Abstract: A burst-mode two-way radio communications system in which a plurality of antennas at a base station share a branched antenna switched dependent on the strength of the signal received from a portable transceiver, wherein a switch controller controls operation of one or more branch selection switches on the basis of an instructing signal received from any one of the base station transceivers.
Abstract: A communication device wherein leader pulses which continue for a predetermined time period are transmitted prior to the transmission of data from its transmitter; its receiver is rendered intermittently operative at a cycle shorter than half the continuation time of said leader pulses by means of a cycle operation controlling means to thereby become operative for a short time at a duty lower than 1/10; while the receiver is operating, it is detected by a detector means whether or not the leader pulses are transmitted; and when the transmission of the leader pulses is detected by the detector means, the receiver is kept operative for a predetermined time period by an operation holder means.
Abstract: An optical network is implemented by coupling of node switches to a single waveguide. The single waveguide can be connected, tail in mouth, to provide a low loss ring concentrator to which receiving and transmitting nodes are coupled via associated node switches. A processor also may be coupled by a node switch. Alternatively, the single waveguide may terminate at the processor.
Abstract: Disclosed is a spread spectrum communication system realized by using the frequency hopping coherent detection system wherein such an offset voltage pattern is predetermined by a polynomial is applied to the VCO of the PLL in the receiver thereof, so that the PLL can be operated with a narrow bandwidth because of the narrow bandwidth of the loop filter as well as a decreased loop gain while avoiding tracking break caused by narrow lock range due to the narrow bandwidth of the loop filter as well as the decreased loop gain.
Abstract: A heat-sensitive recording system for use in a facsimile communication network is provided. The present recording system is structured to use the same image information in multiple times under certain circumstances to keep the thermal recording head at a constant temperature. Accordingly, the image density of a recorded image is ensured to be uniform.
Abstract: A proximal cable-less communication system employs the physical placement of the units to each other to achieve information transfer. Local oscillators of each of the receivers are modulated and this modulated signal containing intelligence is received by other receivers due to the leakage radiation from the local oscillators.
Abstract: An equalizer is provided with a branching device for branching a digitally modulated signal into two outputs. A series of weighting devices weights one of the outputs of the branching means, and a series of second weighting devices equal to or fewer in number than the first weighting devices weights the remaining output of the branching means. Combining elements equal in number to the first weighting devices combine two or three inputs, and delaying means fewer in number than the combining elements are interconnected with the combining elements in a sequential, alternating manner. The outputs of the first weighting devices are respectively applied to the combining elements while those of the second weighting devices are respectively applied to selected ones of the combining elements. The invention provides a construction where the number of taps of the equalizer may be easily increased without creating the necessity of combining circuits having an increased number of inputs.
Abstract: A diversity reception radio receiver has a two-receiver system incorporating first and second receivers. A wave envelope detector is provided for each receiver to generate an output voltage corresponding to the strength of the electromagnetic signal wave which is picked up by the receiver. A hysteresis comparator compares the outputs of the two wave envelope detectors and generates a switching control signal. A switching device responds to the switching control signal by selecting between the signals which are repoduced by the first and second receivers. Because the amount of hysteresis in the comparator is automatically adjusted in accord with the strength of the signal wave, there is a minimum of hunting between the outputs of the two receivers.
Abstract: A method and apparatus for coloring a black and white film. The film is converted to video tape and the locations of edges of moving objects in frames of the video signal are used to develop a motion indicator key. The motion indicator key is used to reduce noise in the video signal without smearing motion and is used to assign colors to the black and white signal. For each scene of the black and white film, a color mask is produced for one frame. The adjacent frame is then colored the same as the initial frame except where motion is indicated. Where motion is indicated, a selected process assigns colors, for example based on direction of movement or grey levels of adjacent pixels. The new color mask thus produced is used as a reference for coloring the next frame. In this way the whole film may be colored, scene by scene. The color mask produced may then be combined with the black and white video signal to produce a colored video signal.
Abstract: A temperature compensating method an automatic diaphragm control amplifier used with an objective lens for a CCTV camera lowers or raises an adjusted level of video signal as an ambient temperature rises of lowers, respectively. The temperature compensating means compensates for a temperature-dependent variations in the DC component of the video signal coming from the camera and thereby to prevents the level of video signal from lowering as the ambient temperature rises or lowers.
Abstract: An image projection/imaging apparatus comprises a lens system, a light shutter, pattern forming means for forming an image pattern on the light shutter, projection control means for projecting the image pattern formed on the light shutter onto a focus plane by the lens system, photo-electric conversion means for converting the object image to an electrical signal, and imaging control means for projecting the object image onto the photo-electric conversion means through the lens system and the light shutter.
Abstract: A digitized quadrature phase shift keying modulator capable of making the modulation output frequency variable and sufficing a single ROM of waveform shaping digital filter with look-up table by using interpolators which re-sample waveforms of impulse response of each of the output I data and Q data from the digital filter to change the sampling rate and extractors for extracting the interpolated I data and Q data so that samples of each of the interpolated I data and Q data occur sequentially and alternately at different timings.
