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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Philipp Heidenreich Abdelhak M. Zoubir Signal Processing Group Technische Universitat Darmstadt Merckstrasse 25 Darmstadt 64283 Germany

ISBN: (纸本)9781457705380

To maintain the performance of direction-of-arrival (DOA) estimation, an accurate model of the array response is required. In a time-varying sensor environment, this is only possible with autocalibration. For a uniform linear array, there exist algorithms for autocalibration which exploit the Toeplitz structure of the unperturbed spatial covariance matrix. In this paper, we develop an autocalibration method for 2-D DOA estimation with a uniform rectangular array, in which we exploit a Toeplitz-block Toeplitz structure. We present a simple algorithm for gain and phase estimation, discuss ambiguity problems and evaluate the performance using simulations.

关键词： Autocalibration two-dimensional DOA estimation uniform rectangular array

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IRS Element Grouping With Element-Wise Reflection Coefficients

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IEEE WIRELESS COMMUNICATIONS LETTERS 2024年第1期13卷 168-172页

作者： Lee, Seung Joon Kangwon Natl Univ Dept Elect Engn Interdisciplinary Grad Program BIT Med Convergence Chunchon 24341 South Korea Kangwon Natl Univ Kangwon Inst Telecommun & Informat Chunchon 24341 South Korea

To reduce the overheads of channel estimation and beamforming caused by a large number of intelligent reflecting surface (IRS) elements, a strategy of grouping the IRS elements, in which the same reflection coefficient is shared by all IRS elements within a group, has been used. However, this approach results in very low beam gains at specific directional angles of a channel. To address this issue, we propose a novel scheme that employs a variation pattern of the reflection coefficients within a group. The patterns are designed to differ among the groups, while being fixed regardless of a dynamic channel. We present several sets of patterns that increase the minimized beam gain over the directional angles of a channel and enhance the worst-case performance metrics such as the outage capacity and coverage probability. Some of the pattern sets are generated via heuristic methods, while others are crafted using a systematic iterative sub-optimization technique. Numerical examples demonstrate that the proposed scheme outperforms the conventional method in terms of the outage capacity.

关键词： Grouping intelligent reflecting surface max-min optimization outage capacity reconfigurable intelligent surface uniform rectangular array

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Hierarchical Beamforming for Broadcast Channels

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IEEE COMMUNICATIONS LETTERS 2024年第2期28卷 387-391页

作者： Du, Cheng Li, Fengjie Jiang, Yi Fudan Univ Sch Informat Sci & Technol Dept Commun Sci & Engn Key Lab Informat Sci Electromagnet Waves MoE Shanghai 200433 Peoples R China Fudan Univ Dept Commun Sci & Engn Shanghai 200433 Peoples R China SOTAC Technol Co Ltd Shanghai 201100 Peoples R China

For massive multi-input multi-output (mMIMO) cellular communications, the conventional discrete Fourier transform (DFT) based beamforming yields narrow beams of high directional gain, but it usually requires too many time slots for sweeping the beams to broadcast common messages. To reduce the time of beam sweeping while maintaining sufficient beamforming gain, this letter proposes a hierarchical beamforming (HierBF) scheme. By partitioning a large uniform rectangular array (URA) into multiple sub-URAs, first we apply the omnidirectional beamforming (OBF) to each sub-URA to transform it into a virtual high-power antenna, thus, the large URA is virtually transformed into a smaller array;second we apply the DFT codebook on the smaller virtual array to obtain wider beams, thus, the beam sweeping can be completed in fewer time slots. The HierBF scheme can accommodate to more flexible antenna array sizes than a similar technique termed array-size invariant (ASI). Besides, the HierBF scheme has a complexity of O(1) , and can be implemented using an analog phase shifter network (PSN) with a coarse phase resolution.

关键词： array signal processing Antenna arrays Discrete Fourier transforms Slot antennas Autocorrelation Structural beams Signal resolution Hierarchical beamforming Golay complementary matrices uniform rectangular array

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DOA estimation of multipath signals in the presence of gain-phase errors using an auxiliary source

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IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING 2019年第7期14卷 1114-1121页

作者： Wang, Zhangsheng Xie, Wei Wan, Qun Univ Elect Sci & Technol China Dept Elect Engn Chengdu 611731 Sichuan Peoples R China Southwest China Inst Elect Technol Dept Aerosp Chengdu 610036 Sichuan Peoples R China

In this paper, we address the problem of direction-of-arrival (DOA) estimation of multipath signals in the presence of gain-phase uncertainties using an auxiliary source (AS) with uniform rectangular array. Based on the assumption that the waveform of the AS is a known prior, and the signal of the AS impinges on the array without multipath propagation, a two-step algorithm is proposed to estimate the DOAs along with the fading coefficients and gain-phase errors. First, a coarse estimation is obtained by extending the traditional spatial smoothing-based ESPRIT algorithm. Second, in order to overcome the performance deterioration due to a reduction of the effective array aperture, an alternate iterative algorithm is proposed. Meanwhile, the relevant stochastic Cramer-Rao bound (CRB) is also derived. Simulation results show that the proposed method is capable of approaching the stochastic CRB when the signal-noise ratio (SNR) of the AS is large enough and is greater than the SNR of the unknown source. (c) 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

关键词： direction-of-arrival estimation uniform rectangular array multipath propagation coherent signals sensor gain-phase uncertainties

