Abstract: A system for transmitting an n-level data signal (d.sub.k) at a given symbol rate 1/T comprises a data transmitter (1), a transmission channel (2) and a data receiver (3) with an equalizer (30) of the decision feedback type. By arranging this equalizer (30) for forming an estimate (c.sub.k) of a virtual m-level data signal (c.sub.k) instead of the output signal (b.sub.k) of the data transmitter (1) error propagation in the equalizer (30) is considerably reduced without thereby appreciably adding to the implementation-complexity of the system.

Abstract: A modified Booth multiplier for multiplying an m-bit number X by an n-bit number Y comprises a Booth encoder for converter the number Y in groups of 3 bits which overlap by 1 bit into a series Y' of multiplication values whose number is equal to or substantially equal to half the number of bits of Y. There is also provided a multiplex circuit for forming partial products from the number X and said series Y' and a matrix configuration of full adders for adding the partial products in incremental positions. The design is such that the constituent components and the operation of the modified Booth multiplier can be tested by means of a very small number of test patterns which are generated in the Booth multiplier after application of a specific series of X,Y-values.

Abstract: Radiological device of the pivoting type, comprising a fixed base (1), a longitudinal pivoting carriage (2) mounted on the base (1) and carrying, on the one hand longitudinally, a patient support panel (8) connected to the carriage by a patient support panel support, the panel support consisting of a bracket (3), the top horizontal beam (5) of which, which is mounted on an arm (6), forms a bridge for the passage of a practitioner.

Abstract: A method of transmitting at least two measured values by means of light pulses which are passed by an optical transmitter through an optical transmission path to an optical receiver and whose relative separation in time is proportional to the measured value. The energy consumption for the optical transmission of the measured values is reduced by transmitting needle pulses cyclically, one after another in the same order of succession, in that per measured value an optical measuring pulse is transmitted, whose separation in time from the optical measuring pulse associated with a preceding measured value is proportional the magnitude of the measured value, and in that for each group of measured values an optical identification pulse is transmitted, whose distance in time from a preceding measuring pulse is smaller than the smallest possible distance in time between two successive optical measuring pulses.

Abstract: A digital multiplier circuit which implements a modified multiplier algorithm in binary form and can be implemented as a very large scale integrated circuit. The modified algorithm replaces the large summation required in a typical shift-and-add digital multiplier with the sum of smaller summation terms, both yielding the same product. The digital word representing one of the multiplicands is partitioned or sliced into groups of two or more bits. All possible values of each bit slice are pre-calculated and stored to derive partial products thereof by the other multiplicand. The summation of such partial products rather than of individual bit products reduces the number of partial adders by half or more, depending on the number of bits in each partition or slice.

Abstract: A radio transmission system a base station comprises a plurality of transmitters arranged to transmit from the same site and having substantially the same output power, each transmitting on an individual channel within a dedicated block of contiguous channels. Receivers tuned to channels within said block of channels therefore require a limited image and adjacent channel rejection, of the order of 30 db. The receiver is preferably a direct conversion phasing receiver which has a local oscillator which can be tuned to a frequency within the block such that an image of any channel also falls within the block of channels. The system is suitable for local area radio systems such as paging or cordless telephones.

Abstract: A digital transversal filter which employs a multiplierless algorithm for effecting convolutions of samples of a digital input word by the filter coefficients. Each of the samples of an input word is bit sliced into segments of two or more bits, and convolutions are carried out in parallel on all segments using only adders and registers. The convolution products are then summed in a pipeline adder tree to derive the convolution of the complete input word. This architecture provides high frequency capability and significantly lower transistor count and hardware complexity, enabling efficient very large scale integration (VLSI) implementation.

Abstract: The invention relates to a method of generating a selective 180.degree. rf pulse is formed by means of two selective 90.degree. rf pulses. Halfway between the two rf pulses there is generated a non-selective 180.degree. rf pulse which ensures that the excited nuclear magnetization is independent of the homogeneity of the steady magnetic field of the magnetic resonance examination apparatus.

Abstract: In sorting an input file on the basis of parameter values of the objects, monotonically varying chains of the objects are formed first. In an inspection phase these chains are selected from which the selection objects will be found as k firsts of the selection objects in the output file, as well as the following selection object. Next, all the objects which on the basis of the parameter value need not function later than the (k+1).sup.th selection object are incorporated in a sub-file, transported to a direct sorting machine and, if necessary, the chain formation is then repeated.

Abstract: An arrangement for cancelling the composite echo signal formed by, for example, a linear component and a variable-phase component, comprises a linear echo canceller and a variable phase echo canceller, the difference circuits of these echo cancellers being arranged in cascade. The adjustable signal processing arrangements of each echo canceller are controlled for minimizing a predetermined function (mean square value or time average of this means square value), either of a residual echo signal appearing at the output of the difference circuit of this echo canceller itself or of a residual echo signal appearing at the output of the cascade arrangement of the difference circuits. In all cases the signal at the output of the linear echo canceller contains only a residual variable-phase signal which can be compensated for by the variable-phase echo canceller.

