arXiv subjects

W. J. Szajnowski

Publications and source records attributed to W. J. Szajnowski.

4 recordsLinked to original sources

arXiv2021

Minimal Compression of a Radio-Frequency Pulse

Quadrature amplitude modulation (QAM) and a complementary representation of a causal waveform have been used to develop a sidelobe-free pulse-compression technique. Envelopes of radio-frequency (RF) pulses under study include both unimodal (Laplacian, Gaussian, rectangular) and bimodal (Hermite-Gaussian) shapes. Although the achievable compression gain is small (~2), the generation and phase-invariant correlation processing of such created compressible pulses can be accomplished with the use of low-complexity systems.

eess.SP↗

arXiv2020

A Class of Random Binary Waveforms With Impulse-Like Autocorrelation

It is shown that a random binary process with impulse-like autocorrelation can be generated by randomizing the length of symbols occurring in a random Bernoulli process. Such randomization is achieved by random (or judiciously designed irregular) sampling of the output of a source that supplies a symmetric random binary waveform. One practical configuration implementing the proposed technique is a linear-feedback shift register driven by a spread-period clock generator.

eess.SP↗

arXiv2018

Zero-Crossing Waveform Interferometry: an Alternative to Correlation in Signal Processing

It is shown that multiple representations (such as replicas or Hilbert transforms) of a random waveform can interfere constructively to form a compact pattern, akin to a wave packet, when the representations are created in synchrony with zero crossings of the waveform. A function of such 'engineered' zero-crossing interferograms can exhibit time-delay resolution superior to that associated with a conventional correlation function, especially for waveforms with slowly-decaying power spectra. A phenomenon of local slew rate at zero crossings is exploited to substantially reduce the Cramér-Rao bound on time-delay estimators. A system, based on a concept of elapsed time, is proposed to determine zero-crossing interferograms in real time.

eess.SP↗

arXiv2017

Estimators of the correlation coefficient in the bivariate exponential distribution

A finite-support constraint on the parameter space is used to derive a lower bound on the error of an estimator of the correlation coefficient in the bivariate exponential distribution. The bound is then exploited to examine optimality of three estimators, each being a nonlinear function of moments of exponential or Rayleigh observables. The estimator based on a measure of cosine similarity is shown to be highly efficient for values of the correlation coefficient greater than 0.35; for smaller values, however, it is the transformed Pearson correlation coefficient that exhibits errors closer to the derived bound.

stat.ME↗