scispace - formally typeset
Search or ask a question

Showing papers on "Keying published in 1977"


Journal ArticleDOI
TL;DR: Modulation and demodulation in the minimum (frequency)-shift keying (MSK) format are reduced to the form of coherent biphase keying, demonstrating the feasibility of synthesizing the one filter that is unique to this signaling scheme.
Abstract: Modulation and demodulation in the minimum (frequency)-shift keying (MSK) format are reduced to the form of coherent biphase keying. Considerable simplification of circuitry is thus effected without sacrifice of performance. When the ratio of the carrier frequency to the bit rate is high, then the technique described here does not require the precise relative phasing of any pair of oscillators in the transmitter. Experimental results demonstrate the feasibility of synthesizing the one filter that is unique to this signaling scheme. In the present instance, the filter is realized as a surface acoustic wave device.

127 citations


Journal ArticleDOI
TL;DR: The authors compared two approaches to scoring a Psychological Climate Questionnaire, an empirical keying of items using item analysis and a rational approach which focused on identifying the salient features of the questionnaire items.
Abstract: The present study compared two approaches to scoring a Psychological Climate Questionnaire— an empirical keying of items using item analysis and a rational approach which focused on identifying the...

22 citations


Journal ArticleDOI
TL;DR: A suboptimal receiver of constant envelope, continuousfrequency MSK-type modulations called Continuous Shift Keying (CSK) is proposed that halves demodulator complexity with no more than a 1.6 dB loss in detectability in AWGN.
Abstract: A suboptimal receiver of constant envelope, continuousfrequency MSK-type modulations called Continuous Shift Keying (CSK) is proposed that halves demodulator complexity with no more than a 1.6 dB loss in detectability in AWGN. The technique is especially applicable to a frequency division multiple access system composed of many unsynchronized user terminals.

16 citations



Journal ArticleDOI
A. Weinberg1
TL;DR: A comparison of present results with those of previous ones for corresponding CPSK systems shows that DPSK is degraded noticeably more by downlink noise than its CPSK counterpart.
Abstract: Although the effects of a hard-limiting repeater on coherent phase shift keying (CPSK) data transmission systems have been studied, corresponding effects pertaining to differential phase shift keying (DPSK) systems are yet to be examined. The present paper contains the results of a study on DPSK data detection performance when a hard-limiting repeater is part of the overall data link under consideration, and white Gaussian noise is introduced at the repeater and receiver front ends; the extension to the multi-link system, containing cascaded hard-limiting repeaters, is also included. The results obtained were found to be analogous to those of previous CPSK studies. Specifically, the inclusion of the hard-limiter was generally shown to improve probability of error performance when downlink noise is present. A comparison of present results with those of previous ones for corresponding CPSK systems shows that DPSK is degraded noticeably more by downlink noise than its CPSK counterpart.

10 citations


Patent
Ootani Susumu1, Noguchi Toshitake1
19 May 1977
TL;DR: In this article, a circuit for extracting a clock signal from a double-binary phase-shift keying system is presented, where the carrier wave form is regenerated at the receiver from the PSK signal input.
Abstract: A circuit for extracting a clock signal from a double-binary phase-shift keying system is disclosed. The carrier wave form is regenerated at the receiver from the phase-shift keyed (PSK) signal input. The regenerated carrier wave is frequency doubled and frequency mixed with the PSK input signal which has also been frequency doubled. A desired clock signal is thereafter extracted from the mixed signal by a band-pass filter. The system does not include a frequency divider which would result in a phase ambiguity.

8 citations


Patent
12 May 1977
TL;DR: An image brightness control arrangement for a color video signal processing system including a plurality of amplifiers each responsive to luminance and separate color difference signals for developing color representative output signals is described in this article.
Abstract: An image brightness control arrangement for a color video signal processing system including a plurality of amplifiers each responsive to luminance and separate color difference signals for developing color representative output signals. A brightness control (e.g., a potentiometer) also is included for varying a brightness determinative D.C. level of the luminance signal. A locally generated periodic keying signal, occurring during periodic image blanking intervals of the video signal and of a magnitude which may vary undesirably, is coupled to each of the amplifiers for establishing a reference level for the color difference signals, as described in U.S. Pat. No. 3,970,895. A derived signal indicative of the magnitude of the keying signal is coupled to the brightness control for establishing a brightness control range thereof.

