Abstract: To protect a semiconductor switch from high forward blocking voltage stresses during turn-off, a relief circuit is provided comprising a diode and a capacitor. The energy generated when the semiconductor switch is turned off or switched to the non-conducting state, is temporarily stored in the capacitor of the relief circuit until the semiconductor switch is changed back to its conducting state. Then the energy stored in the capacitor is transferred to a useful impedance by means of a further semiconductor switch being changed to its conducting state.

Abstract: A method and apparatus for correcting errors in convolutional code signals prior to Viterbi decoding. Branch metrics in the decoding of n-PSK convolution code signals are used to obtain a differential metric with calculations in both the logical and arithmetic domain. The differential metric is used to obtain a phase error signal which includes information on the quality of the convolution code signals, and control signals for the resolution of phase ambiguity in the demodulation of the convolution code signals are obtained using the phase error signal, such that an improvement in the bit error rate and synchronization is made possible, in particular in decoders for error-correctable convolution code signals. The phase error signal is produced when, over a predetermined time period the differential metric is less than a given threshold value or is decreasing, so as to indicate an error in the demodulated convolution signal over such time period and therefore the probable presence of a phase error.

Abstract: Digital transmission arrangement operating with coded scanning samples and whose transfer function can be changed without interrupting operation and with low interference starting from an initial transfer function to a final transfer function, the arrangement including a switching device for the transmission coefficients to be associated with each transmission member of the transmission arrangement for switching from a set of starting coefficients to a set of final coefficients, the switching device being configured to switch in a single set of intermediate coefficients (c.sub.0) between the set of starting coefficients (c-) and the set of final coefficients (c+), and the set of intermediate coefficients (c.sub.0) being determined, as a function of the set of starting coefficients (c-) and the set of final coefficients (c+), so that he interference to be expected during switching is minimized.

Abstract: Method and apparatus for processing compressed, stored analog signals, such as audio signals, from a storage medium, including first converting the signals to digital signals and thereafter expanding the signals.To realize a large volume range in the conversion of compressed recorded signals to expand digital signals, the compressed analog signals picked up from a storage medium are initially analog/digital converted and only then digitally expanded.

Abstract: Comb-like cable guide elements are provided for each row or pair of rows of cable ends disposed at a distance from a plug-in contact plate for the orderly guidance of the cable ends to plug-in contacts of a plug-in contact plate. Free spaces are provided between adjacent cable guide elements for insertion of circuit boards toward contact strips disposed on the plug-in contact plate. To absorb the pull on the cable ends, resilient clamping devices are provided in the region of recesses in the cable guide elements.

Abstract: A method of detecting edge structures in a video signal, with a decision criterion being derived from the environment pixels of an image pixel so as to realize image coding with the least number of bits possible. The object of detecting all of the oblique edges i.e. edges which are not horizontal or vertical, is accomplished in that an average is formed from the environment pixels of an image pixel and this average is then compared with each environment pixel so as to obtain an output signal having one of three-values (1, 0, -1) dependiing on whether the luminance or chrominance values of the particular environment pixel is above, within or below a given tolerance range. A conclusion as to the existence of an edge and its orientation is then drawn from the number of immediately consecutive identical positive or negative values (1 or -1) of this possible three-valued signal for an image pixel and from the position of the changes in value within the sequence of environment pixels.

Abstract: The present invention relates to a multicarrier demodulator for separating and demodulating a digitalized frequency multiplexed signal into a plurality (L) of individual channel signals, with the separation being performed using a frequency division demultiplexer (FDM). The separated channel signals are each filtered using bandwidth limitation filters and thereafter demodulated using a synchronous demodulator. Following demodulation, the signals are filtered by interpolation filters, data (Nyquist) filters, and subsequently decided upon in a decider. The invention is characterized by the fact that the demodulator operates upon a pair of phase displaced complex channel signals.

Abstract: A method for compensating for shifts in delay caused by the Doppler effect in the bursts from ground stations when received by a transponder satellite, wherein a search is made within the bursts for agreed-upon bit patterns. Then a phase comparison is made between the system clock pulse of the satellite and the clock pulse recovered from the bursts, with the point in time of this phase comparison being derived from the finding of the bit pattern. Depending on the result of the phase comparison, the burst are now delayed to a greater or lesser extent.

Abstract: A method of deriving the word timing or word boundaries of a PPM signal, without requiring a synchronizing marker to be added to the PPM signal, employs a bipolar evaluation signal which begins at any time slot of the PPM signal. The evaluation signal is multiplied repeatedly with successive portions of the PPM signal within a time frame of the PPM signal which extends over a plurality of word lengths, and the product signals are integrated. Such repeated multiplications with subsequent integration are performed a number of times, with the evaluation signal being offset by one time slot each time. The time position of the evaluation signal which, after repeated multiplication and integration, produces the smallest possible signal, is considered to be in phase synchronism with the word timing of the PPM signal.

Abstract: A device for attaching a splice protector to a splice provided between two conductors includes a base; a receiver mounted on the base for receiving the splice protector in an open state thereof; two backup members situated at each end of the receiver for supporting the two conductors while the splice extends between the splice protector positioned in the receiver. The backup members are movable in a direction perpendicular to their conductor-supporting faces. Pressing jaws, which are mounted on at least one of the backup members, are disposed bilaterally of the receiver. At least one of the pressing jaws is pivotally attached to the backup member for a pivotal motion towards and away from the other pressing jaw.

