One important application in the field of adaptive antenna array processing used in recent wireless communications systems, such as cognitive radio applications, is the direction of arrival (DoA) estimation. The exist...
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ISBN:
(纸本)9781509064779
One important application in the field of adaptive antenna array processing used in recent wireless communications systems, such as cognitive radio applications, is the direction of arrival (DoA) estimation. The existing works suggest that the N-x x N-y, two dimensional (2 - D) antenna array is almost surely able to recover up to [N-x/2] [N-y/2] two dimensional (2 - D) DoA. In this paper, a new 2 - D (azimuth and elevation) DoA estimation method using a minimum sparse ruler based rectangulararray of antenna is evaluated. The minimal sparse ruler is used to determine which antennas that have to be deactivated and which antennas that should be remain active. Therefore, it is possible to deactivate some antennas in the uniform rectangular array (URA) leading to a sparse rectangulararray (SpRA). While minimizing the reduction in the quality of the resulting DoA estimation with SpRA, the selection and averaging procedure are adopted to tackle these elements. This approach is possible for uncorrelated sources as the covariance matrix of the impinging signals on the URA contains redundant elements. The selection and averaging procedures are adopted to tackle these elements. These steps are followed by the execution of the MUSIC algorithm to compute the 2-D DoA estimates. The simulation study shows that it is possible to employ only 25-antennas in SpRA in order to estimate the azimuth (phi) and the elevation (theta) angles of up to 19 sources. The combinations of (phi) and (theta) is drawn from the range of 0 degrees <= phi <= 180 degrees and 0(0) <= theta <= 90 degrees. The separation in azimuth and elevation angles between sources is at least 10 degrees.
In this paper, joint frequency and 2-D direction of arrival (DOA) estimation at sub-Nyquist sampling rates of a multi-band signal (MBS) comprising of P disjoint narrowband signals is considered. Beginning with a stand...
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ISBN:
(纸本)9780992862671
In this paper, joint frequency and 2-D direction of arrival (DOA) estimation at sub-Nyquist sampling rates of a multi-band signal (MBS) comprising of P disjoint narrowband signals is considered. Beginning with a standard uniform rectangular array (URA) consisting of M = M-x x M-y sensors, this paper proposes a simpler modification by adding a N - 1 delay channel network to only one of the sensor. A larger array is then formed by combining the sub-Nyquist sampled outputs of URA and the delay channel network, referred to as the difference space-time (DST) array. Towards estimating the joint frequency and 2-D DOA on this DST array, a new method utilizing the 3-D spatial smoothing for rank enhancement and a subspace algorithm based on ESPRIT is presented. Furthermore, it is shown that an ADC sampling frequency of f(s) >= B suffices, where B is the bandwidth of the narrow-band signal. With the proposed approach, it is shown that O(MN/4) frequencies and their 2-D DOAs can be estimated even when all frequencies alias to the same frequency due to sub-Nyquist sampling. Appropriate simulation results are also presented to corroborate these findings.
A novel two-dimensional (2-D) direct-of-arrival (DOA) and mutual coupling coefficients estimation algorithm for uniform rectangular arrays (URAs) is proposed. A general mutual coupling model is first built based on ba...
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A novel two-dimensional (2-D) direct-of-arrival (DOA) and mutual coupling coefficients estimation algorithm for uniform rectangular arrays (URAs) is proposed. A general mutual coupling model is first built based on banded symmetric Toeplitz matrices, and then it is proved that the steering vector of a URA in the presence of mutual coupling has a similar form to that of a uniform linear array (ULA). The 2-D DOA estimation problem can be solved using the rank-reduction method. With the obtained DOA information, we can further estimate the mutual coupling coefficients. A better performance is achieved by our proposed algorithm than those auxiliary sensor-based ones, as verified by simulation results. (C) 2015 Elsevier B.V. All rights reserved.
In this paper, two receive beamforming techniques (Method 1 and Method 2) are proposed for a mobile station (MS) with multiple antenna arrays in an OFDM-based millimeter-wave (mm-wave) cellular communication system. S...
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In this paper, two receive beamforming techniques (Method 1 and Method 2) are proposed for a mobile station (MS) with multiple antenna arrays in an OFDM-based millimeter-wave (mm-wave) cellular communication system. Since the MS in mm-wave cellular communication requires fast processing due to its frequent movement and rotation, a receive beamforming technique with reduced computation complexity and processing time is proposed in Method 2. Of particular interest, estimation techniques for 2-dimensional (2D) direction-of-arrivals (DoAs) corresponding to each cell ID are proposed for uniform circular arrays (UCAs) and uniform rectangular arrays (URAs). Also, a cell selection technique for MSs with multiple antenna arrays is described that use the candidate cell IDs and parameters estimated for all antenna arrays to provide combining gain in addition to array gain in multipath channels. The proposed beamforming techniques are evaluated by computer simulation using a simple model of a mm-wave cellular communication system with 3-dimensional spatial channel model (3D SCM).
