Siemens Aktiengesellschaft

Wilhelm Volejnik

Gerhard Musil

Hermann Betzl

Guenter Weimert

Friedrich L Kuenemund

Johann Magerl

Karl Traub

Walter Lechler

Werner Pokorny

Albrecht Grabner

Franz Fuerlinger

Walter Steiner

Udo Fiedler

Hans Albsmeier

Method and arrangement for transmitting digital signals

Process and device for timing recovery

Method for inputting signals into and outputting signals out from

A method and apparatus for recovering the clock and/or the clock phase of a synchronous or plesiochronic digital signal provide that logic circuits in gate arrays or cell arrays recover the clock. In an auxiliary clock generator, an auxiliary clock is generated, or auxiliary clocks of the same frequency and different phase relationship extracted therefrom are generated which, conducted by way of a phase correction facility, provide an auxiliary data clock as the recovered clock. In principle, the frequency of the auxiliary clock or auxiliary clocks deviates from that of the auxiliary data clock to be formed. A phase sensor checks whether the active edges of the digital signal and of the auxiliary data clock have approached each other to less than a predetermined time interval and emits a corrections signal as soon as such an event occurs. This signal causes a phase shifting of the auxiliary data clock by switching between the extracted auxiliary clocks and/or by reversing the polarity of the auxiliary clock or of the extracted plurality of auxiliary clocks.

Method and apparatus for extracting an auxiliary data clock from the

In a switching location for TDM multiplexing of a combination of a plurality of channels for digital signals to form a common channel in one transmission direction and for demultiplexing a common transmission channel into a plurality of channels in the opposite transmission direction, the signals of the individual communications channels are combined to form pulse messages each of which is preceeded by a frame identifier word monitored by a monitoring memory with respect to its bit sequence and with respect to its periodicity. Double monitoring devices and one's density monitoring devices are provided for the input signals arriving via the individual communications channels. Potentially, code converter monitoring devices for the input and output signals are provided. A stepping bit monitoring device is provided for the input signals arriving via the individual communications channels. A level monitoring device is provided for the input signals arriving via the common communications channel. A frame clock monitoring device is provided for the common incoming transmission channel. A synchronism of the receiving device is monitored for the demultiplexer. Bit error monitoring is provided for the input signal of the demultiplexer. Frequency monitoring devices and level monitoring devices are provided for the output signals for the individual communications channels departing the apparatus.

Monitoring means for digital signal multiplex equipment

The invention relates to an electrical filter circuit operated with a definite sampling and clock frequency f.sub.T, such filter being made up of CTD elements, and having at least one bipolar or quadripolar resonator in the form of a self-contained conductor loop (for example, C.sub.1, C.sub.2) with unidirectional transmission behavior. Differences in the transfer capacitances of such circuits are reduced, as far as possible, in order to thereby simplify integrated manufacture as far as possible, by positioning the frequency band to be filtered out at a frequency position which lies above half the clock frequency (f.sub.T /2), or in the range from f.sub.T /2 through 3f.sub.T /2.

Electrical filter circuit operated with a definite sampling and clock

A carrier frequency communication transmission system has a premodulation band above the transmission position of the base primary group of 60-108 kHz and utilizes mechanical filters as channel filters and also a common group filter in order to filter out the primary group band. Bending resonators having longitudinal coupling are utilized as the mechanical filters. The frequency range of the premodulation band at its lower limit is determined by a frequency spacing of at least 4 kHz from the upper band limit of the primary group band and the upper limit of the frequency range is determined in that the interfering natural oscillations, inasmuch as they occur in the lower stop band of the channel filter, lie at least 12 kHz below the lower limit of the primary group band. Highly stabilized piezo ceramics is used as the electromechanical transducer material.

Carrier frequency communication transmission system having premodulation

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Sauerlach, Germany

Wilhelm Volejnik