Abstract: The present invention relates to a three-stage coupling arrangement for an electrical data exchange system in which coupling matrixes of all stages are constructed identically. The coupling matrixes are divided among two switchboards. The number of inputs of a coupling matrix is equal to the number of its outputs and the inputs and outputs of the first switchboard are connected with the identically numbered inputs and outputs, respectively, of the second switchboard.

Abstract: Reliable phase synchronicity between a local carrier signal and the carrier signal of an amplitude and/or phase shift keyed received signal is produced as quickly as possible by employing a phase detector characteristic whose root means square outside of the synchronization point is as large as possible and whose synchronization point, i.e., zero passage, is situated such that it also considers a phase deviation of the received signal component from its quadrature position.

Abstract: To regulate a single sideband up converter having a pair of mixer stages (M1, M2), each mixer stage receives control signals to compensate for spurious signals of the mixer components. Part of the radio frequency output signal (RF') from the converter is fed to a down converter (M3). From the resulting down-converted signal, the original intermediate frequency signal (IF) as well as the first harmonic thereof are filtered out as a measure of oscillator and sideband suppression. From these filtered-out signals, control signals for the mixer stages (M1, M2) are obtained.

Abstract: A method and circuit arrangement for synchronizing a receiver in a digital transmission system with transmission of a special preamble selected in such a manner that, with correct demodulation, the received signal has a cosine shape with a pattern frequency fp from which the clock pulse frequency results, and wherein frequency and/or phase of the carrier and clock pulse signal, respectively, are estimated, and, after demodulation with an assumed carrier frequency ft0, the individual spectral lines (gp, gn) of the received signal (rd) are obtained by filtering, and from these signals, their frequency (fgp, fgn) and phase ( gp, gn) are determined by linear regression, with these frequency and phase values being used, by means of subsequent difference and sum formation, to obtain the following estimated values: ##EQU1##

Abstract: A method of obtaining a signal representing the phase difference between a local carrier signal and the carrier of an amplitude and/or phase shift keyed received signal wherein: the received signal is divided into two cartesian coordinate signal components which are a function of the phase difference and are in a quadrature relationship to one another; each pair of cartesian coordinate signal components, each representing one of a plurality of permitted signal states, is converted into two corresponding polar coordinate signal components, a decision is then made as to which is the permitted, unfalsified polar signal components which the polar signal components of the received signal most closely approach; and the phase difference is derived from a comparison between the decided-upon polar signal components and the received polar signal components.

Abstract: The invention relates to a digital filter tree composed of a plurality of digital filter banks arranged in a tree structure one behind the other to branch out in stages with a separation into L.sub..nu. individual signals taking place in each stage and the sampling rate being reduced each time by the factor M.sub..nu. where .nu.=1,2, . . . identifies the .nu.th stage. The filter tree employs a prototype filter with half-band functions for channel center frequencies f.sub.l =l.multidot.B+B/2, with a real frequency multiplex input signal being separated into L.sub..nu. complex channel signals for further processing by means of a discrete Fourier transformation. For all stages M.sub..nu. =2 and L.sub..nu. =4 are fixed, with only two signals of the L.sub..nu. =4 being utilized.

Abstract: A phase shifter suitable for operation at very high high-frequency power is composed of a waveguide in which ferromagnetic material is distributed along at least one plane extending in the direction of wave propagation. The ferromagnetic material is exposed to a static magnetic field oriented parallel to the plane. The ferromagnetic material is shaped so that it forms a plurality of three-dimensional regions which extend in the direction of the applied static magnetic field from one waveguide wall to the opposite waveguide wall. These regions may be provided by a plurality of ferromagnetic rods, preferably housed in one or more dielectric containers to direct a flow of coolant fluid, or by a ferromagnetic body having a plurality of bores. Such bores also preferably direct a flow of coolant fluid.

Abstract: An abrasion device for removing a primary protective coating from an optical waveguide workpiece. The device includes two abrasive wheels each having an abrasive circumferential surface. The wheels are arranged axially parallel with their circumferential surfaces beside one another and are mounted for rotation in opposite directions relative to each other. The wheels are positioned on opposite sides of a region in which the workpiece is disposed to cause the primary protective coating ground off by tangential contact with the circumferential surface of each wheel as the wheels are rotated.

Abstract: A circuit arrangement for switching PCM channels conducting baseband data signals, with serial data to be switched arriving at n input ports and being converted in blocks to parallel form, intermediately stored in a memory and converted to serial form again after read-out to be fed to n output ports each assigned to one or a plurality of destination addresses. The parallel data blocks are intermediately stored the first time in n input registers assigned to the n input ports. Thereafter, a second intermediate storage takes place in a RAM memory in such a manner that the data blocks are written in successively according to the sequence in which they arrived at a memory address which is counted up sequentially, or the data are subsequently intermediately stored in a RAM memory at a memory address which corresponds to the respective destination address.

Abstract: A junction circulator suitable for high power, high-frequency use has a microwave junction zone which is penetrated by a static magnetic field. Disposed in the microwave junction zone is a ferromagnetic resonator composed of different dielectric media, at least one of which has ferromagnetic characteristics. The interfaces between the various dielectric media form three-dimensional bodies which extend over the entire height of the junction zone and which have cross sections that do not change in the direction of the static magnetic field. These interfaces may be provided by parallel ferrite rods, or a ferrite body with parallel bores.