Showing papers on "Continuous phase modulation published in 1973"

Decision feedback loop for tracking a polyphase modulated carrier

Abstract: A multiple phase modulated carrier tracking loop for use in a frequency shift keying system is disclosed in which carrier tracking efficiency is improved by making use of the decision signals made on the data phase transmitted in each T-second interval. The decision signal is used to produce a pair of decision-feedback quadrature signals for enhancing the loop's performance in developing a loop phase error signal.

Linear phase microscopy.

Abstract: A technique is described for measuring the phase of complex transmitting objects. It consists of two basic parts. The first is an optical system that imposes the phase of an object onto a sinusoidal carrier in the form of a phase modulation. This is accomplished using interferometric and optical heterodyning techniques. The second is a phase detection system that converts this phase modulation into a signal that is directly proportional to the phase of the object. This technique measures phase variations from zero to 16π, (2π ambiguities are avoided) with a spatial resolution of 600 cycles/mm and a phase resolution of 2π/100. Analysis of this technique and experimental results are given.

Phase and frequency synchronizing circuit

Abstract: An inverter apparatus is disclosed for synchronizing a carrier wave form to a reference wave form to have a given frequency relation for controlling thyristor means. The carrier and reference frequencies are independently generated by a carrier generator and a reference generator to have a given frequency relationship. A detector determines the frequency difference of the carrier wave form from the given frequency relationship. An integrator interconnects the detector and carrier generator to modify the carrier frequency for resynchronization when the carrier wave form is leading or lagging the reference wave form at the given frequency relationship and for modifying the carrier phase when the carrier wave form is lagging the reference wave form at the given frequency relationship. The phase modification may include modifying the slope of the carrier wave form to contract a cycle thereof to phase synchronize the carrier with the reference wave form.

Means to prevent coincidental phase modulation in an amplitude modulation transmitter

Abstract: Means, including a voltage controlled oscillator in a phaselocked loop, whereby the transmitted carrier frequency is locked to a source of carrier frequency generation. The loop loop includes AM modulator AM modulator such that coincidental phase modulation is removed from AM transmitted AM modulated carrier.

Arrangement for carrier recovery in carrier frequency video and data transmission systems

Abstract: An arrangement for carrier recovery in carrier frequency video and data transmission systems comprising transmitting and receiving converters which operate with over modulation has a suppressed carrier modulator in the transmitting converter with a Nyquist filter connected to its output for creating a vestigial side band and a pre-emphasis circuit connected at the input for strongly damping low frequency signals so that a degree of modulation of less than 100% results in carrier frequency signals. The receiving converter includes a carrier recovery device having a band pass filter followed by a limiter. The limiter is connected to a demodulator and a de-emphasis circuit is connected to the output of the demodulator.

Optimum Deviation Ratio and Observation Interval for Continuous-Phase Binary Frequency-Shift Keying

Abstract: The optimum deviation ratio ( h =1/2 ) and observation interval (2-b periods) for a continuous-phase binary frequency-shift keying (CPBFSK) signal have been determined analytically for particular length sequences based on a squared-distance criterion.

An operator treatment of modulated carriers

Abstract: An operator treatment of modulated carriers in linear, time-invariant, nongenerative networks is given. The modulation is split up into an in-phase and a quadrature component. An operator (jω 0 + λ) is introduced, ω 0 /2π being the carrier frequency and λ the operator d/dt acting on the modulation only.

Sanky† continuous phase shifter for square waves ‡

Abstract: This paper describes the scheme as well as the circuit details of a phase shifter that, can be used to shift the phase of a square-wave signal continuously from 0° to 3011°. The phase is shifted linearly and continuously by the more adjustment of a potentiometer, which may be calibrated in degrees.

A study of integral pulse frequency modulation of a random carrier

Abstract: Integral pulse frequency modulation of a random impulse process is defined, and the general properties of one of its subclasses are studied. The power density spectrum is derived for the modulated output of one system of the subclass, namely the system where the carrier is a stationary Poisson process.