Showing papers by "Nokia published in 1989"

System and method of scaling error signals of caseload second order modulators

Abstract: The invention relates to a method of cascading two or more sigma-delta modulators by applying an error signal representing the quantization error of a preceding modulator to a subsequent modulator in the cascade to be quantized therein, the quantized error signal being thereafter differentiated and subtracted from the quantized output signal of the preceding modulator. To improve the performance of the cascade, in the method according to the invention, the error signal is scaled before said subsequent modulator by a first factor smaller than 1, and the quantized error signal is scaled by a second factor substantially equal to the inverse of the first factor, before being subtracted from the quantized output signal of said preceding modulator.

Mounting base for a telephone device, such as a mobile telephone

Abstract: Mounting base for the transceiver of a mobile telephone for use in vehicles, the transceiver having a rigid boxlike enclosure. The mounting base (10) comprises a baseboard (12) having a main surface (20) and at least four sides (21, 22, 23, 24), at least three resilient brackets (14, 14', 14") extending from the sides of the baseboard. The brackets (14, 14', 14") have clips (16, 16', 16") at their free ends pointing inwardly over the baseboard. For mounting, the transceiver enclosure (110) is placed against the brackets and the transceiver bottom plate (112) against the baseboard (12) so that the bracket clips tightly snap on the transceiver upper edges. Pins (30) and recesses (40) cooperate with corresponding recesses and supports in the enclosure preventing the transceiver enclosure form moving relative the baseboard. The mounting base (10) is well suited for automatic production.

Interactive control of entertainment electronics apparatus

Abstract: The application describes how the control of entertainment electronics apparatus or combinations thereof can be simplified to the point that even an unpracticed user can make all necessary or desired adjustments as easily as possible. Even in a large combination, all functions can be controlled from a single control unit. The control unit has only a limited number of clearly arranged, distinct control elements.

A dividing cascade network for a support station in a radio telephone network

Abstract: The invention relates to a dividing network in the support station in a radio telephone network, wherein the received multi-channel antenna signal (ANT) is divided among sepa­rate receivers (CH1-CHn) by means of a dividing unit. The dividing unit is made up of a filter (2), an am­plifier (3) and a dividing network (1). According to the invention it has, in a cascade (11; 21), N directional couplers (H1-Hn; B1-Bn), there being branched out from the cascade in succession to each of the N receivers (CH1-CHn) a share, acording to the coupling (K1-kn) of the direc­tional coupler, of the filtered and amplified antenna signal (4).

Method of mounting a printed circuit board and securing the earthing to a casing

Abstract: Method of mounting a printed circuit board and securing the earthing to a casing. The method includes providing the printed circuit board with projecting parts and an earthing connection on at least one face, providing the casing with corresponding recesses, mounting the printed circuit board so that the projecting parts fit into the recesses to support the board, attaching a flexible sealing strip of electrically conducting material, and placing a lid on the sealing strip, whereby the earthing connection contacts the casing and the sealing strip, securing the earthing connection.

Remote control electrical device

Abstract: A remote control transmitter (3), which can be switched at a push button (4) and is held in the hand (2) of a user, of the remote control of an electric apparatus (1) generates radiation fields (5, 6) of differently identified carrier waves (7, 8) of different direction. The received field strength of the carrier waves (7, 8) received at a receiving element (14) of the remote control device are measured and from these control signals are formed in a direction detector which identify the angular deviation (Alpha) of the pointer direction (9) of the remote control transmitter (3) from a direction (13) on an optically visible marking element (12) and by this means call up operating commands for controlling the electrical apparatus (1) from a command memory via a command selector. In this manner, an electrical apparatus can be remotely controlled with great variety of operations by means of certain rotational movements of a remote control transmitter directed towards the electrical apparatus from the wrist without observation of the remote control transmitter exclusively by observing the remote-controllable electrical apparatus or a display (11) of this apparatus.

