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.
In this paper,we propose a sparse Baysesian learning (SBL) based approach for the DOA estimation in the presence of coherent sources. First, the difference technique is used to enhance the input SNR. Then, we construct a virtual array manifold to eliminate the cross-term effect between each coherent group, after eigenvalue decomposition (EVD) of the difference covariance matrix, reduce the dimension...
The two-dimensional (2-D) direction-of-arrival (DOA) estimating for non-circular signals in highly real-time situation is addressed. A new algorithm using a single snapshot for 2-D DOA estimating is proposed. Based on the dual parallel uniform linear array (ULA), three equivalent rotationally invariant covariance matrices are constructed using the single snapshot, which are evaluated to generate the...
The cast austenitic stainless steel (CASS) is hard to be detected using general ultrasonic methods on account of the low signal to noise ratio (SNR) caused by coarse-grained structure. A numerical model based on electron backscattered diffraction (EBSD) was established to simulate the phased array ultrasonic imaging of CASS. Aiming to enhance SNR, the phase coherence imaging (PCI) technique was implemented...
Direction of Arrival (DOA) estimation implies estimating the direction concerning angles of arrival of the received signals by an array of elements. This paper presents a review to a comparative analysis of several DOA estimation algorithms broadly classified into Beamforming (Classical & Capon's) and Subspace-based techniques (Multiple Signal Classification (MUSIC), Minimum Norm and Root-MUSIC)...
A compact range wireless access system in the 60 GHz-band has been proposed for multi-Gb/s data transfer. A prototype GATE (Gigabit Access Transponder Equipment) was made to evaluate the coverage as well as the system performance of received power, bit-error rate (BER) and signal-to-noise ratio. Originally, the double-layer corporate-feed waveguide slot arrays with different number of elements were...
Ocean ambient noise mainly includes uncorrelated noise and correlated noise. The uncorrelated noise only affects the diagonal elements in the noise covariance matrix, and it can be suppressed by subtracting a value on the diagonal elements. Utilizing this feature, a high array-gain beamforming based on diagonal reducing is presented. Meanwhile, the robustness becomes poor. So, the array weight norm...
Passive sources localization in the presence of strong interferences is generally a difficult problem. A sparse-representation-based adaptive interference suppression (SRAIS) method is proposed in this paper for interference suppression and bearing estimation, which can reduce the power loss of the TOI signal and have more accurate direction-of-arrival (DOA) estimation, especially when the input powers...
Competitive advantage of a firm is usually reflected through its superiority in production resources and performance outcomes. In order to achieve high performance (e.g., productivity) and significantly improve product quality, major US industries have promoted and implemented Robust Design (RD) techniques during the last decade. RD is a cost-effective procedure for determining the optimal settings...
Estimation of a signal transmitted through a communication channel usually involves channel identification. This scenario can be modeled as random parameter estimation in the presence of unknown deterministic parameter. In this paper, we address the question of how accurately one can estimate a random signal intercepted by an array of sensors, subject to an unknown deterministic array response. The...
The reiterative super-resolution (RISR) algorithm was previously developed to enable adaptive beamforming with as few as one time snapshot, is robust to temporally correlated signals, and accounts for array calibration errors. Here a gain-constrained version (denoted GC-RISR) is derived followed by a partially-constrained version (PC-RISR). It is shown that an interesting trait of the latter is spatial...
High-resolution direction of arrival (DOA) estimation has always been an issue in signal processing field. Most of conventional methods such as Multiple Signal Classification (MUSIC), suffer from lack of resolvability in low signal to noise ratio (SNR) or small number of snapshots whereas computation cost of new methods are considerable. The Compressive MUSIC (CS-MUSIC) algorithm deals with joint...
The usage of antenna arrays brought innumerable benefits to radio systems in the last decades. Arrays can have multidimensional structures that can be exploited to achieve superior performance and lower complexity. However, the literature has not explored yet all the advantages arising from these features. This paper uses tensors to provide a method to design efficient beamformers for multidimensional...
The Direction of Arrival (DoA) estimation of signals impinging on a failed antenna array is approached as an optimization problem and solved by using particle swarm optimization (PSO) technique with single snapshot. The performance and usefulness of this algorithm is analyzed under different failure scenarios and also in different noisy environment. In this paper we have made a study on the tolerance...
Since a nested phased array cannot directly estimate the range of targets due to range ambiguity, this paper proposes a nested array with diverse time-delayers for target range and angle estimation. The essence is to construct a new array structure by systematically nesting two uniform linear arrays through diverse time-delays which yields a range-dependent receiving array beampattern. Using second-order...
Future handsets are characterized by their small size which limits the number of antennas and the spacing between them. This paper mainly focuses on Direction-of-Arrival (DOA) estimation in Multiple-Input-Multiple-Output (MIMO) systems based on Compressive Sensing (CS) with practical limitations. The main objective is to strike an optimal balance between complexity and accuracy. A comparison between...
A 60GHz-band compact-range wireless access system using a large array antenna can provide an uniform signal reception zone (less than 14 m distance from the antenna) and an almost multipath-free propagation environment. To evaluate the system performance, a wireless communication system for demonstration is constructed and the bit error rate (BER) and the signal-to-interference-plus-noise ratio (SINR)...
It is shown that implementation of the method of space-time division multiple access with the individual space-time processing of subscriber stations signals which is reduced to the use of group elements of adaptive antenna array and the establishment of parallel procedures of assessing values of vector of weighting coefficients on the number of simultaneously working stations.
In this paper, we derive for the first time analytical expressions for the stochastic Cramér- Rao lower bound (CRLB or CRB) of the angular parameters (central DOAs and angular spreads) estimates from incoherently distributed (ID) signals generated by noncircular sources. The new CRBs of the angular parameters are compared to those obtained from circular ID signals. The CRB of the central DOAs, however,...
We discuss the SINR-maximization problem for analog receive beamforming with finite resolution phase shifters and amplifiers. This discrete optimization problem can be globally solved by means of branch-and-bound. The performance of the algorithm depends on the quality of bounds for the subproblems which are determined within the branch-and-bound procedure. These subproblems can be generated by a...
In multiple source detection of using an array, the threshold of the generalized likelihood ratio test (GLRT) is only related with the noise power. And the false alarm probability will increase when one signal is present in the sidelobe of beamformer's pattern because of energy leakage. A constant false alarm ratio (CFAR) based multiple-source detection algorithm was proposed in this paper. The detection...
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.