Method and apparatus for transmitting coded information

Process for the simultaneous transmission of first information from a first to a second station and of second information from the second to the first station over a single transmission path, comprising the following steps:

• carrying out the following steps in said first station:
• (a) producing an essentially sinusoidal first signal having a predetermined frequency as well as a predetermined phase and consists of a sequence of oscillation periods each of which at any given time contains two half-waves following one another with predetermined duration and opposite polarity, wherein said half-waves are able to take on at least two different discrete amplitude values which set forth a code representing said first information, and wherein all amplitude values are greater than zero, (b) transmitting said first signal from said first station to said second station over said single transmission path,
• carrying out the following steps in said second station:
• (a) obtaining a second sinusoidal oscillation having said predetermined frequency and phase by a resistance-arrangement adapted to apportion the transmitted first signal, (b) decoding the transmitted first signal in order to retrieve said first information, (c) feeding said second sinusoidal oscillation as an input signal into a 90-degree-phase shifter, which delivers an output signal, phase shifted by 90 degrees with respect to said input signal and thus shifting the phase of said second sinusoidal oscillation by 90 degrees, (d) producing an essentially sinusoidal second signal out of the phase-shifted second oscillation, wherein said second signal has the phase of the phase-shifted second oscillation and the predetermined frequency and consists of a sequence of oscillation-periods, each of which at any given time contains two half-waves following on each other with predetermined duration and opposite polarities, wherein said half-waves are able to take on at least two different discrete amplitudes, which set forth a code representing said second information, and wherein all amplitude values are greater than zero, (e) transmitting said second signal over said single transmission path to said first station, and
• carrying out the following step in said first station:
• decoding the transmitted second signal in order to retrieve said second information.

Process for the transmission of information from several subscribers over an appropriate connection to a transfer system, comprising the following steps:

• (a) translating information which is to be transmitted form one predetermined subscriber on the transfer system into a coded alternating current signal in which at least one of two half-waves of each period forms a code element of a code setting forth said information, (b) translating information which is to be transmitted from the transfer system to a predetermined subscriber into a coded alternating current signal in which at least one of two half-waves of each period forms a code element of a code setting forth said information, (c) synchronizing the coded alternating current signal from one subscriber and the coded alternating current signal from the transfer system so that said signals have a relative phase displacement of 90 degrees by passing the coded alternating current signal from one subscriber or the coded alternating current signal from the transfer system through a phase shifter, (d) selectively receiving the coded alternating current signal transmitted from the transfer system to the subscriber at the location of the subscriber, (e) decoding the coded alternating current signal transmitted from the transfer system to a predetermined subscriber and at the location of this subscriber, (f) selectively receiving the coded alternating current signal transmitted from the subscriber to the transfer system at the location of the transfer system, and (g) decoding the coded alternating current signal transmitted from the subscriber to the transfer system.

Process for the coded transmission of several information signals via a common transmission path in which

• each information signal is transformed into a code alternating current of a predetermined frequency, wherein the code alternating currents contain code elements which consist of at least one half wave of the code alternating current;
• two code alternating currents are added with a mutual phase shift of 90.degree., in order to produce a sum alternating current with a predetermined phase state;
• the sum alternating current is combined with a further coded alternating current, which is shifted in phase by 90.degree. with respect to that of the sum alternating current;
• and the combined coded alternating current is transmitted;
• wherein the production of a code alternating current includes the following steps:
• (a) producing a clocksignal with a period which is equal to the duration of a predetermined incremental change in the half-wave duration, (b) applying the clock-signal to a counter with controllable start-time and counting the clock-signal by means of the counter, (c) selectively sampling output signals from the counter to selectively determine the duration of the running half-wave of the alternating current, (d) applying the sampled output signals to a bi-stable switch-means which delivers a square-wave signal having axis crossings corresponding to the arrival of successive sampled signals from the counter and half-cycle durations determined in accordance with the selection of the sampling signals, (e) resetting the counter by the counter-output signal, (f) controlling the amplitude of the half-waves of the square-wave signal depending upon the information to be transmitted, and (g) transforming the square-wave voltage produced from the switch means into a sinusoidal signal.