Abstract: A current mirror comprises a first branch in which a current to be duplicated (IE) flows and which comprises the main current path of a first transistor (T.sub.1), and a second branch in which the output current (Is), which is a replica of the input current, flows and which comprises the main current path of a second transistor (T.sub.2).In order to obtain a higher maximum output voltage the main current path of a transistor is arranged in the second branch in series with that of the second transistor.The bases of the first and second transistors are interconnected. A current I.sub.B is injected into the base of the series transistor and, if required, into the first branch. The current I.sub.B is suitably obtained by dividing a current 2I.sub.B derived from the base current I.sub.B of the first and second transistors.

Abstract: The invention relates to a digital circuit arrangement which comprises an interpolation filter which over samples a digital input signal, a noise shaper (1) following the interpolation filter (1), and a digital-to-analog converter coupled to the output of the noise shaper. The noise shaper includes a quantizer whose output signal is the output signal of the noise shaper. A quantization-error signal is formed which is passed through a limiter, filtered and added to the output signal of the interpolation filter to provide correction.

Abstract: This encoding arrangement has an input (12) for receiving a sequence of samples to be encoded, an output for supplying encoded samples, processing circuits, more specifically:a differential circuit (20) for producing differential samples between the samples to be encoded and prediction samples,a prediction circuit (22) to produce prediction samples from the encoded samples.It is characterized in that the processing circuits are separated into encoding units (E1, E2, E3 and E4) for each effecting a processing operation on each sample to be encoded and that an interleaving member (60) is provided to convert the sequence of samples to be encoded into a sequence of interleaved samples so as to ensure that all the processing operations to be effected on a sample are indeed effected.

Abstract: A magneto-optical waveguide device for changing the radiation modes propagating in the structure comprises a magneto-optical layer in which the modes propagate and which is externally magnetized. This magneto-optical layer is carried by a substrate and is connected to an optically anisotropic structure. This optically anisotropic structure is an artificially formed phase structure having zones of different refractive indices, the zones and their distances from each other in the direction of propagation of the modes being small relative to the wavelength of the light.

Abstract: An error supervision circuit for a non-encoded binary bit stream running through an elastic store comprising a memory having n locations, the bit rate of the stream supplied to the input of the memory differing from the bit rate of the stream produced at the output thereof. The successive bits in each group of n bits of the input stream are respectively written into the respective memory locations by write clock pulses supplied by a write register, at the input rate, and are successively read out from such locations by read clock pulses supplied by a read register at the output rate. The higher rate register is periodically interrupted for one or more bit periods to equalize filling and emptying of the memory. The bit streams at the input and output of the memory are supplied to respective data inputs of a comparator. A clock output of the lower rate register is connected to a first control input of the comparator to intermittently open a time window therein for receiving n bits of the lower rate bit stream.

Abstract: A magnetic resonance imaging apparatus includes a cascade of surface coils for detection so that larger objects can be measured while the attractive signal-to-noise ratio of surface coils is retained without mutual re-orientation of coils with respect to the object being required. By introducing a partial overlap between successive coils, suitable homogeneity can be achieved for the detection.

Abstract: Pixel information representing an image for display is coded using data compression. The data compression consists in obtaining the pixel information as a first matrix of high resolution pixel values, subtracting from this first matrix a second matrix composed of lower resolution pixel values, produced by low pass filtering the first matrix, to produce a third matrix of difference values, sub-sampling the second matrix to produce a fourth matrix of less density lower resolution pixel values and coding the third and fourth matrices. Complementary decoding consists in restituting the second matrix by interpolation filtering the decoded fourth matrix, and combining the restituted second matrix with the decoded third matrix.

Abstract: A method is proposed for the automatic correction of phase errors in NMR spectra. The phase errors are caused inter alia by deficiencies of the NMR hardware, by the shifted sampling of a magnetic resonance signal after the occurrence thereof.

Abstract: The invention relates to an examination apparatus with a mass balancing device. The balancing device comprises a compressed air cylinder which operates as a gas pressure operated spring. The internal pressure of the cylinder can be controlled, by a pressure control circuit in dependence of the sine of the pivot angle. A pressure control circuit is a control signal supplied by a sine generator. The sine generator generates a signal which is dependent on the sine of the pivot angle.

Abstract: Pixel information for image display is available in a mass memory as two sets of digital data of which, a first set represents values for the difference between pixel component values for an image of a given (enchanced) resolution and pixel component values for an image of lower resolution of the same pixel density, and a second set represents a lesser number of pixel component values for the lower resolution image but of reduced pixel density. In order to obtain pixel component values for displaying the enhanced resolution image, the first and second set of digital data are decoded and the pixel component values from the second set are expanded by interpolation and then added to the difference values from the first set. Different embodiments of display apparatus are described in which a display generator performs these operations in real time for a raster scan display device.