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Analog-to-information converters and Compressed Sampling (CS) sensor front-ends try to only extract the relevant, information-bearing elements of an incoming data stream. Information extraction and recognition tasks can run directly on the compressed data stream without needing full signal reconstruction. The accuracy of the extracted information or classification is strongly determined by the front-end...
Identifying and detecting the unknown abnormal sparse signal has become an important issue for distributed networks. In this paper, we proposed a new detection scheme based on convex optimization for wireless sensor networks. Under the Neyman-Pearson testing framework, the detection scheme first estimates the unknown signal by employing the convex optimization at the fusion center. Then the sensor...
Data-driven respiratory gating techniques in cardiac PET extract respiratory motion signal from the PET data to guide respiratory gating and motion estimation. However, the influence of the quality of the list-mode data including the uptake ratio between the myocardium and background and the detected count level on its performance has never been studied thoroughly. In this project, list-mode PET data...
The objective of this work is to embed watermark information into digital audio data as the deterioration of sound quality is not perceivable to human ears. Hence, we consider that watermark information is embedded in the consonance to melody line or bass line. Generally, unison, octave, perfect fifth and perfect fourth are called consonance and human ears can hardly feel annoyed for consonance. Hence,...
Compressive sensing (CS) creates a new framework of signal reconstruction from a smaller set of incoherent projection compared with the traditional Nyquist-rate sampling theory. Recently, it has been shown that CS can solve some signal processing problems given incoherent measurements without reconstructing signals. Moreover, the number of measurements for most compressive signal processing application...
How to determine the stopping mechanism and parameters is the key in the anisotropic diffusion filtering of images. This paper introduces image structures similarity (SSIM) to time scale estimation based on anisotropic diffusion. It proposes a novel estimation method of the optimal diffusion time scale by SSIM. The method correlates well with the judgment of human observers and needs not to estimate...
In this paper, a new approach of blind estimation of subcarrier number based on multiple signal classification (MUSIC) algorithm is proposed for MB-OFDM ultra-wide band (UWB) communications system. The proposed eigenvalue-construct method only using signal autocorrelation of orthogonal frequency-division multiplexing (OFDM) symbols estimates the number of subcarriers. The computer simulations show...
Quasi-Monte Carlo (QMC)-based particle filters can obtain more accurate estimation than the general particle filters, with formidable computational complexity, however. Spatial-domain multiresolutional particle filters are more efficient by reducing the number of particles, but unevenly samples may cause estimation error. Aiming at these, we combine QMC numerical technique and multiresolutional methodology...
A feedback mechanism of the Page test is proposed in this paper. From the aspects of SNR estimation on square output of the matched filter, normalization, and the gate calculation, the information feedback flow is discussed. A new one-threshold Page test and processing flow that can effectively distinguish between target and interferences by cumulating change process adequately are also proposed....
In hybrid automatic repeat request (HARQ) process, a retransmission occurs on the condition that the first transmission failed. Multiple received packets are combined for detection at the receiver. Equivalent noise after combining is not additive Gaussian white noise and not independent on the transmitted signal. Unfortunately, the assumption of zero-mean-Gaussian and independent noise after combining...
We consider the problem of estimating the central direction of arrival (DOA) of multiple coherently distributed sources. This problem is encountered due to the presence of local scatters in the vicinity of a transmitter or due to signals propagating through a random inhomogeneous medium. Since the integral steering vector of coherently distributed source can be deduced to be a Schur-Hadamard product...
Estimation of the instantaneous frequency (IF) of nonlinear FM signals with additive Gaussian noise is considered. An algorithm for the IF estimation is proposed based on Wigner-Ville distribution (WVD) maxima and local singular value decomposition (SVD).Simulation result shows that the proposed method is valid for nonlinear FM signals.
Focusing on the packet acquisition of UWB non-coherent system, a novel scheme is proposed in this article, which combines frame synchronization with signal acquisition and bit error probability (BEP) optimization together. Online signal to noise ratio (SNR) estimation is made for minimize BEP function after signal acquisition, combined with the search of optimal length of integral window. Experiments...
In this paper, an algorithm reprocessing of the power spectrum density (RPSD) is proposed to detect and estimate the PN code's period of the multipath direct sequence spread spectrum (DS/SS) signal in low SNR, which develops the previous processing method based on the single path environment. It can solve the difficult problem of PN code's period detection and estimation in multipath environment....
In this paper, theoretical limits on estimation of respiration rates via pulse-based ultra-wideband (UWB) signals are studied in the presence of prior information about respiration related signal parameters. First, a generalized Cramer-Rao lower bound (G-CRLB) expression is derived, and then simplified versions of the bound are obtained for sinusoidal displacement functions. In addition to the derivation...
This paper proposes a new I/Q imbalance estimation algorithm for multiband orthogonal frequency division multiplexing (MB-OFDM) based ultra-wideband (UWB) systems. The proposed algorithm is highly effective for the UWB channels with strong frequency selectivity in the presence of carrier frequency offset (CFO). In order to estimate I/Q imbalance, the 2nd-order moments of received signal are analyzed,...
We consider a problem of significant practical importance, namely, the reconstruction of a low-rank data matrix from a small subset of its entries. This problem appears in many areas such as collaborative filtering, computer vision and wireless sensor networks. In this paper, we focus on the matrix completion problem in the case when the observed samples are corrupted by noise. We compare the performance...
In this paper, we consider decentralized estimation of a noise-corrupted deterministic parameter in wireless sensor networks with the aid of relay. We propose a new relay-aided decentralized estimation scheme by which relay collects the overheard messages from sensors, computes a local message, and then sends it to a destination. Besides, we develop the sensor selection policies to select the most...
Modelling of interferometric signals related to tear film surface quality is considered. In the context of tear film surface quality estimation in normal healthy eyes, two clinical parameters are of interest: the build-up time, and the average interblink surface quality. The former is closely related to the signal derivative while the latter to the signal itself. Polynomial signal models, chosen for...
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