Single channel communication system

• US 3,866,230 A
• Filed: 03/02/1973
• Issued: 02/11/1975
• Est. Priority Date: 03/02/1973
• Status: Expired due to Term

• Current Assignee: John M. Tewksbury
• Original Assignee: John M. Tewksbury
• Inventors: Tewksbury, John M.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Bookbinder, Marc E.
• Application Number:
  US05/337,520
• Time in Patent Office: 711 Days
• Field of Search: 178/68,69.5R,58R 179/15BS 325/15-17,58 343/175,178,179 340/147SY
• US Class Current: 370/280
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions

Abstract

In a single channel communication system which includes cooperating stations, each station transmits a train of pulses, each cycle of these pulses transmitted from a local station being modified by pulses received from another cooperating station to reduce or increase the local pulse period as needed to produce identical periods at each station and also to transmit pulses from the local station during the time between received pulses. An equilibrium condition is established in which the departure from synchronization of transmitted and received pulses in each station is proportional to its need for control. Intelligent modulation of the pulse period at any station is then evident and may be recovered at each station.

Claims

1. A station adapted for use in a common channel communication system, said system including at least one remote means for transmitting modulated pulses, said station comprising:

means for receiving the pulses from said remote means;

means responsive to the received pulses for generating individual pulses of a pulse train in the interval between received pulses and for modulating the pulse train to include the modulation of the received pulses;

means for transmitting the modulated pulse train;

wherein said means for generating and for modulating includes;

a timing network of the relaxation type for generating the individual pulses in said pulse train; and

, means for continuously altering the time constant of said network in response to at least the received pulses.

2. A station as claimed in claim 1 wherein said means for generating and for modulating includes means for determining the difference between the time of occurrence at said station of a pulse transmitted from said station and an adjacent pulse received by said station.

3. A single channel communication system including first and second stations, each having a receiver for receiving pulses transmitted from the other station and a transmitter for transmitting a pulse train linking the transmitter to said channel, and wherein intelligence signals local at each station respectively are to be communicated over the system, each station comprising:

an oscillator including an active device and a variable rate charging circuit, the period of said oscillator depending upon the rate of charge of said charging circuit;

means for varying the rate of charge of said charging circuit in accordance with the local intelligence signal of the station;

keying means for said transmitter controlled by the output of said oscillator whereby said transmitter is keyed to transmit a pulse;

means for shaping the transmitted pulses to conserve bandwidth in the channel;

syncHronizing means for establishing substantial synchronization between the pulses transmitted and received at each of said stations, said synchronizing means further altering the rate of charge in said charging circuit during the occurrence of a received pulse and wherein said synchronizing means comprises;

means responsive to a pulse transmitted from a local station for generating a timing mark a predetermined time after the pulse is transmitted and generally centrally located between adjacent transmitted pulses; and

means for generating a signal related to the departure of a received signal from said timing mark, said signal being applied from said synchronizing means to alter the rate of charge from said charging circuit.