Showing papers by "Nokia published in 1988"

FIR-median hybrid filters with predictive FIR substructures

Abstract: A class of finite-impulse response (FIR) median hybrid (FMH) filters that contain linear FIR substructures to estimate the current signal value using forward and backward prediction is introduced. The output of the overall filter is the median of the predicted values and the actual signal value in the middle of the filter window. Predictors maximizing the signal-to-noise ratio on signal sections described by an lth-order polynominal are derived. The ramp enhancement filters are shown to attenuate the noise on a ramp signal better than the standard median (SM) filters. The new predictive FMH filters are shown to have root signals which do not exist for the SM filters, e.g. triangular waves. By combining the level and the ramp enhancement FMH filters, a filter is obtained which attenuates noise on constant and ramp signals. The noise attenuation on ramp signals is better than with the SM filter, and the predictive FMH filter has novel and meaningful root structures. The number of arithmetic operations needed to implement the predictive FMH filter grows linearly with the length of the filter. >

Method of growing GaAs films on Si or GaAs substrates using ale

Abstract: The invention relates to a method of growing a GaAs film on the surface of a Si or GaAs substrate by exposing the growing surface of the substrate in a vacuum to at least one vapor beam containing the Ga elementary component of the GaAs compound, and to at least one vapor beam containing the As elementary component of the GaAs compound. The method is characterized by the steps of (A) growing a GaAs buffer layer by alternately applying the elements of the GaAs compound to the surface of a substrate heated to a first temperature one atom layer at a time, whereby in the formation of each atom layer the growing surface is exposed to a vapour beam containing one elementary component of the GaAs compound only; and (B) heating the substrate to a second temperature higher than the first temperature, and growing another GaAs layer on the buffer layer by applying both of the elementary components of the GaAs compound simultaneously.

Method for locking to the user's card in a portable radio telephone

Abstract: The invention relates to a method for the use of a portable radio telephone, which has a processor (4) controlling and super­vising the operation, a keyboard (7) and a display (6), and a card reader (3), in which case, when the radio telephone is being used, the user identification data required by the radio telephone system are read from the card (1). The identification data (21) of the card (1) of the user authorized to use the radio telephone con­cerned are recorded in the non-erasable memory (5) of the processor (4), whereupon the radio telephone shifts into a mode locked to this card in such a way that its use is possible with only a certain card (1). By means of this method, protection is achieved against unauthorized use of the radio telephone.

Improving TV picture quality with linear-median type operations

Abstract: The FMH filter concept for video signal processing which combines the features of linear and median filters is introduced. In FMH (FIR median hybrid) filters, the overall output is the median calculated over the outputs of FIR subfilters, and the central input sample, the number of values to be sorted, is independent of the filter size; only the size of the FIR subfilters is altered. The noise reduction properties of FMH filters are similar to those of median filters. Applications within the field of digital enhanced TV, EDTV, and HDTV are presented with emphasis on noise suppression and image coding. >

A method for locating a mobile station, as well as a mobile station and a base station for carrying out the method

Abstract: A method for locating a mobile station, and a mobile radio telephone station and a fixed base station for carrying out the method. Identity signals and a precise time pulse are transmitted from fixed radio telephone stations (S1-S5) of known locations. The transmission takes place either as a response to an interrogation transmitted from the mobile station or automatically at predetermined intervals. All of the fixed stations are in highly precise chronological synchronization, and the transmission time of a precise time pulse may be only a specific one, for example, occur­ ring at 1-second intervals. As this interval is great com­ pared with the travel time of the time pulse, it is possi­ ble, by eliminating any multiples of the fixed time inter­ val, on the basis of the arrival time of the time pulses received at the mobile station, to calculate at any given time the distance difference between two fixed stations and, with the aid of at least three fixed stations, the location of the mobile station. All that the method re­ quires is supplementation of an existing radio telephone network, and the signals concerning the localization can be transmitted, for example, on the auxiliary carrier waves of the system.