7 citations


Patent
07 Nov 1977
TL;DR: In this paper, the LED's are mounted in a field for image reproduction, esp. for position finders. Control signals representing brightness information are applied to comparators, and a common function generator is connected to their other inputs.
Abstract: The LED's are mounted in a field for image reproduction, esp. for position finders. Control signals representing brightness information are applied to comparators, and a common function generator is connected to their other inputs. The generator voltage continuously rises and/or falls, and serves as a reference signal (UR). A pulse train appears at the outputs of the comparators whose keying ratio varies in accordance with the control voltages (US). This pulse train is used as the LED voltage (UL).

6 citations


Patent
24 Nov 1977
TL;DR: In this article, the received phase keyed signal is complex demodulated and digitalised, and the complex base band signal components are filtered through digital channel filters with different bandwidths but the same center frequency signal amplitude and phase is measured for each channel.
Abstract: The received phase keyed signal is complex demodulated and digitalised, and the complex base band signal components are filtered through digital channel filters with different bandwidths but the same centre frequency signal amplitude and phase is measured for each channel. The clock pulse times at which the amplitudes are measured and instantaneous phases determined are obtained from the amplitude values of their square by narrow band filtering. The differences between two consecutive phases in each channel are stored in the form of a histogram, from which the phase keying, the number of phase states, receiver tuning conditions and the approx. cycle rate in real time are recognized. These parameters are determined by cross-modulation with modulation matched reference functions and testing the amplitude of the filtered out clock signal.

5 citations


Patent
08 Aug 1977
TL;DR: In this article, the phase comparison relaying scheme is proposed where the keying threshold levels at the local and remote ends of a protected power line section are each offset by a different value from the effective zero axis of the current waveform.
Abstract: MODIFIED OFFSET KEYING APPARATUS FOR PHASE COMPARISON RELAYING ABSTRACT OF THE DISCLOSURE Phase comparison relaying apparatus wherein the keying threshold levels at the local and remote ends of a protected power line section are each offset by a different value from the effective zero axis of the current waveform. One of the keying threshold values is set at a magnitude which will cause a trip response in the presence of low or medium magnitudes of outfeed current. The other keying threshold level is set at a magnitude which will cause a trip response in the presence of maximum magnitudes of expected outfeed current. The upper and lower current margin threshold levels are set to appropriately reflect the keying threshold level with which they are respectively associated. In addition, the transmitter having the higher keying threshold level is located at that end of the pro-tected line section where outfeed is expected.

3 citations


A. Weinberg1
01 Oct 1977
TL;DR: In this paper, the results of a study on differential phase shift keying (DPSK) data detection performance when a hard-limiting repeater is part of the overall data link under consideration, and white Gaussian noise is introduced at the repeater and receiver front ends.
Abstract: Although the effects of a hard-limiting repeater on coherent phase shift keying (CPSK) data transmission systems have been studied, corresponding effects pertaining to differential phase shift keying (DPSK) systems are yet to be examined. The present paper contains the results of a study on DPSK data detection performance when a hard-limiting repeater is part of the overall data link under consideration, and white Gaussian noise is introduced at the repeater and receiver front ends; the extension to the multi-link system, containing cascaded hard-limiting repeaters, is also included. The results obtained were found to be analogous to those of previous CPSK studies. Specifically, the inclusion of the hard-limiter was generally shown to improve probability of error performance when downlink noise is present. A comparison of present results with those of previous ones for corresponding CPSK systems shows that DPSK is degraded noticeably more by downlink noise than its CPSK counterpart.

Patent
27 Jan 1977
TL;DR: In this paper, an electronic keying circuit which delivers pulses at short intervals for keying the modulated transmitted carrier frequency, has a sender with at least one active stage before its output stage.
Abstract: An electronic keying circuit which delivers pulses at short intervals for keying the modulated transmitted carrier frequency, has a sender with at least one active stage before its output stage. A pulse shaper is allocated to the output stage and each preceding stage, and a common timer is provided for all pulse shapers. The timer delivers approximately rectangular individual keying pulses having the same period, to each pulse shaper. Pulses for the individual pulse shapers differ in width and phase, so that the output stage is switched on after preceding stages, and switched off before them. The pulse shapers round off the edges of the pulses from the timer.

