A space communications study Final report, 15 Sep. 1966 - 15 Sep. 1967

Investigation of signal to noise ratios and signal transmission efficiency for space communication system

Phase-locked Loop Dynamics in the Presence of Noise by Fokker-planck Techniques

Phase error behavior of phase-locked loop tracking system in presence of gaussian noise determined by fokker-planck equatio

A comparison of frequency estimation techniques for high-dynamic trajectories

A comparison is presented for four different estimation techniques applied to the problem of continuously estimating the parameters of a sinusoidal Global Positioning System (GPS) signal, observed in the presence of additive noise, under extremely high-dynamic conditions. Frequency estimates are emphasized, although phase and/or frequency rate are also estimated by some of the algorithms. These parameters are related to the velocity, position, and acceleration of the maneuvering transmitter. Estimated performance at low carrier-to-noise ratios and high dynamics is investigated for the purpose of determining the useful operating range of an approximate Maximum Likelihood (ML) estimator, an Extended Kalman Filter (EKF), a Cross-Product Automatic Frequency Control (CPAFC) loop, and a digital phase-locked loop (PPL). Numerical simulations are used to evaluate performance while tracking a common trajectory exhibiting high dynamics

Optimum and suboptimum frequency demodulation

Optimum and suboptimum linear demodulators for telemetry communication syste

Frequency division using cascaded phase-locked loops

In many practical communication systems it is necessary to generate phase coherent subharmonics of an input tone. A useful system for accomplishing this task is a system of phase-locked loops in cascade. It is shown that when the feed-forward function is matched, the phase error of the second loop is zero. Analytical analysis and computer simulation prove that the minimum time to achieve phase-lock is obtained when the feed-forward function is matched. Under this condition, necessary design parameters are determined with ease --Abstract, page i

Wide band frequency tracker performance and design of an all angle laser Doppler optical homodyne receiver, ground wind and wind tunnel measurements program, volume 2 Final report

Analysis and measurement of characteristics of wide band frequency trackers and design and fabrication of all angle laser Doppler velocimete

Digital phase-lock loop

An improved digital phase lock loop incorporates several distinctive features that attain better performance at high loop gain and better phase accuracy. These features include: phase feedback to a number-controlled oscillator in addition to phase rate; analytical tracking of phase (both integer and fractional cycles); an amplitude-insensitive phase extractor; a more accurate method for extracting measured phase; a method for changing loop gain during a track without loss of lock; and a method for avoiding loss of sampled data during computation delay, while maintaining excellent tracking performance. The advantages of using phase and phase-rate feedback are demonstrated by comparing performance with that of rate-only feedback. Extraction of phase by the method of modeling provides accurate phase measurements even when the number-controlled oscillator phase is discontinuously updated

The analysis of a phase-locked loop by the functional expansion method

The time response of a generalized second order Phase-Locked Loop to step and ramp inputs is described by a functional power, truncated at the third order term. The responses given by the functional power series differs from the analog simulation by less than 6% when the inputs are below 2.0 rad (rad/sec) --Abstract, page ii