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- Keyword
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- Broadband, chirp modulation, underwater, communications (1)
- Calibration (1)
- Carrier phase estimation, quadrature amplitude modulation, phase-shift keying, general constellations, synchronization, blind estimation, asymptotic performance (1)
- Fractional Fourier transform, impulse response, sonar signal processing, Wigner distribution, volume search sonar (1)
- Quadrature-quadrature phase shift keying, constant envelope, optimum detector, four-dimensional modulation (1)
Articles 1 - 6 of 6
Full-Text Articles in Engineering
Single-Layer-Coated Beam Splitters For The Division-Of-Amplitude Photopolarimeter, Rasheed M.A. Azzam, Faisal F. Sudradjat
Single-Layer-Coated Beam Splitters For The Division-Of-Amplitude Photopolarimeter, Rasheed M.A. Azzam, Faisal F. Sudradjat
Electrical Engineering Faculty Publications
A design procedure is presented for a near-optimal, single-layer-coated prism beam splitter that serves as the key optical element of the division-of-amplitude photopolarimeter (DOAP). For given film and substrate refractive indices, the angle of incidence and film thickness are selected such that the ellipsometric differential phase shifts in reflection and transmission Delta_r and Delta_t differ by ±pi/2, and the normalized determinant of the instrument matrix is maximized. The best results are obtained by using high-index films on low-index substrates. This is illustrated by examples of ZnS and GaP films on silica prisms in the visible and Si, Ge, and PbTe …
Chirp Slope Keying For Underwater Communications, Edit J. Kaminsky, Lastri Simanjuntak
Chirp Slope Keying For Underwater Communications, Edit J. Kaminsky, Lastri Simanjuntak
Electrical Engineering Faculty Publications
This paper presents a novel broadband modulation method for digital underwater communications: Chirp Slope Keying (CSK). In its simplest form, the binary information modulates the slope of a linear chirp, with up-chirps representing ones and down-chirps representing zeros. Performance evaluation in the form of probability of error vs. SNR show that the system performs as expected for AWGN environments and very well for more realistic models for underwater acoustical communications, such as the Raylegih channel with Doppler, delays, phase offset, and multipath.
Sonar Signal Enhancement Using Fractional Fourier Transform, Madalina Barbu, Edit J. Kaminsky, Russell E. Trahan
Sonar Signal Enhancement Using Fractional Fourier Transform, Madalina Barbu, Edit J. Kaminsky, Russell E. Trahan
Electrical Engineering Faculty Publications
In this paper we present an approach for signal enhancement of sonar signals. Work reported is based on sonar data collected by the Volume Search Sonar (VSS), as well as VSS synthetic data. The Volume Search Sonar is a beamformed multibeam sonar system with 27 fore and 27 aft beams, covering almost the entire water volume (from above horizontal, through vertical, back to above horizontal). The processing of a data set of measurement in shallow water is performed using the Fractional Fourier Transform algorithm. The proposed technique will allow efficient determination of seafloor bottom characteristics and bottom type using the …
Asymptotic Performance Of The Pth Power-Law Phase Estimator, Kenneth V. Cartwright, Edit J. Kaminsky
Asymptotic Performance Of The Pth Power-Law Phase Estimator, Kenneth V. Cartwright, Edit J. Kaminsky
Electrical Engineering Faculty Publications
An expression for the true variance of the Pth powerlaw phase estimator, as the number of samples approaches infinity, is given. This expression is an extension to the linear approximation of Moeneclaey and de Jonghe [1] which is known to be inadequate in some practical systems. Our new expression covers general 2π/P-rotationally symmetric constellations that include those of PAM, QAM, PSK, Star M-QAM, MR-DPSK, and others. This expression also generalizes the known expressions for QAM and PSK. Additionally, our expression reduces to the Cramer-Rao bound given by Steendam and Moeneclaey [9], as SNR goes to zero. Monte Carlo simulations provide …
Blind Phase Recovery In Cross Qam Communication Systems With The Reduced Constellation Eigth-Order Estimator (Rceoe), Kenneth V. Cartwright, Edit J. Kaminsky
Blind Phase Recovery In Cross Qam Communication Systems With The Reduced Constellation Eigth-Order Estimator (Rceoe), Kenneth V. Cartwright, Edit J. Kaminsky
Electrical Engineering Faculty Publications
The eighth-order (EOE) phase estimator [4] is modified to work for an eight-symbol symmetrical constellation, so that the large signal-to-noise (SNR) performance is not limited by self-noise. By using only the eight highest energy points of cross- QAM constellations, a reduced constellation eighth-order estimator (RCEOE) is proposed. Computer simulations for 128-QAM show that this new method performs substantially better than the recently introduced APP phase estimator of Wang et al. [8]. However, simulations with 32-QAM show little performance advantage of the RCEOE over the APP estimator, for SNR values normally of interest, whereas for low SNR, the improvement is significant. …
An Optimum Hardware Detector For Constant Envelope Quadrature-Quadrature Phase Shift Keying (Ceq2osk), Kenneth V. Cartwright, Edit J. Kaminsky
An Optimum Hardware Detector For Constant Envelope Quadrature-Quadrature Phase Shift Keying (Ceq2osk), Kenneth V. Cartwright, Edit J. Kaminsky
Electrical Engineering Faculty Publications
A hardware detector for constant envelope quadrature- quadrature phase-shift keying (CEQ2PSK) is proposed. It uses appropriate hard decisions; yet, it achieves optimum probability of bit error performance, unlike the suboptimum detector of Saha and Birdsall. This optimum performance is verified through Monte Carlo computer simulations. Additionally, a more correct expression is given for the probability of bit error performance for CEQ2PSK, which gives the gain over nonconstant Q2PSK as 1.44 dB, rather than the previously published value of 1.76 dB.