RF-shielded hybrid circuit

Abstract: The invention relates to an RF-shielded hybrid circuit which comprises a printed circuit board (1) of an insulating material, with foils on both sides, components placed on one side of the printed circuit board, and an RF-shield housing (5) made of metal sheet and fitted around at least part of the circuit. It is the object of the invention to provide an RF-shield which can be manufactured automatically and which at the same time ensures a relatively simple and compact structure. In order to achieve this, the RF-shield for the circuit is made up on the one hand of a cup-like cover (5) the peripheral area of which extends substantially around the edge of the printed circuit board (1), with the exception of the area of the connectors (2) of the printed circuit board, and which is placed over the components, and on the other hand of an earth foil (2a) which faces away from the components of the printed circuit board and is soldered by its edge to the peripheral area (5a) of the cover (5).

Apparatus for cooling an optical fiber

Abstract: A method of and an apparatus for cooling an optical fibre drawn from a heated glass blank by passing the fibre (3) through a cooling pipe (9) in which a cooling gas (A) flows in the axial direction of the fibre around it. In order to reduce the consumption of cooling gas, the cooling gas is caused to flow turbulently (B) around the fibre by a throttle point (20) formed by a partition wall (19) in the cooling pipe, so that a laminar flow of cooling gas around the fibre is prevented and the transfer of heat between the cooling gas and the fibre is improved.

Signal processing requirements in pan-European digital mobile communications

Abstract: The authors give an overview of the basic functions and techniques of the user equipment of the proposed pan-European digital communications system. The multipath equalizer and channel decoder of the receiver together with the speech codec are identified to be the most complicated devices from the viewpoint of signal processing and integration. Three different approaches for implementation, using general-purpose digital signal processing (DSPs), application-oriented DSPs, and dedicated full custom VLSI, are discussed. With particular reference to the speech codec, a detailed analysis of the full-custom VLSI implementation is made and the results are compared with the other approaches. It is concluded that even though the full-custom approach offers considerable benefits in terms of power consumption and use of silicon area, other matters such as flexibility in operation and further development also have to be taken into account. >

Method and a device for the manufacturing of an optical coupler

Abstract: The invention relates to a method for the manufacture of optical couplers, comprising the steps of (a) removing the jacket material over a short distance from two or more optical fibres, (b) bringing the jacketless portions of the optical fibers in contact with each other, (c) fusing the optical fibers together within the contact area and drawing them into tapers. In order that the process would be simpler and easier to control, the method according to the invention is characterized in that the optical fibers are fused by heating them by means of an arc substantially parallel to the optical fibers. The arc is excited in a chamber confined in the direction of the radius of the fibers, and it is excited and extinguished at a low frequency so that the arc strikes at arbitrarily varying points around the fibers. The invention also concerns an oven for fusing fibers, comprising a fusion chamber extending through a ceramic body and provided at both ends thereof with an electric electrode for producing within the chamber an arc parallel to optical fibers arranged to be led through the chamber to be fused together.

A method of and an apparatus for cooling an optical fibre

Abstract: A method of and an apparatus for cooling an optical fibre drawn from a heated glass blank by passing the fibre (3) through a cooling pipe (9) in which a cooling gas (A) flows in the axial direction of the fibre around it. In order to reduce the consumption of cooling gas, the cooling gas is caused to flow turbulently (B) around the fibre by means of a throttle point (20) formed by a partition wall (19) in the cooling pipe, so that a laminar flow of cooling gas around the fibre is prevented and the transfer of heat between the cooling gas and the fibre is improved.

Method for depositing a solderable metal layer by an electroless method

Abstract: To deposit a solderable metal layer on conductive paths (4) of ITO on substrates of display devices (1) by an electroless method, the conductive paths are activated, prior to the deposition, and the areas not covered by the conductive paths are subsequently inactivated. The activated paths are then metallized with a solderable metal layer so that integrated circuits can be soldered to the metallized conductive paths.

High-voltage transformer for television sets

Abstract: The technical problem is to be solved to create a high-voltage transformer for television sets, in which the connection cables for the higher DC voltages are easily detachably attached. This problem is solved in that a sleeve is plugged onto the insulating material housing of the high-voltage transformer, which contains means for fastening the cables and interacts with fastening means on the insulating material housing.

Flat image display device

Abstract: The flat image display device, which is sealed in a vacuum, has a front plate (1) of glass, and a metal trough (2) as the rear side. On the inside of the front plate (1), there is a layer of fluorescent spots (3) and the electrodes required for use of the image display device are located inside the trough (2). These electrodes, i.e. a periodic arrangement of heating wires (4), a segmented opposing electrode (5) on a base plate (10), a perforated accelerating anode (6) inside a frame (11) and a control arrangement (7), are mechanically assembled into one component. In consequence, a stable construction for the electrodes is achieved which at the same time allows simple production of the flat image display device.

