The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Modern wireless communication raise the demand for higher spectral efficiency, faster-than-Nyquist (FTN) signaling is able to increase transmission rate without expanding signaling bandwidth. In this paper, we develop a graph-based iterative FTN detector in the presence of phase noise (PHN). Wiener process is employed to model the time evolution of nonstationary channel phase. The colored noise imposed...
It is of enormous significance to detect abnormal brains automatically. This paper develops an efficient pathological brain detection system based on the artificial intelligence method. We first extract brain edges by a Canny edge detector. Next, we estimated the fractal dimension using box counting method with grid sizes of 1, 2, 4, 8, and 16, respectively. Afterward, we employed the single-hidden...
In this paper, we propose an adaptive combining multi-branch frequency-domain detector (ACMFD) for amplify-and-forward (AF) underwater acoustic cooperative communication. In contrast to the existing methods, the proposed detector can adaptively combine the received signals from different nodes at destination, and don't need the assumption that full and perfect channel state information (CSI) of all...
This paper presents a statistical approach to the formation of a complete set of “meaningful contours” conformal to human visual perception, characterized by preserving both illusory edge pixels and their corresponding physical edge pixels through alignment interpretation. The method mainly consists of two stages: (i) learning alignment significance (LAS) based on the evaluation of orientations neighboring...
This paper presents a novel approach called PEPA (Perceptual Edges Preservation Algorithm) which enables computing machines to mimic the human vision capability in perceiving meaningful objects in an input scene, characterized in that the preserved edges are conformal to human vision perception. The approach mainly comprises three stages: (1) applying linear and nonlinear filtering to mimic the capability...
To improve the accuracy of measurement and response speed, a phase-sensitive detection (PSD) theory based micro-capacitance detect circuit is designed. In the front of circuit, the DDS chip generate a sinusoidal signal to excite the capacitor under test, the measured signal and reference signal enter into phase-sensitive detector after the capacitance/voltage convertion. After lock-in amplify and...
In this paper, the acquisition performances of different detectors are investigated and evaluated for frame acquisition in DVB-S2 system. Mean acquisition time in both single-dwell and multi-dwell procedures are derived based on a Markov chain model. Since it is quite complicated to analyze some parameters in close formula, a semi-analytical method is adopted to simplify the analysis. Performance...
In this paper, based on analyzing the detector characteristics of modified Gardner (mGA) timing error detector examined before, an extended non-carrier-blind detector is proposed for quadratic phase shift keying (QPSK) signals. The timing jitter performance of new detector is about 2dB-10dB better than that of mGA at low and high signal-to-noise ratio (SNR) respectively. However, this advantage is...
In this paper, we consider the effect of different rules of symbol decision on the performance of decision-directed synchronizers for LDPC-coded systems. Different from the conventional hard symbol decision based on the Maximum-A- Posteriori (MAP) criterion, soft symbol decision can be considered as the Minimum-Mean-Square-Error (MMSE) estimation of the transmitted symbol. By whether or not the coding...
For the symbol timing recovery techniques which are susceptible to carrier phase offset, clockless phase recovery is necessary in advance. In this paper, we propose a clockless nondata-aided (NDA) feedback phase error detector (PED) for M-ary phase-shift keying (MPSK) signal. Its derivation is given based on maximum likelihood (ML) criterion. The clockless NDA (Mthpower)PED can also be generalized...
In this paper, based on analyzing some existing phase lock detectors for quadratic phase-shift keying (QPSK),we propose a novel method of estimating the signal-to-noise ratio (SNR) operating with the lock metric value of classical Mth-power (M=4) phase lock detector. The proposed lock detector-based SNR estimator can perform better than the conventional SNR estimator in terms of mean estimated value...
An improved data-aided (DA) frequency error detector (FED) and a frequency lock detector are proposed under large frequency offset for Digital Video Broadcasting Satellite Second Generation (DVB-S2) system. Computer simulations results show that the proposed error detector can increase the frequency acquisition range and decrease the acquisition time without complexity increase. Its closed-loop normalized...
In this paper, we propose a new feedback decision-directed (FB-DD) phase error detector for quadratic phase-shift keying (QPSK) signal and a self-normalizing FB-DD detector for M-PSK signal. The self-normalizing detector can be used in the hybrid carrier recovery loop as discussed by Linn, while its open loop characteristic is independent of the imperfection of automatic gain control (AGC). Moreover,...
The principle and configuration of the signal processing circuit for 480times6 infrared detector is studied in this paper. The designed circuit consists of the analog processing circuit, the differential input analog to digital converting circuit and the digital data processing circuit. The analog processing circuit, including the impedance transformation circuit, the single-ended to differential...
An efficient algorithm for facial features extractions is proposed. The facial features we extracted are the edges of two eyes, nose and mouth. The algorithm is based on an improved Gabor wavelets edge detector to detect the face region and facial features regions. The experimental results show that the proposed method is robust against facial expression, illumination, and can be also effect if the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.