A novel direction of arrival (DOA) estimation method in compressed sensing (CS) is presented, in which DOA estimation is considered as the joint sparse recovery from multiple measurement vectors (MMV). The proposed method is obtained by minimizing the modified-based covariance matching criterion, which is acquired by adding penalties according to the regularization method. This minimization pro...

This paper presents a theoretical study on an optimum SAR-GMTI mode that exploits the flexible programmability of modern phased array radars such as RADARSAT-2 (R2) and TerraSAR-X. One major challenge for SAR-GMTI is the considerable re-positioning error owing to large stand-off ranges. A new GMTI mode is proposed that combines the two concepts of antenna tapering with aperture switching betwee...

This paper discusses the propagation delay estimation problem for DS-CDM4 based on an adaptive antenna array whzch can suppress interfering signals. The tap weights of the adaptzve beamformer are controlled by two adaptive algorithms such as direct matrzx inver.won (DM7) and linearly constrained minimum variance (LCW). The large sample maximum likelihood (ZSML) estimator is applied to the beamf...

In this paper, challenges regarding the provision of channel state information (CSI) and carrier frequency synchronization for multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems with null subcarriers are addressed. We propose a novel maximum likelihood (ML) based scheme that estimates the aggregate effects of the channel and carrier frequency offset (C...

Most of the available localization algorithms require pair-wise ranging between the nodes. The more accurate the ranging, the more precise the localization. In this paper, the problem of accurate ranging between sensor nodes in an underwater environment is considered. It is assumed that the underwater medium is composed of layers with an isogradient depth-dependent sound speed profile (SSP). Fo...

The problem of joint direction of arrival (DOA) and frequency estimation is considered in this paper. A new method is proposed based on the signal-dependent multistage wiener filter (MWF). Compared with the classical subspace-based joint DOA and frequency estimators, the proposed method has two major advantages: (1) it provides a robust performance in the presence of colored noise; (2) it does ...

The low-frequency natural response of conducting, permeable targets is investigated. We demonstrate that the source-free response is characterized by a sum of nearly purely damped exponentials, with the damping constants strongly dependent on the target shape, conductivity, and permeability, thereby representing a potential tool for pulsed electromagnetic induction (EMI) identification (discrim...

Localization is essential for wireless sensor networks (WSNs). It is to determine the positions of sensor nodes based on incomplete mutual distance measurements. In this paper, to measure the accuracy of localization algorithms, a ranging error model for time of arrival (TOA) estimation is given, and the Cramer–Rao Bound (CRB) for the model is derived. Then an algorithm is proposed to deal with...

In this paper, a new low-complexity method for two-dimensional (2D) direction-of-arrival (DOA) estimation is proposed. Based on a cross-correlation matrix formed from the L-shaped array, the proposed algorithm obtains the automatic pairing elevation and azimuth angles without eigendecomposition, which can avoid high computational cost. In addition, the cross-correlation matrix eliminates the ef...

Two-dimensional multiple signal classification (MUSIC) algorithm based on polarization sensitive array (PSA) has excellent performance. However, it suffers a high computational complexity due to a multitude of complex operations. In this paper, we propose a real-valued two-dimensional MUSIC algorithm based on conjugate centrosymmetric signal model, which is applicable to arbitrary centrosymmetr...