Combined analog/digital frequency modulator

Abstract: A circuit arrangement allows either analog (ANAL) modulation or (DIG) digital modulation to be selected by means of couplers (K1, K2) for transmission over a radio channel. The analog or digital signals are applied to I,Q generators to form I, Q wave shapes (I A , Q A or I D , Q D ), which modulate a possible intermediate frequency in a stage (3) and upon summation, modulate a transmission frequency in a stage (4).

Remote control transmitter for emitting control commands

Abstract: A remote control transmitter contains on a circuit board (3), which is rigidly connected to the transmitter housing (1) of the remote control transmitter, a positional-deviation switch configuration (17), which in the event of an angular deviation of the circuit board (3) and thus of the remote control transmitter beyond a particular trigger angle (ao) from a particular given or instantaneously determined reference operating position generates an output signal designating the direction of the positional deviation. In a signal converter (5) of the remote control transmitter, this direction-dependent output signal is converted as a control command into a transmission signal, and emitted via a transmitter element (4) of the remote control transmitter to a remotely controlled electrical appliance. By means of swivel movements of the remote control transmitter from the wrist of the user operating the remote control transmitter, different control commands to the remotely controlled appliance are generated in this way in the remote control transmitter.

Remote control arrangement

Abstract: For the remote control of a plurality of electrical devices (2, 3) which can be remote controlled in the same manner and having a single remote control transmitter (1), an address (A1, A2) of an address memory (16) is activated in a remote control receiver (14), said address characterising the remote control receiver (14) and causing the remote control receiver only to receive and evaluate such remote control signals (12) whose address part (AT) contains the address activated in the remote control receiver. The remote control transmitter (1) associated with this device group contains along the control panel (4) additionally a selection element (8), with which an associated address (A1, A2) is selected in an address transmitter (11) and in the transmission signal generator (7) fed to the address part (AT) of the radio-transmitted remote control signal (12).

A noise elimination method

Abstract: The invention relates to a method for the elimination of noise in an information channel. The frequency band of the channel (1) is first divided (CH1-CH4) into sub-bands (B1-­B4), whereafter the useful value of the signal of each sub-­band (B) is determined by comparing the signal level (S) to a reference level (Ref), in which case a constant signal of substantially the same level as the reference level (Ref) is suppressed (P1-P4), whereas a varying signal, defined as a useful signal, is summated, unsuppressed, with the useful signals of the other sub-bands (B1-B4). The frequency band of the channel is divided into sub-bands (CH1-CH4) by means of an all-pass filter construction. The method can be im­plemented using an analog or a digital filter construction.

Method of manufacturing a liquid-crystal cell

Abstract: A method of introducing the liquid crystal into a liquid-crystal cell is disclosed in which the liquid-crystal material is cooled to the solid state, ground to a grain size less than 50 micrometers, and subsequently sprinkled into the space formed by the spacer and a first substrate. The liquid-crystal cell is then covered and sealed with a second substrate in a vacuum. Thereafter, the liquid crystal is heated to a temperature above the clearing point. The liquid crystal cell can be used as a liquid-crystal display or as a light valve of an optical printer.

Circuitry for making a differential output single-ended

Abstract: Balanced mixers with respect to their output stages are created by making the differential mixer output (A, B) a single-ended output (C) without a matching transformer. The circuitry can be used in all balanced transistor mixers, provided that both sides of the differential output are available for use.

Black-white liquid crystal display having an insulation layer for blocking the diffusion of sodium ions from the glass of the cell plate to the polyphenylene of the orientation layer

Abstract: A black-white liquid crystal display (10) contains a nematic liquid crystal with a twist of 270° between cell plates. The product of the liquid crystal layer thickness and anisotropy of the refractive index is about 0.38. A pretilt of about 15° is present. The polarization directions (P1, P2) have an angle β of 45° to the orientation directions (Mo, Mu). This display features a very wide viewing angle range with relatively little dependence of the contrast on the viewing angle and there is an almost complete absence of color shift depending on the viewing angle. Due to the significant enhancement in viewing angle range in relation to contrast and color neutrality compared with all known cells, the display is called "Extended Viewing Angle" display (EVA display). It has a very high multiplexability.