Process for the coded transmission of a color-TV signal, which contains a luminance component, first and second color components and additional signal components, comprising the following steps:

• (a) producing a first code alternating current which has a predetermined frequency and consists of a sequence of oscillation periods which contain at any given time two half-waves of opposite polarity, (b) producing a second code alternating current which has the predetermined frequency and consists of a sequence of oscillation periods which contain at any given time two half-waves of opposite polarity, wherein the amplitudes of the half-waves of said first and second code alternating currents represent the luminance component, (c) producing a third code alternating current which has the predetermined frequency and consists of a sequence of periods which at any given time contain two half-waves of opposite polarity, wherein the half-waves of the third code alternating current are capable of taking on at least two discrete, differing amplitude values which form a digital code which represents at least the first color signal component, (d) producing a fourth code alternating current which has the predetermined frequency and consists of periods which at any given time contain two half-waves of opposite polarity which form a digital code which represents at least the second color component, (e) adding the first and second code alternating currents with a mutual phase shift of 90 degrees in order to produce a first sum code alternating current, (f) adding said third and fourth code alternating currents with a mutual phase shift of 90 degrees in order to produce a second sum alternating current, (g) adding the first and second sum code alternating currents with a mutual phase shift of 90 degrees in order to produce a combined code alternating current, and (h) transmitting the combined code alternating current.

Process for the coded transmission of several information signals via a common transmission path in which

• each information signal is transformed into a code alternating current of a predetermined frequency, wherein the code alternating currents contain code elements which consist of at least one half wave of the code alternating current;
• two code alternating currents are added with a mutual phase shift of 90.degree., in order to produce a sum alternating current with a predetermined phase state;
• the sum alternating current is combined with a further coded alternating current, which is shifted in phase by 90.degree. with respect to that of the sum alternating current;
• and the combined coded alternating current is transmitted;
• wherein the code elements which are formed by half-waves of a predetermined first polarity of a first of said alternating currents represent a first stereo-signal and the code elements which are formed by half-waves of a second polarity of said first alternating current opposed to the first polarity represent a second stereosignal.

Process for the simultaneous transmission of first information from a first to a second station and of second information from the second to the first station over a single transmission path, comprising the following steps:

• carrying out the following steps in said first station:
• (a) producing an essentially sinusoidal first signal having a predetermined frequency as well as a predetermined phase and consists of a sequence of oscillation periods each of which at any given time contains two half-waves following one another with predetermined duration and opposite polarity, wherein said half-waves are able to take on at least two different discrete amplitude values which set forth a code representing said first information, and wherein all amplitude values are greater than zero, (b) transmitting said first signal from said first station to said second station over said single transmission path,
• carrying out the following steps in said second station:
• (a) obtaining a second sinusoidal oscillation having said predetermined frequency and phase by passing the transmitted first signal through a fork circuit, (termination circuit) (b) decoding the transmitted first signal in order to retrieve said first information, (c) feeding said second sinusoidal oscillation as an input signal into a 90-degree-phase shifter, which delivers an output signal, phase shifted by 90 degrees with respect to said input signal and thus shifting the phase of said second sinusoidal oscillation by 90 degrees, (d) producing an essentially sinusoidal second signal out of the phase-shifted second oscillation, wherein said second signal has the phase of the phase-shifted second oscillation and the predetermined frequency and consists of a sequence of oscillation-periods, each of which at any given time contains two halfwaves following on each other with predetermined duration and opposite polarities, wherein said half-waves are able to take on at least two different discrete amplitudes, which set forth a code representing said second information, and wherein all amplitude values are greater than zero, (e) transmitting said second signal over said single transmission path to said first station, and
• carrying out the following step in said first station:
• decoding the transmitted second signal in order to retrieve said second information.