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This work derives new asymptotic Cramer-Rao lower bounds (CRB) for the estimation of multiple pure-tone incident signals' azimuth-elevation arrival-angles, polarization parameters, frequencies, amplitudes, and temporal phases--based on data collected by spatially collocated but orthogonally oriented dipoles and/or loops. The incident sources are pure-tones at distinct, deterministic but unknown frequencies, in contrast to the case of all incident sources at one common known frequency, as has been investigated in the existing research literature on the CRB for diversely-polarized direction-finding. The derived CRBs are closed-form expressions, explicitly in terms of the signal parameters. The new CRBs presented here reveal how a constituent dipole and/or loop's presence and orientation may affect estimation precision, thereby offering guidelines to the system engineer on what dipole(s) and/or loop(s) to include or to omit in constructing the electromagnetic vector-sensor.

Herein derived are the lower and upper bounds for the number of linearly independent (2Q)th-order virtual steering vectors of an array of electromagnetic vector-sensors, with Q being any positive integer over one. These bounds help determine the number of non-Gaussian signals whose directions-of-arrival (DOAs) can be uniquely identified from (2Q)th-order statistics data. The derived lower bounds increase with Q, whereas the derived upper bounds often fall below the maximum number of virtual sensors achievable from (2Q)th-order statistics manipulation. These bounds are independent of the permutation of the (2Q)th-order statistics entries in the higher order cumulant matrix that has a similar algebraic structure of the classical covariance matrix used in the second-order subspace-based direction-finding algorithms.

A new data-dependent zero-memory preprocessing algorithm is proposed to mitigate additive heavy-tail noise and/or shot noise. Each sensor-array snapshot's spatial data vector is adaptively normalized by its infinity-norm. Zero cross-correlation is preserved between the signal-subspace and the noise-space.

A comprehensive and integrative overview (excluding ultrawideband measurements) is given of all the empirical data available from the open literature on various temporal properties of the indoor radiowave communication channel. The concerned frequency range spans over 0.8-8 GHz. Originally, these data were presented in about 70 papers in various journals, at diverse conferences, and in different books. Herein overviewed are the multipaths' amplitude versus arrival delay, the probability of multipath arrival versus arrival delay, the multipath amplitude's temporal correlation, the power delay profile and associated time dispersion parameters (e.g., the RMS delay spread and the mean delay), the coherence bandwidth, and empirically 'tuned' tapped-delay-line models. Supported by the present authors' new analysis, this paper discusses how these channel-fading metrics depend on the indoor radiowave propagation channel's various properties, (e.g., the physical environment, the floor layout, the construction materials, the furnishing's locations and electromagnetic properties) as well as the transmitted signal's carrier-frequency, the transmitting-antenna's location, the receiving-antenna's location, and the receiver's detection amplitude threshold. Index Terms--Communication channels, dispersive channels, fading channels, microwave communication, mobile communication, multipath channels, scatter channels.

This paper presents the open literature's first closed-form explicit expressions of the trivariate joint and marginal distributions of a landmobile cellular wireless communication system's uplink and downlink multipaths' time of arrival and two-dimensional direction of arrival, rigorously derived via thorough mathematics based on a 'geometrical' model of the three-dimensional (3-D) spatial relationships among the mobile station, the scatterers, and the base station. The scatterers are herein modeled to have a uniform 3-D spatial distribution in an aboveground hemisphere with a flat circular base (or alternatively, within a sphere) centered at the mobile. Index Terms--Communication channels, dispersive channels, fading channels, geometric modeling, microwave communication, mobile communication, multipath channels, scatter channels.

The novel analytical expressions for 'blind' space-time beamformer's nonasymptotic output SINR of Wong, Lok, Lehnert, and Zoltowski (WLLZ) are derived. An increase in the number of despread 'I + N' delay subsegments in estimating the 'I + N' despread space-time data-covariance matrix would alleviate the breakdown of WLLZ.

An existing literature gap in deformed towed-array Direction-of Arrival (DOA)-estimation performance analysis is presented. The new hybrid-CRB expressions herein derived are numerically more stable than those in the current literature.

An underwater acoustic eigenstructure ESPRIT-based algorithm is presented, which produces closed-form direction-of-arrival (DOA) estimates using a single vector hydrophone. New Cramer-Rao bounds (CRB) are derived, for vector hydrophone constructions of arrival angle estimates for the incident uncorrelated sinusoidal siggnals corrupted by additive noise.

Research into radio direction finding using identical subarrays on a Cartesian grid is presented. The algorithm presented is shown to improve and simplify the earlier disambiguation procedures published by the authors.

The authors examine novel applications of velocity hydrophones for using in underwater acoustics . Topics include array signal processing, sonar tracking, and estimation of direction of arrival.

A novel sparse array geometry embedding two sizes of spatial invariances is presented for use with a new ESPRIT-based (estimation of signal parameters via rotational invariance techniques) algorithm for aperture extension. The half-wavelength invariance yields unambiguous but high-variance direction cosine estimates to disambiguate low-variance but cyclically ambiguous estimates from the larger invariance. With larger invariance at 60 half-wavelengths, resolution threshold for two closely spaced emitters is reduced by 50 dB and estimation error by 100-fold. Array design formulas are also presented.