Video recorder with a device for recording an additional control track on a video tape

Abstract: A video recorder with a device (11) which, during the recording of a video performance onto a video tape (3), additionally records a control track (14) on the video tape and which, by the activation of a control input (27), records a second item of information on the control track. Each time the recording arrangement (7) of the video recorder is switched on, it is triggered in such a way that a start marking (22) is recorded as second item of information in the control track of the video tape (3) each time the recording mode of the recorder is switched on or each time the operating element (29) for this mode is actuated.

CMOS op amp dimensioning using multiphase optimization

Abstract: A dimensioning method for the design of class-A CMOS operational amplifiers is proposed. The method is based on forming an operating point equivalent of the circuit by virtue of given specification values. The operating point is then optimized to yield the best possible overall performance according to simulation results. The method is implemented in a dimensioning program called COARSE. >

Electron-gun system

Abstract: In a cathode-ray tube with a thick grid No. 2 (24) in the electron-gun system, current transfer into grid No. 2 (24) may result in a lack of picture sharpness. To avoid this error, the aperture (4) in grid No. 2 (24) has a widening (6) of conical shape or stepped diameter.

Graphite-containing conductive suspension for picture tubes

Abstract: A conductive suspension for making contact to the inside of a picture tube consists of graphite, glass-frit powder, a binder, such as nitrocellulose, a solvent, such as isoamyl acetate. It can be applied prior to or after the aluminizing process by various techniques, such as brushing, printing, or spraying, and permits the bake-out process and the frit-sealing process to be performed in one step because it is permeable to organic substances. It is easy to remove from defective tube parts by conventional cleansing techniques.

Cabel switching device

Abstract: A cable switching device to be used when switching from a first rotatable drum (3) to a second rotatable drum (4) for take-up of a cable (2) or the like. The novelty of the invention resides in that the cable switching device comprises a pivotable guide arm (13) supporting the cable (2) and adapted to be directed to the first (3) or, alternatively, the second (4) drum, or to a cutting device (20), the guide arm (13) comprising a nose portion (18) movable into and out of the drum (4 or 3), a clamping member (15, 16, 19) in the guide arm (13) for temporary clamping of the cable (2), the cutting device (20) being adapted to cut the cable at a given distance from the guide arm nose portion (18), and a catch arm (25) adapted to be inserted into the drum (4 or 3) through a suitable opening (23) in one of the drum sides (24) so as to take the cut-off free cable end (22) from the nose portion (18) inside the drum (4 or 3) and transfer it to a grapple (32) outside the drum (4 or 3), the grapple (32) being adapted to hold the cable end (22) and rotate together with the drum (4 or 3) during the subsequent winding of the cable (2) onto the drum.

Fernbedienungsgeber zur abstrahlung von steuerbefehlen

Abstract: Ein Fernbedienungsgeber enthalt auf einer Schaltungsplatte (3), die mit dem Gebergehause (1) des Fernbedienungsgebers starr ver­bunden ist, eine Lagedifferenzschalteranordnung (17), die bei einer Winkelablage der Schaltungsplatte (3) und damit des Fern­bedienungsgebers uber einen bestimmten Auslosewinkel (a₀) hinaus von einer bestimmten gegebenen oder momentan festgestellten Re­ferenzbedienungslage aus ein die Richtung der Lageabweichung kenn­zeichnenden Ausgangssignal erzeugt. Dieses richtungsabhangige Aus­gangssignal wird in einem Signalwandler (5) des Fernbedienungs­gebers als Steuerbefehl in ein Ubertragungssignal umgewandelt und uber ein Sendeelement (4) des Fernbedienungsgebers an ein fernzu­steuerndes elektrisches Gerat abgestrahlt. Durch Schwenkbewegungen des Fernbedienungsgebers aus dem Handgelenk des den Fernbedie­nungsgeber bedienenden Benutzers werden in dem Fernbedienungsgeber auf diese Art unterschiedliche Steuerbefehle an das fernzubedie­nende Gerat erzeugt.

