Kenneth Wing-Kin Lui

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—Finding the positions of nodes in an ad hoc wireless sensor network (WSN) with the use of the incomplete and noisy distance measurements between nodes as well as anchor position information is currently an important and challenging research topic. However, most WSN localization studies have considered that the anchor positions and the signal propagation(More)
—The sum capacity of the one-sided parallel Gaussian interference channel is shown to be a concave function of user powers. Exploiting the inherent structure of the problem, we construct a numerical algorithm to compute it. Two suboptimal schemes are compared with the capacity-achieving scheme. One of the suboptimal schemes, namely iterative wa-terfilling,(More)
A popular strategy for source localization is to utilize the measured differences in arrival times of the source signal at multiple pairs of receivers. Most of the time-difference-of-arrival (TDOA) based algorithms in the literature assume that the signal transmission speed is known which is valid for in-air propagation. However, for in-solid scenarios such(More)
—In this letter, the problem of adaptive tracking the amplitude and phase of a noisy sinusoid with known frequency is addressed. Based on approximating the recursive Gauss–Newton approach , two computationally simple algorithms, which provide direct parameter estimates, are devised and analyzed. Simulation results show that the proposed methods can attain(More)
A two-stage autocorrelation approach is proposed for single-tone frequency estimation of a real sinusoid in white noise. In the first stage, we transform the received data to another noisy sinusoidal sequence of same frequency via an autocorrelation procedure. Autocorrelation functions of the converted sequence are then employed for frequency estimation in(More)
A conventional approach for source localization is to utilize time delay measurements of the emitted signal received at an array of sensors. The time delay information is then employed to construct a set of hyperbolic equations from which the target position can be determined. In this paper, we utilize semi-definite programming (SDP) technique to derive a(More)
Extraction of spectral information from landsat TM data and merger with SPOT panchromatic im-agery—A contribution to the study of geological structures, " ISPRS J. The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis, " Proc. brain activity pattern analysis in time-frequency domain with nonneg-ative(More)
Index Terms time-difference-of-arrival, optimum array geometry, source localization Abstract Finding the position of a radiative source based on time-difference-of-arrival (TDOA) measurements from spatially separated receivers has important applications in sonar, radar, mobile communications and sensor networks. Each TDOA defines a hyperbolic locus on which(More)
The problem of node localization in a wireless sensor network (WSN) with the use of the incomplete and noisy distance measurements between nodes as well as anchor position information is currently an an important yet challenging research topic. Most WSN localization studies at present have assumed that the anchor positions are perfectly known which is not(More)