A circuit arrangement for compensating for the thermal drift of a phase detector

Abstract: The invention relates to a circuitry for the compensation for the temperature drift of a phase detector (1) in a phase-locked loop which comprises a phase detector (1), a loop filter (2) and in the feedback branch a voltage con­trolled oscillator (3) coupled to the phase detector (1). According to the invention the phase detector (1) is pro­vided with a differential output (I and II), which is coupled to the input terminals (- and +) of the operational amplifier (4) in the loop filter (2), whereby the common-­mode temperature drift of the phase detector (1), appearing in the input poles of the operational amplifier, is sub­stantially eliminated in the output of the amplifier (Uout).

An intermediate chassis for a mobile telephone handset

Abstract: When the handset of an automobile radio telephone is being assembled, the parts of the handset are secured to a metal intermediate chassis (6), which at the same time serves as the ground plane of the handset. RF-shielding covers (9) can be secured to the intermediate chassis (6) in order to prevent RF-interference.

A method of cascading two or more sigma-delta modulators and a sigma-delta modulator system

Abstract: The invention relates to a method of cascading two or more sigma-delta modulators (A, B) by applying an error sig­nal (-Q1), representing the quantization error of a preceding modulator (A) to a subsequent modulator (B) in the cascade to be quantized therein, the quantized error signal (D2) being thereafter differentiated and subtracted from the quantized output signal (D1) of the preceding modulator (A). To improve the performance of the cascade, the method ac­cording to the invention is characterized in that the error signal (-Q1) is scaled before said subsequent modu­lator (B) by a first factor smaller than 1, and that the quantized error signal (D2) is scaled by a second factor substantially equal to the inverse of the first fac­tor, before being subtracted from the quantized output signal (D1) of said preceding modulator (A).

Digital mobile phone

Abstract: In a digital mobile phone based on time-division multiplexing (TDMA) a separate RF antenna switch is replaced by a duplex filter of the type used in analog technique.

Multi-dimensional sampling structure conversion with one-dimensional Nth-band filters

Abstract: Consideration is given to the design of a specific class of multidimensional filters which are used for sampling structure conversion of multidimensional sequences. Nonrectangular sampling structures are considered. The filter design is based on the concept of generalized separability, i.e. on the use of a cascade of one-dimensional filters operating in the direction of sampling vectors. The author considers the use of one-dimensional Nth-band filters, which result in improved computational efficiency, since the impulse response contains many zero-valued samples. Another advantage of these designs is that, in the interpolation case, the sample values of the input sequence are not changed, which is very natural in image interpolation. >

Method for the conversion of a video signal display frequency

Abstract: The invention relates to a method wherein it is possible, by digital signal processing taking place in the receiver, to reduce errors caused in a television picture by an in­terlaced transmission standard and a low field frequency. The transmitted interlaced (50 Hz/2:1) signal is converted in the receiver either to a non-interlaced (50 Hz/1:1) signal or to an interlaced (100 Hz/2:1) signal. The higher display frequency transfers the errors to higher frequen­cies, whereupon they no longer disturb the viewer. The conversion takes place by means of a weighted median filter operating in a 3*3 window. In the window, the first line is from the preceding field in the memory and the two others are from the latest received field. The filter interpolates a new dot according to these data. The structure of the filter selects implicitly temporal interpolation in a sta­tionary picture and spatial interpolation for moving ob­jects. By altering the coefficients of the weighted median filter it is possible to optimize the filter to operate either in a moving picture or in a stationary picture. The method can be carried out using a VLSI circuit.

Circuit arrangement for the generation of I,Q waveforms

Abstract: In a circuit arrangement for the generation of I,Q waveforms, an incoming analog signal controls a voltage-controlled oscillator (1), whose output signal (U1) is frequency-modulated. This signal (U1) is mixed with unmodulated signals by using mixers that are switches (6,7). The signals controlling the switches are either modulated or oscillator-generated rectangular waves. The circuit arrangement can be implemented as an integrated circuit.

