Abstract: Image data representing successive original images is prepared for transmission by comparing the characteristics of an image data portion associated with each image region of each original image with the characteristic of the image data portion of the same image region of the immediately preceding original image to produce an indication of any difference between the image portions with respect to the characteristic, each differences indication is compared with a threshold value representing a selected difference indication, and, based on each difference indication which exceeds the threshold value, an operation is performed, which involves preparing transformation-coded data or determining a motion vector. The Threshold value from one original image to the next is changed so that the threshold value has a low value for a first group of original images and a high value for a second group of original images, where the original images of the first group alternate with the original images of the second group.

Abstract: Method of preparing data, in particular voice signal parameters for transmission at a low bit rate, identical signal parameters are combined interval by interval in quantized form; forfurther bit reduction, bits are suppressed from the total number of bits of at least two intervals, the bit difference to be suppressed being formed on the basis of the total number of unreduced bits with respect to the next-higher power of two; and theprocedure supplies a better voice quality than in the case of changing the number of quantization stages by multiples of 2.

Abstract: The vector encoding method, particularly for voice signals, includes storing autocorrelation coefficients in one codebook and performing a logic operation on the autocorrelation coefficients with an autocorrelation function for the pulse response of an excitation filter to give the energy of the filtered excitation signal. For additional data reduction only those values having three autocorrelation coefficients other than the value 0 are entered in the codebook. The combination patterns which can be formed from these coefficients occur with the same frequency in the codebook. Because of these features, a transmission of encoded data which is very robust with respect to faults is possible with reduced processing and storage effort.

Abstract: A circuit of low complexity which selects arbitrary channels from a plurality of multichannel input signals and generates from a plurality of individual frequency channels a plurality of output signals whose channel composition can be freely selected, consists of a plurality of bandpass filters (BP1, BP2 . . . BPn) which are tuned to the individual frequency channels and whose input and output are respectively connected to a gate of one of a plurality of circulators (Z11, Z12 . . . Z1n; Z21, Z22 . . . Z2n) connected in a chain. In this case, at least two circulator chains are present (ZK1, ZK2), and a circulator (Z11, Z12 . . . Z1n; Z21, Z22 . . . Z2n) from one of the circulator chains can be optionally switched to the input and output of each bandpass filter (BP1, BP2 . . . BPn).

Abstract: The method of providing a frame clock for data signals in a communications network includes determining phase positions (P1, P2, . . . ) of respective frame clock information (RT1, RT2, . . . ) of incoming data signals with respect to frame clock information (RTN) available at a switching point in at least one switching device (NK1, NK2, . . . ); storing in a memory device (SPN) in the at least one switching device (NK1, NK2, . . .

Abstract: A method of coding digital image data of an original image for transmission and reproduction. The original image is subdivided into partial image regions whose shapes are adapted to local image structures. For each partial image region, a set of two-dimensional, lineraly independent basis functions is provided. The areal expanse of the basis functions approximately corresponds to the size of a rectangle circumscribing the partial image region to be coded and the raster of the sampled values of the basis functions corresponds to the pixel raster of the original image. The sampled values of the basis functions disposed within the area defined by the partial image region are orthogonalized in order to obtain a set of new, orthogonal basis functions, with the set including as many orthogonal basis functions as there are pixels within the partial image region. Coefficients of the orthogonalized basis functions describing the partial image region are then calculated.

Abstract: In a demodulator for a complex-value vestigial sideband signal, a Nyquist slope filter which consists of two subfilters (Ra, Ia) is used, a filter device (FBASTP) being connected downstream of, or also capable of being integrated in, the said Nyquist slope filter, in order to suppress subcarriers, specifically in such a way that the real parts (Ra) and imaginary parts (Ia) of the sub-filters can be combined in each case.