Abstract: A system for synchronizing a succession of horizontal deflection coil currents of a CRT display with a succession of synchronization signals includes a variable delay which is strobed by a synchronization signal and triggers the generation of a deflection current after a specified delay. The delay is automatically controlled by a feedback loop in which the present delay is measured by a set-reset flip-flop, the flip-flop providing an output pulse having a duration equal to the delay. An integrator averages a train of output pulses from the flip-flop, and combines a reference signal with the average value to provide the control signal for the delay. The system operates with minimal bandwidth and with dynamics which are free of acquisition constraints so as to provide minimal sensitity to noise.
Abstract: This circuit facilitates the synchronization of two copies of digital control units. These digital control units control a number of digital spans. One copy of this circuit is active at any one particular time. This one copy drives all the remaining circuitry of the digital span interface for both copies of the digital control unit. The other copy of this circuit is typically in the ready-standby mode. It is not actively driving the remainder of the circuitry within its own copy. When one copy of the digital control unit is brought on-line, a framing operation must be performed to determine the proper framing bit for both copies. Circuitry in the cross-copy data path monitors an attempt to synchronize the two digital control unit copies. The data which is sent cross-copy is modified so that all data bits are at logic 1, except for a bit which the active copy believes is the proper S-bit or framing bit.
Abstract: A digital subscriber line formed by terminal equipment, a network control device including a plurality of the terminal equipment, and an exchange terminal. In a waiting state of the digital subscriber line, the network control derive is placed in a state which can only receive a signal. A sending portion of the network control device is driven when, at a call from the terminal equipment, the terminal control device receives a line activation signal from the exchange equipment and when, at an incoming state from the state from the exchange terminal, the terminal control device receives a line activation from the exchange equipment. The synchronization pattern signal is sent from the sending portion to the exchange terminal so that the synchronization of the exchange terminal is established.
Abstract: An antenna diversity system for the mobile reception of frequency-modulated oscillations having a receiver, antennae and a diversity processor. An optimum system according to the invention includes an FM tuner with intermediate frequency part (2) and at least two antennae, while the diversity processor (3) receives an intermediate frequency signal or high-frequency signal, which corresponds to a given linear combination derived from the antenna signals. The diversity processor (3) further includes an FM demodulator (32) with a succeeding frequency sweep threshold detector (31) and a device by which, in dependence upon the occurrence of an interference-dependent frequency sweep pulse exceeding the frequency sweep threshold of the frequency sweep threshold detector (31) in the intermediate frequency of high-frequency signal, another linear combination derived from the antenna signals is supplied to the input side of the tuner with intermediate frequency part (2).
May 8, 1986
Date of Patent:
June 21, 1988
U.S. Philips Corporation
Heinz Lindenmeier, Ernst Manner, Gerhard Flachenecker
Abstract: A orderwire detector circuit operates to identify whether an orderwire signal is of a digital or of an analog format. The orderwire signal is conveniently combined with a high speed data signal. The circuit operates to filter the high speed data signal from the orderwire signal and then square and retime the orderwire signal by means of a stable clock source. The orderwire signal is delayed by one bit and these bits are then compared to determine whether or not over a long period a certain voltage exists. If the proper voltage level exists after a plurality of samples, then it is assumed that the orderwire signal is a digital signal. Depending on the voltage detected, at the end of a predetermined sampling period, one can therefore discriminate between a signal orderwire signal or a analog orderwire signal.
October 1, 1986
Date of Patent:
June 21, 1988
ITT Defense Communications, a division of ITT Corporation
Abstract: An office machine is disclosed, which comprises a second (lower) unit and a first (upper) unit capable of being opened and closed with respect to the lower unit. A plurality of light-emitting elements and a plurality of light-receiving elements are provided in the lower unit, and a plurality of light-emitting elements and a plurality of light-receiving elements are provided in the upper unit. The control signal and data signal are fed to the light-emitting elements to be converted into optical on-off signal. The light-receiving elements receive the optical signal and convert it into electric signal which is fed to necessary parts. Control signal lines and data signal lines between the two units are thus replaced with an optical relay.
Abstract: A picture image is scanned and identified as white and black portions according to the tone of the picture image to form a binary picture image signal. Picture images of tones other than white and black are detected and the detected picture image signals are modulated in accordance with predetermined modulation patterns. The modulated picture image signals are synthesized with the binary picture image signal.
Abstract: A collision detection mechanism includes a transmission protocol which locates a gap in a station's transmission, of fixed duration and position, relative to start of transmission. Collision detection is enhanced since random timing of collisions normally results in filling in the gap. This condition is more readily detectable than detecting the simultaneous presence of energy from two transmitters. The transmission protocol is followed unless the transmitting station detects a collision, in which event gap creation is inhibited. The gap detecting equipment may be located at a network head end.