A computationally efficient two-dimensional (2-D) direction-of-arrival (DOA) estimation method for uniform rectangular arrays is presented. A preprocessing transformation matrix is first introduced, which transforms b...
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A computationally efficient two-dimensional (2-D) direction-of-arrival (DOA) estimation method for uniform rectangular arrays is presented. A preprocessing transformation matrix is first introduced, which transforms both the complex-valued covariance matrix and the complex-valued search vector into real-valued ones. Then the 2-D DOA estimation problem is decoupled into two successive real-valued one-dimensional (1-D) DOA estimation problems with real-valued computations only. All these measures lead to significantly reduced computational complexity for the proposed method.
This paper presents the model of satellite planar array, and interference localization via direction of arrival(DOA) estimation. We derive a dimension reduction DOA estimaton algorithm therein. The proposed algorithm,...
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ISBN:
(纸本)9783038353140
This paper presents the model of satellite planar array, and interference localization via direction of arrival(DOA) estimation. We derive a dimension reduction DOA estimaton algorithm therein. The proposed algorithm, which only requires a one-dimensional local searching, can avoid the high computational cost within two-dimensional multiple signal classification (2D-MUSIC) algorithm. We illustrate that the proposed algorithm has better angle estimation performance than estimation method of signal parameters via rotational invariance technique (ESPRIT) algorithm, and has very close angle estimation performance to 2D-MUSIC algorithm. Furthermore, our algorithm requires no extra pairing. Simulation results present the usefulness of our algorithm.
Occurrence of partial discharges (PD) is one of the basic criteria of high voltage devices insulation evaluation. Precise PD source location is crucial for undertaking maintenance of mentioned equipment. This paper co...
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ISBN:
(纸本)9781479966134
Occurrence of partial discharges (PD) is one of the basic criteria of high voltage devices insulation evaluation. Precise PD source location is crucial for undertaking maintenance of mentioned equipment. This paper concerns the issue of partial discharges sources location using phased rectangulararrays technique and high-resolution direction of arrival estimation technology. In addition to the theoretical assumptions of both techniques, the simulation result, in which an uniform rectangular array (URA) was used for registration of the electromagnetic signals generated by defects in power transformer insulation system, were shown. To estimate the Direction of Arrival (DOA) of electromagnetic signals, that propagate from the discharge-generating defect to the transducer array installed on transformer tank, Minimum Variance Distortionless Response (MVDR) algorithm was chosen. The location of defect was determined using two intersecting lines defined by the DOAs from two URAs. With the ability to locate multisource discharges (even at very low signal to noise ratio - SNR), the adopted solution has advantages over conventional techniques.
A precise model of the array response is required to maintain the performance of direction-of-arrival (DOA) estimation. When modeling errors are present or the sensor environment is time-varying, autocalibration becom...
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A precise model of the array response is required to maintain the performance of direction-of-arrival (DOA) estimation. When modeling errors are present or the sensor environment is time-varying, autocalibration becomes necessary. In this paper, the problem of phase autocalibration for uniform rectangular array (URA) geometries is considered. For the case with a single source, a simple and robust least-squares algorithm for joint 2-D DOA estimation and phase calibration is presented. When performing phase autocalibration with a URA, the phase and DOA parameters cannot be identified together without ambiguity. This problem is discussed and a suitable remedy is suggested. An approximate Cramer-Rao bound and analytical expressions for the mean squared error performance of the proposed estimator are presented. The proposed algorithm for phase autocalibration is extended for the case with multiple sources. The results are evaluated using a representative body of simulations.
The paper proposes a time reversal based uniform rectangular array (TR/URA) system for joint estimation of azimuth and elevation of a stationary target. For target localization in a rich scattering environment, conven...
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ISBN:
(纸本)9781467301831
The paper proposes a time reversal based uniform rectangular array (TR/URA) system for joint estimation of azimuth and elevation of a stationary target. For target localization in a rich scattering environment, conventional radars fail due to interference from multipath signal reflections. The TR/URA system uses multipath to its advantage by utilizing the energy constructively from all paths. To quantify its performance, we derive the Cramer-Rao lower bounds (CRLB) for both the conventional and TR/URA systems. In both our analytical comparisons based on the CRLBs and Monte Carlo simulations, the TR/URA system outperforms its conventional counterpart by a factor of up to 10dB in SNRs ranging from -25dB to 0dB.
Many imaging arrays have a regular sensor conguration. This regularity can be exploited for self-calibration of the array. In this paper, we introduce a new self-calibration method for regular arrays based on weighted...
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ISBN:
(纸本)9781467310680
Many imaging arrays have a regular sensor conguration. This regularity can be exploited for self-calibration of the array. In this paper, we introduce a new self-calibration method for regular arrays based on weighted alternating least squares (WALS) optimization that appears to be statistically efficient and does not impose requirements on the source structure or on pre-calibration of the array. We show results from Monte Carlo simulations indicating that the proposed method already attains the Cramer-Rao bound (CRB) at very low SNR and produces unbiased results. Our simulations also indicate that the approach most commonly used in the literature does not attain the CRB at high SNR and produces biased results at low SNR.
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