Patent
12 Mar 1977
TL;DR: The tip parts of plunger for performing continuous keying are formed by main part and bag-shaped silicon rubber materials; condenser is installed to conduction circuit Thus, the keying properties is approximated to that of fingers, improving dependability as mentioned in this paper.
Abstract: PURPOSE:The tip parts of plunger for performing continuous keying are formed by main part and bag-shaped silicon rubber materials; condenser is installed to conduction circuit Thus, the keying properties is approximated to that of fingers, improving dependability

Patent
21 Jul 1977
TL;DR: In this paper, the phase comparison relaying is performed at one terminal by unsupervised circuitry to generate an echo trip signal which is employed to effect breaker tripping at the other terminal.
Abstract: OF THE DISCLOSURE Phase comparison relaying apparatus associated with the local and remote end terminals of a protected line section wherein the phase comparison is performed at one terminal by unsupervised circuitry to generate an echo trip signal which is employed to effect breaker tripping at the other terminal Additional circuitry supervises the gene-ration of a breaker trip signal for use et the terminal where the echo trip signal is generated without preventing generation and transmission of the echo trip signal The use of such circuitry is described in the operating context of phase comparison relaying apparatus adapted to utilize offset keying Also described is the effectiveness of such circuitry during open breaker or zero-feed conditions

Patent
04 May 1977
TL;DR: In this paper, a three phase solid relay designable the increase in the free degree in the contition of thtucircuit in safety by measn of performing power make and break without contacts, moreover electrically insulating the power keying part and keying control signal input part.
Abstract: PURPOSE:Three phase solid relay designable the increase in the free degree in the contition of thtucircuit in safety by measn of performing power make and break without contacts, moreover electrically insulating the power keying part and keying control signal input part.

Patent
09 Jun 1977
TL;DR: In this article, the output corresponding to 2 to OR was used as the strobe signal to secure stabilized circuit operation as well as decrease the parts number by giving only the output corresponding to 2-to-OR circuit and then utilizing the output as the STM signal.
Abstract: PURPOSE:To secure stabilized circuit operation as well as to decrease the parts number by giving only the output corresponding to 2 to OR circuit and then by utilizing the output as the strobe signal.

Journal ArticleDOI
TL;DR: In this paper, a homodyne scheme for implementing a broadband impedance indicator is proposed, which features a simple form made possible by using a modified quarternary phase-shift keying as a subcarrier modulation method.
Abstract: A novel homodyne scheme for implementing a broad-band impedance indicator is proposed. It features a simple form made possible by using a modified quarternary phase-shift keying as a subcarrier modulation method. This method allows both the amplitude and the phase of a signal to be detected simultaneously by one single-ended mixer. A prototype indicator has assured the swept-frequency measurement over the band ranging from 8.6 to 10.4 GHz with the amplitude and phase errors of less than 5 percent and 5°, respectively. The capabilities are demonstrated by presenting examples of measurement.

Patent
08 Jun 1977
TL;DR: In this paper, a dynamic one finger chording system with memory is connected in parallel relationship to the d.c. level voltage signal corresponding to a manually depressed key is detected, and an identification of the detected line is used as the address to a read only memory.
Abstract: A dynamic one finger chording system with memory is connected in parallel relationship to the d.c. keying lines connecting a select number of keys of the manual to a standard keyer circuit of an electronic organ. The one finger chording system scans each keying line until a line with a d.c. level voltage signal corresponding to a manually depressed key is detected. An identification of the detected line is used as the address to a read only memory. In response to the address, the read only memory provides a preselected d.c. level output signal which through appropriate output circuits drives respective keying lines. Thus one keying line has a d.c. level signal due to the manual depression of a key and a predetermined number of keying lines have a d.c. level signal due to the output signal from the one finger chording read only memory. The same keyer circuit that is used during normal playing now provides a chord output signal. When the key is released by the instrument player, the one finger chording system begins to scan the keying lines for the next key depressed. If a new key is depressed without releasing the previously depressed key, the one finger chording system removes itself from the respective keying line of the previously depressed key before beginning the scan for the new keying line with a d.c. level signal. Furthermore, upon depression of a key the system receives a load pulse of finite duration which momentarily disables the scanning and clears the one finger read only memory output so that when the scanning is resumed for the new d.c. level signal it is not confused by the previous d.c. level signal output from the read only memory. The one finger chording system has a memory mode actuatable by the instrument player and which electrically sustains the selected one finger chord after the instrument player releases the depressed key and until a new key is depressed or the memory feature deactivated.

