplitude-modulating the pulses of the separated channel.
  • a multi-channel communication system including a plurality of stations, means for communicating intelligence between two of said stations by the use of multi-channel time modulated pulses, said means including a relay station for relaying said time modulated pulses, and means for communicating additional intelligence between said relay station and another of the stations of the communication system, said lastmentioned means including means for separting the pulses of one of said channels from the pulses of other of said channels, and means for superimposedly amplitude-modulating the separated pulses.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Time-Division Multiplex Systems (AREA)
US536301A 1944-04-07 1944-05-19 Amplitude modulated time modulated pulse system Expired - Lifetime US2474244A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US536301A US2474244A (en) 1944-05-19 1944-05-19 Amplitude modulated time modulated pulse system
GB18204/45A GB596051A (en) 1944-05-19 1945-07-16 Improvements in or relating to electrical pulse communication systems
BE473447D BE473447A (enrdf_load_stackoverflow) 1944-05-19 1947-05-23
FR57635D FR57635E (fr) 1944-04-07 1947-08-06 Systèmes de communications radioélectriques
FR57665D FR57665E (fr) 1944-04-07 1947-08-06 Systèmes de communications radioélectriques

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US536301A US2474244A (en) 1944-05-19 1944-05-19 Amplitude modulated time modulated pulse system

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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2583484A (en) * 1945-12-15 1952-01-22 Radio Patents Corp Combined angular velocity and pulse modulation system
US2611826A (en) * 1947-06-05 1952-09-23 Kalfaian Meguer Simultaneous amplitude modulation and phase modulation with economy in bandwidth
US2662116A (en) * 1949-12-31 1953-12-08 Potier Gaston Xavier-Noel Double modulated pulse transmission
US2680153A (en) * 1949-01-14 1954-06-01 Philco Corp Multichannel communication system
US2716217A (en) * 1950-07-29 1955-08-23 Raytheon Mfg Co Communication system
US2824908A (en) * 1952-08-07 1958-02-25 Du Mont Allen B Lab Inc Television system method and apparatus for multiplex signaling
US2918665A (en) * 1955-04-08 1959-12-22 Gilfillan Bros Inc Modulation method and system
US2953644A (en) * 1956-10-04 1960-09-20 Bell Telephone Labor Inc Wave transmission system
DE1117643B (de) * 1958-08-06 1961-11-23 Siemens Ag Schaltungsanordnung zur multiplikativen Mischung zweier elektrischer Signale
US3020349A (en) * 1954-12-03 1962-02-06 Int Standard Electric Corp Electric pulse modulating and demodulating circuits
US3078449A (en) * 1958-09-24 1963-02-19 Cons Electrodynamics Corp Commutating and modulating apparatus
US3167614A (en) * 1959-03-16 1965-01-26 Rca Corp Multiplicative stereophonic sound signalling system
US3286521A (en) * 1964-03-26 1966-11-22 Kennecott Copper Corp Wind direction and velocity recording system

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2045107A (en) * 1932-12-02 1936-06-23 Rca Corp Phase modulation
US2075071A (en) * 1932-07-23 1937-03-30 Rca Corp Modulation
US2103847A (en) * 1928-10-02 1937-12-28 Rca Corp Signaling
US2266401A (en) * 1937-06-18 1941-12-16 Int Standard Electric Corp Signaling system
US2271721A (en) * 1939-05-03 1942-02-03 Rca Corp Method and means for transmitting a plurality of signals over the same channel
US2326584A (en) * 1939-02-20 1943-08-10 Hartford Nat Bank & Trust Co Multiplex telephony system
US2395467A (en) * 1943-10-19 1946-02-26 Standard Telephones Cables Ltd Multiplex telephone system
US2416286A (en) * 1942-10-07 1947-02-25 Standard Telephones Cables Ltd Signal transmission system
US2416328A (en) * 1942-07-03 1947-02-25 Standard Telephones Cables Ltd Radio receiver

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2103847A (en) * 1928-10-02 1937-12-28 Rca Corp Signaling
US2075071A (en) * 1932-07-23 1937-03-30 Rca Corp Modulation
US2045107A (en) * 1932-12-02 1936-06-23 Rca Corp Phase modulation
US2266401A (en) * 1937-06-18 1941-12-16 Int Standard Electric Corp Signaling system
US2326584A (en) * 1939-02-20 1943-08-10 Hartford Nat Bank & Trust Co Multiplex telephony system
US2271721A (en) * 1939-05-03 1942-02-03 Rca Corp Method and means for transmitting a plurality of signals over the same channel
US2416328A (en) * 1942-07-03 1947-02-25 Standard Telephones Cables Ltd Radio receiver
US2416286A (en) * 1942-10-07 1947-02-25 Standard Telephones Cables Ltd Signal transmission system
US2395467A (en) * 1943-10-19 1946-02-26 Standard Telephones Cables Ltd Multiplex telephone system

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2583484A (en) * 1945-12-15 1952-01-22 Radio Patents Corp Combined angular velocity and pulse modulation system
US2611826A (en) * 1947-06-05 1952-09-23 Kalfaian Meguer Simultaneous amplitude modulation and phase modulation with economy in bandwidth
US2680153A (en) * 1949-01-14 1954-06-01 Philco Corp Multichannel communication system
US2662116A (en) * 1949-12-31 1953-12-08 Potier Gaston Xavier-Noel Double modulated pulse transmission
US2716217A (en) * 1950-07-29 1955-08-23 Raytheon Mfg Co Communication system
US2824908A (en) * 1952-08-07 1958-02-25 Du Mont Allen B Lab Inc Television system method and apparatus for multiplex signaling
US3020349A (en) * 1954-12-03 1962-02-06 Int Standard Electric Corp Electric pulse modulating and demodulating circuits
US2918665A (en) * 1955-04-08 1959-12-22 Gilfillan Bros Inc Modulation method and system
US2953644A (en) * 1956-10-04 1960-09-20 Bell Telephone Labor Inc Wave transmission system
DE1117643B (de) * 1958-08-06 1961-11-23 Siemens Ag Schaltungsanordnung zur multiplikativen Mischung zweier elektrischer Signale
US3078449A (en) * 1958-09-24 1963-02-19 Cons Electrodynamics Corp Commutating and modulating apparatus
US3167614A (en) * 1959-03-16 1965-01-26 Rca Corp Multiplicative stereophonic sound signalling system
US3286521A (en) * 1964-03-26 1966-11-22 Kennecott Copper Corp Wind direction and velocity recording system

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GB596051A (en) 1947-12-24

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