Video receiving device

Abstract: The device described updates text pages in predetermined time intervals These pages can be accessed at any time The program locations are associated with page designations, that is to say in each case one program designation with page number As a result, pages can also be accessed which are transmitted in a program which does not correspond to the active program To program in such page designations, a program designation/page designation table is of assistance If paging is to be carried out between pages, this is done by shifting a cursor into margin areas of a text page All programs within the same time horizon can be paged through From the pages, transmissions can be selected for recording Transmission dates are transferred into a transmission/storage device In this device, a marking is set as soon as a recording has been concluded Either only marked or only unmarked transmissions can be optionally displayed If the transmission dates are stored in relation to cassettes, the possibility for cassette management is given To make the recordings as complete as possible, the device has the capability of automatically finding titles in text pages and entering these titles in the transmission/storage device

Antenna for radio telephone

Abstract: The present device concerns a small-size antenna for radio telephone. The antenna comprises two parallel, mu­tually spaced plates (21,22), the first plate (21) being electrically conductive and the second plate (22) being e.g. a glass fibre circuit board of which one surface is metal-­coated and on the other surface, facing the first plate (21), are disposed second or higher-order matching circuits (S) implemented with separate components.

Linearization of an amplification in an RF amplifier

Abstract: The invention relates to the linearization of an amplifica­tion in a radio frequency amplifier. The radio frequency amplifier (B) is coupled to a transmission signal line by means of connectors (TX IN, TX OUT). At points before and after the power amplifier stage (Q1, Q2, Q3) there are coupled directional couplers (Sk1, Sk2), on the basis of information from which the gain control circuit of the radio frequency amplifier (B) controls the power amplifier (Q1, Q2, Q3) in such a manner that its amplification is linear and constant.

Method and circuitry for automatic control of the frequency for a radio telephone

Abstract: A method and circuit for automatically controlling the frequency of a radio telephone. According to this method, the frequency of the signal detected at the receiver of a radio telephone is mixed with the output frequency of a phase-locked loop in a first mixer. The output frequency of the first mixer is mixed in a second mixer with the frequency derived from a local oscillator. The frequency of the phase-locked loop is controlled on the basis of the frequency deviation of the output frequency of the second mixer. This frequency deviation can be determined by counting the pulses generated by the second mixer during a predetermined time interval, the time interval being equal to the amount of time which elapses when a specified number of pulses generated by the local oscillator is counted. The reference frequency of the phase-locked loop is derived from the frequency of the local oscillator.

Method for electrically testing conductor tracks for short circuits

Abstract: The testing of conductor tracks for short circuits, particularly the testing of parallel matrix-like conductor tracks mounted on substrates requires a lot of time. A method is proposed in which a first group of conductor tracks is electrically connected to one another (12, 14, 16, 18, ...) whilst the conductor tracks of another group (11, 13, 15, 17 ...) are sampled individually in succession by means of a test probe. When a short circuit is present, an indicating instrument emits a visual or audible signal.

Supervised admission television system.

Abstract: This television system of the type comprising a television receiver including programme selection control means (3) and programme selection means (4), is characterised in that means (6) of supervising access to at least certain programmes are interposed between the selection control means (3) and the selection means (4). These supervising means can comprise: - means of authorising access to the programmes, - means of metering the access time, - means of interrupting access on expiry of a specified time.

Method of manufacturing the luminescent screen of a display device

Abstract: A method of manufacturing luminescent screens (2) for, e.g., color picture tubes is described. It uses a printing apparatus with heated printing blocks (3) and tampons (4). The printing inks (D) consist of a mixture of a hot-melt adhesive and the respective luminescent materials. The printing inks are printed from the printing blocks directly on the inside of the faceplate (1) of the color picture tube. It is also possible to first print a black matrix (M) of a ceramic glass color.

Method of manufacturing a control subassembly for flat display devices

Abstract: For a flat display device, a control subassembly is needed which consists of two control plates (1; 7) each formed by a layer of parallel conductors (2; 8) which are isolated from each other. During the manufacture of the control subassembly, the first control plate is provided with a glass frit in the form of continuous strips (10) perpendicular to the conductors. The glass frit is set, and the application of the strips is repeated. The second control plate is then put on the first control plate in such a way that their conductors are mutually perpendicular. After that, the glass frit is crystallized.