Abstract: A method is provided for linearizing variations in a transfer characteristic of a digital-to-analog (D/A) converter to which a digitized input signal is fed for being converted to an analog output signal. The method includes balancing the D/A converter so that essentially only negative differential variations result in the transfer characteristic at identified locations; determining amplitudes of the negative differential variations; and adding, with an inverse operational sign, the respective amplitudes of the negative differential variations to the input signal of the D/A converter at the respective locations of the variations.

Abstract: A method for reliability-controlled data detection of TDMA data bursts with a central test sequence for determining the identification parameters of the transmission channel, wherein: the data segments adjoining the test sequence at both ends are subdivided into N sectors A.sub.i, i=.+-.1, . . . ,.+-.N, with M sampled signal values each; in the kth processing step the sectors A.sub.1+, +1.ltoreq.i.sup.+ .ltoreq.=N are detected, suitable measures .LAMBDA..sub.i- and .LAMBDA..sub.i+ are determined for the detection results, and the detection result of the sector whose measure of reliability has the smaller value is rejected again if by then all sectors A.sub.-1, . . . , A.sub.i-+1 and A.sub.+1, . . . , A.sub.i+-1 have finally been processed; in the kth processing step the sector A.sub.i- is detected if -N<i.sup.- .ltoreq..sup.- 1 and all the sectors A.sub.i+, +1.ltoreq.i.sup.+ .ltoreq.+N have already been processed; in the kth processing step the sector A.sub.i+ is detected if +1.ltoreq.i.sup.

Abstract: For the preparation of data such as digitized television channel signals or television channel bundles, useful data are periodically replaced by a frame marker (F) in at least one of N parallel partial data streams of different bit significance. For this replacement, a partial data stream of low bit significance is selected because there the degradation is lowest. Because of this measure, the bit rate does not have to be increased in order to include a frame marker and a simple structure is possible for the multiplexer and demultiplexer at the respective transmission interfaces.

Abstract: A method for adaptation to the time-variable channel impulse response during a burst in receivers for TDMA mobile radio systems, each burst including in the center a test sequence which is known to the receiver and by means of which an initial estimate of the channel impulse response is possible, whereinthe received signal of a burst is suitably sampled,the received burst is divided in 2N+1 sectors A.sub.-N, . . . , A.sub.+N, it being assumed that the channel impulse response can be regarded as being constant within a sector,a vector x of dimension (2N+1)L is defined, L being the number of channel impulse response coefficients and the (iL+l)-th component of x, -N.ltoreq.i.ltoreq.+N, 0.ltoreq.l.ltoreq.L-1 is initialized before the start of the detection using the l-th coefficient of the estimated value of the channel impulse response obtained from the test sequence, Matrices E, E.sub.i, E.sub.ii, S and vectors x.sub.i, d, r.sub.

Abstract: A waveguide absorber which withstands high mechanical and thermal loads is typified in that a member (4) exhibiting absorber material is clamped between waveguide walls (5, 6) in such a way that at least one wall region (5) adjoining the member (4) is constructed flexibly, and that a force acting on the flexible wall region (5) presses the latter against the member (4).

Abstract: The process for production of an optoelectronic component having a predetermined coupling coefficient distribution and a predetermined phase shift distribution includes providing a photomask defining lateral and axial geometry of the grating fields of the optoelectronic compound, particularly predetermined curved grating boundaries between regions of the optoelectronic component having the grating fields and grating-free regions; performing a spin-on deposition of a photoresist on the semiconductor layers of a semiconductor substrate; structuring the semiconductor layers so that a DFB or DBR grating structure is located between the spin-on photoresist and the semiconductor substrate; after performing the spin-on deposition of the photoresist, exposing the photoresist using the provided photomask to form the optoelectronic component in the semiconductor substrate; and after the exposing of the photoresist using the photomask, etching surfaces of the optoelectronic component which are to be free of the grating

Abstract: The arrangement for coupling optoelectronic components and optical waveguides to one another includes a carrier substrate (11); at least one optoelectronic component (9) or one optical waveguide (1) secured on the carrier substrate (11) and at least one lens (8) provided with an essentially planar surface and a spherical surface located opposite the essentially planar surface. The carrier substrate is provided with a depression (5) for a lens (8) having walls and the lens (8) is inserted into the depression (5) so that the lens (8) rests with its spherical surface contacting the walls of the depression (5) at at least 3 points and is rotatable about its spherical curvature center point. An adjustment device for rotatably positioning the lens (8) in the depression and a method of securing the lens in position after an adjustment are described.

