JPS5822895B2 - Method of input/output coupling of broadband pulse signals to remote power supply cable section - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for coupling broadband pulse signals into and out of a cable section with intermediate amplification points which are supplied remotely via transmitting and receiving high-voltage capacitor arrangements.

In order to transmit broadband pulse signals from one end station to another over a long distance over a cable section, it is necessary to insert intermediate amplification points at predetermined intervals in the cable section.

During the transmission of pulses, these amplification points, which also include regenerative repeaters, require a certain operating power which is supplied via the inner conductor of the coaxial cable.

Since the intermediate amplification points are connected in series with respect to the supply current flowing through the cable, in long cable sections remote supply potentials of more than 100 μ can occur at the supply point of the cable section.

Since the feed points are at the respective ends of the cable section, there is the problem of coupling the broadband pulse signal to be transmitted into the cable section at a high potential and/or coupling it out at the end of this cable section.

Input/output coupling of pulse signals to remote power supply cable section,
It is known to perform this by means of high-voltage capacitor arrangements arranged on the transmitting and receiving sides.

Such a device is described, for example, in German Patent Application No. 1919110.

The advancement of transmission technology towards higher frequencies creates difficulties in particular in the transmission of high-speed time-division multiplexed signals.

This is because in this case, a very wide frequency band is required for distortion-free transmission of transmission pulses.

A distortion-free coupling of the pulses into and out of the cable section is of particular importance with regard to the equalizers arranged at the respective receiving end.

These respective equalizers arranged at the input of the intermediate regenerator or intermediate amplifier have equalization characteristics adapted to the transmission characteristics of the cable used.

Therefore, for additional equalization of the input and output coupling distortions, intermediate regenerators or intermediate amplifiers adjacent to the coupling locations must contain further equalizers, as long as equalization is possible at these locations in the first place. No.

This results in additional costs, in particular with regard to the necessary interchangeability of intermediate regenerators, and possibly also the distance between the incoming coupling position and the next intermediate regenerator than the usual one used for this section. It shall be decreased by increments with respect to regenerative repeater spacing.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to find a method for coupling broadband pulse signals into and out of a remote supply cable section without distortion.

According to the present invention, this problem is solved as follows.

That is, the precoded signal is transmitted via a high-voltage capacitor device on the transmitting side, regenerated and amplified at a high potential by the clock signal transmitted together to generate a quasi-3 signal, and on the receiving side from the cable section. The transmitted signal is equalized at a high potential and regenerated by a clock signal, its spectrum is transformed so that the DC component and low frequency component are largely suppressed, and the newly transformed signal is received after this transmission. via a side high-voltage capacitor device to a device at a lower potential, where this transmitted signal is regenerated once more,
Then perform the inverse transformation.

A particular advantage of this method is that it is easy to implement.

This is because methods for modifying the spectrum of broadband pulse signals are known.

Furthermore, due to the potential separation position, the method according to the invention does not simultaneously introduce significant noise and linear distortion in the subsequent equalizing amplifier, so that a simple regeneration of the transmitted pulse signal is possible.

The method of the invention therefore eliminates the need for high-voltage resistant isolation locations at the output terminals of the transmitting line end device and at the input terminals of the receiving line end device, which would create undesirable linear distortions of the signal.

These distortions disadvantageously add to the noise in the equalizing amplifiers following each of these separation locations and unacceptably degrade the signal-to-noise ratio.

By introducing a high-voltage resistant isolation location into the line end equipment at a location where the signal is regenerated and therefore free of noise, only linear distortions are added to the signal, and these distortions are only as good as the signal-to-noise ratio allows. It will not cause any deterioration that cannot be done.

A particularly advantageous embodiment of realizing pulse regeneration is obtained as follows.

That is, the reproduction of the pseudo-3 communication signal is performed by converting it into an amplitude-regenerated 2-communication signal, time reproduction of the 2-communication signal, and subsequent inverse conversion to the pseudo-3 communication signal.

The bit clock signal required for reproduction is transferred via an additional high-voltage capacitor in such a way that the bit clock signal is transmitted via a potential separation point.

Embodiments of an apparatus for carrying out the method of the present invention will be described below with reference to the drawings.

The transmitting end station shown in FIG.
A time-division multiplexed signal with a bandwidth of seconds is received, optionally further randomized using a scrambler, and present at 2 brigadiers.

This signal is used by EXOR, which operates as a modulo-2 adder.
It is added bit by bit to a second signal in gate mod1, which second signal is generated from the output signal of EXOR gate mod1 by being delayed by a bit period in D flip-flop T1.

The modification of the input signal is thereby carried out in a precoding-like manner, with each pulse in the input signal occurring as a level change in the precoded signal.

This precoding prevents erroneous transmission caused by interfering signals, and at the same time provides a desired AMI code in the transmission interval along with conversion to a pseudo-triple signal, which will be described below.

A signal processing device S1 is arranged in the signal path at the connection to the summing stage mod1.

In addition to the amplification stage, the device also includes a pulse shaping stage.

A signal is supplied from the output terminal of the signal processing device S1 to one terminal of a stub wire L1 whose ends are short-circuited, and is further supplied to a high-voltage capacitor C1, and the other terminal of this stub wire is connected to ground. .

The second wave is generated by reflection of the binary pulse at the end of the stub wire
A pulse occurs, which has the opposite polarity to the initial pulse.

Since the length of the line L1 is determined so that the amount of delay of this second pulse corresponds to the bit interval of the transmission signal, pseudo-three signals are generated overall.

