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Exploiting the received signals, which are usually not employed in the traditional OTH radar for ionospheric parameter estimation, we study joint estimation of target and ionospheric parameters for multiple-input multiple-output skywave OTH (MIMO-OTH) radar. We employ a parabolic layer model to characterize the ionospheric distortions. We model the target and ionospheric parameters as deterministic...
The noise background of small aperture sensor array is spatial color noise for underwater sonar detection system. A super-directive beamform in frequency domain (FSD) method is proposed to solve the problem that the array gain of super-directive beamform cannot reach maximum when there exists error in the estimated noise matrix under spatial color noise background. The wideband received data are divided...
We consider a joint decentralized detection and estimation problem in which a number of sensor nodes collaborate to detect and estimate an unknown deterministic vector signal. To cope with the power/bandwidth constraints inherent in wireless sensor networks (WSNs), each sensor compresses its observations using a linear precoder. The compressed messages are transmitted to the fusion center (FC), where...
Inverse Synthetic Aperture Radar (ISAR) Imaging with Low Signal to Noise Ratio (SNR) is one of difficulties in radar target detection. A new technique for ISAR motion compensation with low SNR is presented. For the range alignment, the cross-correlation method based on the exponential weight accumulative gliding window is applied to achieve the coarse range alignment. The precise range alignment within...
The up-to-date researches focused on compressive sensing (CS) have indicated that a CS-based system could be very sensitive to signal noise which contaminates the input signal prior to measurement. In this paper, it is demonstrated that the SNR loss of the recovered signal can be estimated by the subsampling rate. The conditions based on which the proposed estimator is applied are theoretical analyzed...
This paper analyzes the problem of detecting a monochromatic plane wave with unknown amplitude, phase, temporal frequency and direction of arrival (DOA) in complex white Gaussian noise with unknown variance. The uniformly-most-powerful-invariant (UMPI) test is derived by using statistical invariance principle but doesn't exist unless the signal-to-noise ratio (SNR) is known. However, it provides performance...
This paper proposes an adaptive β-order Minimum-Mean-Square-Error (MMSE) estimator for speech enhancement using super-Gaussian speech model (β-SG-MMSE). The spectral amplitude of clean speech is estimated by MMSE estimator under the assumption that the DFT coefficients of clean speech are modeled by super-Gaussian distribution and the DFT coefficients of noise signal are modeled by Gaussian distribution...
This paper is concerned with the performance of energy detection for spectrum sensing in cognitive radio. Both fading and shadowing are considered by assuming a Nakagami-lognormal composite channel model. Based on a newly-derived exponential integral representation for the generalized Marcum Q-function, performance analysis of energy detection is formulated as a unified moment generating function...
Mechanical Relay (McR) is an architecture to enable data communications, where transmission delay and intermittent service are tolerated. Since each source and destination user uploads/downloads data when McRs are located in transmission range, we obtain more significant sum-throughput gain than fixed/no relay networks even if some packet delay might be burden for delay-sensitive cases. In this paper,...
In this paper, a novel distributed concatenated Alamouti code is devised for a one-way relaying network consisting of two end nodes with each having a single antenna and one relay node equipped with two antennas. With the aid of the newly developed uniquely-factorable constellation pair (UFCP) generated from square quadrature amplitude modulation (QAM) constellation and by jointly processing the noisy...
This paper presents a novel speech enhancement algorithm based on β-order GARCH (Generalized Auto-regressive Conditional Heteroscedasticity) model. The speech signal is modeled as β-order GARCH process, and the a priori SNR is estimated effectively. The noisy signal is divided into several critical bands, and then the value of order β is updated adaptively according to the signal-to-noise ratios in...
Power minimization is a traditional method for interference suppression in satellite navigation systems. It works when the interferences are much stronger than the desired signals and noise, and its main advantage is that the direction of arrival (DOA) information of the desired signals is not required. In this paper, a new method for suppressing strong interferences for satellite navigation based...
Compressive sensing (CS) is applied to enable real time direction of arrival (DoA) estimation in a wireless array sensor network by significantly reduce the amount of sensor data that needs to be transmitted over wireless channels. This is accomplished by (i) random sampling of data samples collected at sensor arrays, and (ii) transmitting only the sign-bit of the data samples over wireless channels...
In this paper, we propose a time-multiplexed-superimposed training (TMST) scheme and investigate the individual channel tracking problem in amplify-and-forward one-way relay network (OWRN) under doubly selective channel scenario. The individual channels from source to relay and from relay to destination are approximated by finited number of coefficient through the complex-exponential basis-expansion-model...
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