An analog CAD system combining knowledge-based techniques with simulation and optimization

Abstract: The emphasis of research on intelligent CAD (computer-aided design) systems has been on knowledge-based techniques, and older, already established techniques such as optimization and simulation have attracted little attention. The authors argue that the combination of these different techniques would be superior to the use of a single technique and would result in important benefits in the CAD field. They are testing these concepts in a project developing a CAD system to support engineers in RF design. >

Method for the extraction of a substance from an aqueous solution

Abstract: The invention relates to a method for separating a substance from an aqueous solution and/or for concentrating it by using an organic extractant. In the method the substance to be separated is caused to pass from the aqueous solution to the extractant, whereafter this extractant is evaporated in direct contact with the aqueous phase into which it is desired to cause the substance to be extracted to pass.

An arrangement for connecting a hybrid circuit to a mother board

Abstract: The invention relates to an arrangement for connecting a hybrid circuit to a mother board, the hybrid circuit comprising a printed circuit board (1) of an insulating material, with foils on both sides, compo­nents fixed to the printed circuit board, and printed circuit board legs (2) by means of which the hybrid printed circuit board is connected to the mother board. The pur­pose is to achieve a connection which is maximally easy to manufacture and at the same time electrically and mechanically reliable. To achieve this, the legs of the printed circuit board consist of projec­tions (2) in the board (1) itself, and the mother board has apertures corresponding to the legs, the apertures not being copper-­plated throughout, in which case the earth foils and conductor foils in the projec­tions (2) are connected to the foils of the mother board at the edges of the apertures. The apertures in the mother board are pref­erably oval, corresponding in width to the thickness of the legs (2).

Manufacturing process for the phosphor screen of a picture reproduction apparatus

Abstract: A manufacturing process is described for phosphor screens (2) for e.g. colour picture tubes. In this case, a printing device is used with heated cliches (3M, 3R, 3G, 3B) and tampon coatings 4. The printing pastes (DR, DG, DB) consist of a mixture of a hot-melting adhesive and the respective phosphor materials. It is provided that the printing pastes are printed directly from the cliches onto the inner side of the front plate 1 of the colour picture tube. It is also possible to print a black matrix M, of a ceramic glass paint, in advance. … …

Phase-locked loop circuit

Abstract: The object of the description is a phase-locked loop circuit comprising eg in the form of an integrated circuit (IC) in sequential connection a digital phase comparator, to the input of which are supplied a reference frequency (fref), a loop filter and a voltage-controlled oscillator, from which a feedback branch is fed to the second input of the phase comparator The voltage (OV; OR) of the pulses obtained from the digital phase comparator is disposed so as to be adjustable, thus enabling to modify the limiting frequency and rate of the loop The adjustment of the voltage of the pulses can be carried out eg by adjusting the supply voltage of the phase comparator or by means of an exterior diode or transistor cutter (Q2, Q3) The circuit is usable eg in radiotelephone applications, in which a rapid loop is connected during channel switch

Extrusion equipment for applying a plastic sheath to a wire

Abstract: La bague porte-filiere (11) presente a son extremite amont le rebord tubulaire (12) muni de la collerette (12a) et cooperant avec les moyens de fixation de cette bague au support (1). The die holder ring (11) has at its upstream end the tubular flange (12) provided with the collar (12a) and cooperating with the fixing means of this ring to the support (1). Ces moyens de fixation comportent les quatre vis radiales (19) s'appuyant sur la portee cylindrique (13) du support (1) et permettant un decentrage controle de la bague par rapport au support, et d'autre part le collier de serrage (20) qui permet de placer les deux portees (14 et 15) dans des positions rigoureusement coaxiales. These fixing means comprise four radial screws (19) supported on the cylindrical bearing surface (13) of the support (1) and permitting controlled centering of the ring relative to the support, and secondly the clamp ( 20) that places the two bearing surfaces (14 and 15) under strictly coaxial positions. Les vis axiales (16) traversent le support (1), avec des jeux radiaux suffisants pour permettre l'ajustage. The axial screw (16) through the support (1), with sufficient radial clearance to allow the adjustment.

Color picture tube having internal conductive coatings

Abstract: In a color-picture tube, the conductive coating on the inside of the cone is a suspension without organic constituents The conductive coating on the inside of the neck, which is contiguous to the conductive coating on the inside of the cone, consists of the aforementioned suspension with an addition of organic constituents A sharp and scratch-resistant boundary between the conductive coating in the neck and the uncoated area of the neck is thus obtained