Abstract: A microwave line structure which has a first conducting track applied onto a substrate and a second conducting track which extends, supported on posts, at a distance above the first conducting track, a coplanar line being arranged, in addition to the microstrip line formed by the first conducting track and the second conducting track, on the substrate and coupled to this microstrip line, and the microstrip line extending between the two conducting tracks of the coplanar line, wherein, at one end of the coplanar line, the two conducting tracks of the latter are electrically conductingly connected to one another and to the first conducting track, wherein at the other end of the coplanar line the latter is open, wherein the length of the coplanar line is approximately equal to one quarter of the wavelength of the average operating frequency and wherein an asymmetrical line can be coupled to the first conducting track and the second conducting track at the short-circuited end of the coplanar line and a symmetrica

Abstract: The invention relates to an optical fiber amplifier having an amplification waveguide, having a pump source and having a wavelength-selective coupler. The pump light from the pump source is coupled into the amplification waveguide via the coupler. A carrier substrate (GS) is provided, on which passive (eg. couplers, dividers) and active components (eg. amplification waveguides) of the fiber amplifier are integrated. In addition, a silicon carrier (ST1) is provided, which is fitted to one end of the carrier substrate (GS). The silicon carrier (ST1) has anisotropically etched grooves with optical components. The pump source is fixed on the silicon carrier (ST1).The optical components on silicon carrier (ST1) and carrier substrate (GS) are adjusted in relation to one another.

Abstract: The waveguide multiplexer/demultiplexer includes a rectangular collecting waveguide provided with a short-circuit plane at one end thereof and elements for coupling the collecting waveguide to tunable waveguide filters arranged on opposing sidewalls, which are tunable to different frequency channels. The sidewalls are each provided with at least one pair of coupling openings. The two coupling openings of each pair are arranged side-by-side in a transverse direction relative to the waveguide longitudinal axis.

Abstract: A device for digital demodulation of the video and audio elements of a television signal has a digital preprocessing stage for conditioning a complex digital signal for digital demodulation of a television signal at intermediate frequency, a first complex mixing device shifting the video sub-carrier to the frequency 0, a common mixing device used on the input side for the demodulation of the audio signals, and the audio signal processing is not split until after this mixing device. Therefore, fully digital signal processing is possible for television signals from the intermediate frequency, with limited filter complexity.

Abstract: In a voltage converter for switching mode, for example a push-pull voltage converter (GW), during a starting operation the switching-on pulses for the switching elements (S1, S2) are dimensioned to be of different length, specifically in such a way that the mean value of the energy-consuming current does not exceed a prescribed limiting value.By contrast with conventional methods, there is no regulation of the switching-on pulses, but the different switching-on times in a plurality of subphases are prescribed in a fixed fashion as a function of the inductance (LS) of the DC/DC voltage converter (GW).The method according to the invention ensures that the mean value of the inrush current cannot become substantially higher than a prescribed nominal value. This is advantageous, in particular, for the power supply of travelling wave amplifiers. FIG.

Abstract: A device for processing a modulated real analog television signal has a digital preprocessing stage for conditioning a complex digital signal for digital demodulation of a television signal at intermediate frequency. The digital signal preprocessing is carried out such that subsequent demodulation of the video and audio elements can be carried out at a favorable cost. Therefore a fully-digital signal processing for television signals, from the intermediate frequency, with a limited filter cost is possible.