This pseudo-3 signal is supplied via a capacitor C1 to one input terminal of a transmission output stage SE, which furthermore has a clock input terminal and a terminal for remote power supply.

In the embodiment shown in FIG. 1, the bit clock is supplied from the clock input terminal 2 of the terminal station, the clock processing device TI.
' and a second high-voltage capacitor C2.

Furthermore, a terminal of a stub line L2 whose ends are similarly short-circuited is connected to the output terminal of the clock processing device Tl/, and the other terminal of this stub line is grounded.

Line L2 is used for protection against overvoltage.

The length of this line is selected so that it forms a λ/4 line with respect to the clock frequency.

The transmit output stage includes a regenerator for the transmitted quasi-ternary signal, which is converted into an amplitude-regenerated binary signal.

After another time recovery, a binary signal is obtained, which is supplied to one terminal of the third stub line L3 and the cable section at the remote supply potential.

The reflection on the third stub line L3 then again produces a pseudo-3 signal, which is used as a section signal and is present in the AMI code in this case.

The remote supply potential is AC coupled to the low potential via C3.

The receiving end station shown in FIG. 2 receives the distorted pseudo-3 signal from the cable via the input terminal 5, and thus in this case the distorted AMI signal.

One terminal of a fourth stub line L4 is connected to this input terminal 5, and the other terminal of this stub line is connected to a point at AC ground potential of the equalization and discrimination device E'S. has been done.

Line L4 is also used for overvoltage protection.

The signal input terminal of the equalization and discrimination device ES is connected to the stub line L.
4 receives the output signal of the modified cable section.

This signal is equalized with respect to the frequency characteristics of the cable and line L4 used by an equalizer connected to the input terminal of the device BS and, after conversion into a binary signal, reproduced in time and of the device ES. available at output terminal 6.

The device ES generates a suitable bit clock for the reproduction of the binary signal, which bit clock is further supplied to the output terminal 7.
Furthermore, the device ES is connected via a terminal 8 to a remote power supply.

The remote supply potential is AC coupled to the low potential via C4.

The binary signal reaches one terminal of the high-voltage capacitor C5 from the output terminal 6 and also one terminal of a further stub wire L5, the other terminal of which is connected to the device at alternating current ground potential. Connected to the ES point.

The reflection of the binary signal on the stub line L5 produces a quasi-ternary signal, which signal is fed via the capacitor C5 to the signal input terminal of the second signal processing device S2.

For signal preparation, the device S2 receives the clock output from terminal 1 of the equalization and discrimination device ES and transferred via a capacitor C6.

Line L6 is used for protection against overvoltage.

The length of the line L6 is determined so that it forms a λ/4 line with respect to the clock frequency.

Device S2, like stub line L6, is not at a remote power supply potential, but at a very low potential.

After clocking of the pseudo-ternary signal and its inverse conversion into an amplitude-recovered binary signal, a time recovery of this binary signal takes place, which signal is available at the output terminal 9 of the device S2.

Furthermore, the device S2 has a clock output 6 at which the pit clock of the transmitted signal is available for controlling subsequent devices in the signal path.

Via a second EXOR gate mod2 connected to terminal 9 and used as a modulo-2 adder, decoding is performed to cancel the precoding on the transmitter side, this EXOR gate also adding a second delay. It receives an output signal delayed by the bit width via device T2.

The transmitted signal then appears again in binary form at the output terminal 10, which is connected to the output terminal of the EXOR gate mod2, for further signal processing.

The stub wire converting the 2-signal into the quasi-3-signal was chosen in this case instead of the choke placed in the signal path because of its much better protection against pulsed overvoltages and therefore against lightning voltages.

However, there are additionally added surge arrester diodes in the signal box to bypass overvoltages, and in some cases additional stub wires.

[Brief explanation of drawings]

FIG. 1 shows P with a bit rate of 565 Mbit/s.
FIG. 2 is a diagram showing a CM system transmitting side terminal station, and FIG. 2 is a diagram of a receiving side terminal station. mod 1, mod 2...EXOR
Gate, 81°S2...Signal processing device, S
E...Transmission output stage, ES...Equalization and discrimination device, T1'...Clock processing device, L
l, L2. L3. L4...L5゜L6...
...Stub line.

Claims (1)

[Claims] 1. Precoding of the input signal at the transmitting end and transmission of the input signal at the receiving end via a high-voltage capacitor arrangement on the transmitting side and a high-voltage capacitor arrangement on the receiving side at both ends of the cable section with remotely powered intermediate amplification points. and the corresponding inverse transformation of
During precoding, each n 1 in the input signal
Coupling of broadband pulse signals into and out of a remote feeder cable section in which the n pulses occur as level changes in the precoded signal and the precoding and inverse conversion is performed at low potentials. In the method, the precoded signal is transmitted through a transmitting high-voltage capacitor device, and is regenerated and amplified at a high potential using a clock signal transmitted in a compressed manner to generate a pseudo-ternary signal; On the receiving side, the signal sent from the cable section is equalized with a high potential and regenerated using a clock signal, and its spectrum is transformed so that the DC component and low frequency component are greatly suppressed, and the signal is newly transformed. A remote power supply cable section characterized in that the transmitted signal is fed via a receiving high-voltage capacitor arrangement to a device at a low potential, where this transmitted signal is regenerated once more and subsequently converted back. A method for input/output coupling of broadband pulse signals.