PatentDOI
TL;DR: In this paper, a digital keying system for an electronic musical instrument, such as an electronic organ, comprises a digital percussion generator which synchronizes the operation of a variable attentuator with the zero crossings of a sine wave signal applied to the input of the attenuator from a waveform generator.
Abstract: A digital keying system for an electronic musical instrument, such as an electronic organ, comprises a digital percussion generator which synchronizes the operation of a variable attentuator with the zero crossings of a sine wave signal applied to the input of the attenuator from a waveform generator. Pulses from a rhythm generator are applied to a coincidence gating circuit along with pulses corresponding the zero crossings of the sine wave signal from the waveform generator to synchronize the stepped operation of the variable attenuator with the zero crossings of the sine wave signal applied to it.

Patent
02 Jun 1977
TL;DR: In this article, the information (N) is applied to the input of a first filter with rectifier (1) and to the output of a delay line (2), the delay line output is passed to a second filter with Rectifier (3) and the outputs of the two filters are connected to the inputs of a gate (4) whose output is used to operate the transmitter keying relay.
Abstract: The keying circuit for a radio transmitter, uses presence or absence of information for transmission to switch the carrier wave on and off respectively without loss of information. The information (N) is applied to the input of a first filter with rectifier (1) and to the input of a delay line (2). the delay line output is passed to a second filter with rectifier (3). The two filter with rectifier circuits remove noise and allow only the largest amplitude information signals to pass through. The outputs of the two filter and rectifier circuits are connected to the inputs of a gate (4) whose output is used to operate the transmitter keying relay.

Patent
09 Jun 1977
TL;DR: In this article, the image formation and display is given to Chinese character group via laser beam, and an optional letter among displayed Chinese character groups is designated, and the coordinate signal corresponding to the position of the optionally designate letter is generated.
Abstract: PURPOSE:The image formation and display is given to Chinese character group via laser beam. At the same time, an optional letter among displayed Chinese character group is designated, and the coordinate signal corresponding to the position of the optionally designate letter is generated. In this way, the simplification of keying operation as well as high-efficiency correction for mistaken characters can be realized.

Patent
08 Aug 1977
TL;DR: In this article, the authors propose to recover the normality by detecting the abnormality in the porality of output as soon as possible without affecting the synchronism for block of decoder in case of the output of demodulation keying etc.
Abstract: PURPOSE:To recover the normality by detecting the abnormality in the porality of output as soon as possible without affecting the synchronism for block of decoder in case of the output of demodulation keying etc..

Patent
03 Mar 1977
TL;DR: In this paper, a keying arrangement is based on the fitting of two or more keys into the platform of the main unit or chassis, each key having a short spindle locating with holes in the base of the unit to be fitted.
Abstract: Keying system preventing the fitting of incorrect units or to ensure the exact positioning of a unit or sub-unit with respect to some other unit. The design allows the key to be altered such that a different unit may be installed if required. The keying arrangement is based on the fitting of two or more keys (2) into the platform of the main unit (1) or chassis, each key having a short spindle (3) locating with holes in the base of the unit (5) to be fitted. Each such key is square or hexagonal in section with the spindle offset from its center. The key is a permanent magnet and the base (6) of its socket is of some ferromagnetic material.

Journal ArticleDOI
01 Dec 1977
TL;DR: In this article, a phase-script logic element is used to reconstruct phase-shift keying signals at carrier frequency without the need for down-conversion and an analysis of the switching performance of such regenerators is presented and applied to two specific circuit realisations.
Abstract: A novel method of regeneration of digital phase-modulated (phase-shift keying) signals is proposed, analysed and demonstrated using a parametric-subharmonic oscillator (p.s.o.) as a phase-script logic element. This technique of regeneration proceeds at carrier frequency without the need for down-conversion. An analysis of the switching performance of such regenerators is presented and applied to two specific circuit realisations. A switch-on time of 2ns and switch-off time of 1.5ns have been measured with a varactor diode p.s.o. at 8.2 GHz, hence demonstrating the feasibility of regeneration at 150 Mbits. A working regenerator is demonstrated at 4 GHz with a measurement of signal-to-noise/error-rate performance at 10 Mbits.