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A Novel 2D Off-Grid DOA Estimation Method Based on Compressive Sensing and Least Square Optimization

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IEEE ACCESS 2019年 7卷 113596-113604页

作者： Yu, Qiuze Lei, Zhen Hu, Haibo An, Jiachun Chen, Wen Wuhan Univ Sch Elect Informat Wuhan 430072 Hubei Peoples R China Wuhan Univ Chinese Antarctic Ctr Surveying & Mapping Wuhan 430079 Hubei Peoples R China Shanghai Inst Spaceflight Control Technol Shanghai Key Lab Aerosp Intelligent Control Techn Shanghai 200240 Peoples R China

For two-dimensional (2D) direction of arrival (DOA) estimation in a uniform rectangular array (URA), the conventional method converts the 2D problem into a one-dimensional (1D) problem;however, the computational complexity is high, and the accuracy is limited by the grid interval. To address this issue, based on sparse representation theory and a separable observation model (SPM), this paper presents a novel off-grid-framework-based 2D DOA estimation approach by designing a modified 2D off-grid model and a solution for the multisnapshot case in the SPM. The proposed algorithm can be divided into two stages. In the first stage, we use a matching pursuit and focal underdetermined system solver (MFOCUSS) algorithm to quickly identify the candidate or potential areas where the true sources may exist. In the second stage, the candidate areas obtained in the first stage are regarded as the initialization. Then, for a specific source, we regard other sources as interference. By using an alternating descent method, we can obtain accurate DOAs. Moreover, based on the equivalence of time delay and spatial spacing, a 2D off-grid method for multisnapshot cases is proposed in this paper. Numerical simulations demonstrate the effectiveness and efficiency of the proposed algorithm.

关键词： Compressive sensing off-grid model DOA uniform rectangular array sparse signal reconstruction

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Autocorrelation Complementary Matrices 53

Autocorrelation Complementary Matrices

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53rd Asilomar Conference on Signals, Systems, and Computers (ACSSC)

作者： Jiang, Yi Li, Fengjie Wang, Xin Li, Jian Fudan Univ Dept Commun Sci & Engn Shanghai Inst Adv Commun & Data Sci Shanghai Peoples R China Univ Florida Dept Elect & Comp Engn Gainesville FL USA

ISBN: (纸本)9781728143002

This paper studies autocorrelation complementary matrices (ACM), a set of N matrices of size M x L whose two-dimensional autocorrelations add to a two-dimensional deltafunction, which we refer to as a set of (M;N;L)-ACM. The ACM is an extension of the Golay complementary sequences to a matrix form. In addition to an existing approach in the literature to construct the ACM, we show that i) a set of (M;N;L)-complete complementary codes (CCC) is actually a set of (M;N;L)-ACM, and ii) from two pairs of complementary sequences of length M and L we can construct a set of (M;4;L)-ACM (i.e., N = 4). As an application of the ACM, we show how it can be applied to omnidirectional precoding for a multi-input multi-output (MIMO) communication system with a uniform rectangular array (URA).

关键词： complete complementary codes Golay complementary sequences omnidirectional precoding uniform rectangular array

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uniform rectangular TIME REVERSAL arrayS: JOINT AZIMUTH AND ELEVATION ESTIMATION

UNIFORM RECTANGULAR TIME REVERSAL ARRAYS: JOINT AZIMUTH AND ...

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IEEE Statistical Signal Processing Workshop (SSP)

作者： Sajjadieh, Mohammad Asif, Amir York Univ Toronto ON M3J 1P3 Canada

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.

关键词： Time reversal array signal processing uniform rectangular array Joint azimuth and elevation estimation

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Low-Complexity Narrowband Adaptive Beamforming Based on Symmetrically Distributed arrays

Low-Complexity Narrowband Adaptive Beamforming Based on Symm...

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Conference on Wireless Sensing, Localization, and Processing VI

作者： Zhang, Lei Liu, Wei Langley, Richard J. Univ Sheffield Dept Elect & Elect Engn Commun Res Grp Sheffield S1 3JD S Yorkshire England

ISBN: (纸本)9780819486356

Based on the symmetrically distributed array (SDA) structure and the resultant generalised conjugate symmetric property of its optimum weight vector, a transformation matrix is introduced to preprocess the received array data, after which the original complex-valued optimum weight vector is reduced to a real-valued one, so that in the following weight adaptation we can simply remove imaginary part of the weight vector. As a result of this regularization, improved performance is achieved with much lower computational complexity. There is an undetermined phase factor in the transformation matrix and two different cases are studied with beamforming examples provided for each case, supported by simulation results.

关键词： Symmetrically distributed array conjugate symmetric real-valued beamforming transformation uniform linear array uniform rectangular array

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2-D Angle Estimation for MIMO Radar under Coherent Signals 31

2-D Angle Estimation for MIMO Radar under Coherent Signals

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31st Asia-Pacific Microwave Conference (APMC) - Microwave Linking the World

作者： Chen, Yen -Bang Lee, Ju-Hong Natl Taiwan Univ Grad Inst Commun Engn Taipei Taiwan Natl Taiwan Univ Grad Inst Commun Engn Dept Elect Engn Taipei Taiwan

ISBN: (纸本)9781665494182

This paper presents an efficient method to deal with the problem of two-dimensional (2-D) angle estimation for Multiple-Input-Multiple-Output (MIMO) radar in the presence of coherent signals. It is well-known that the performance of angle estimation using MIMO radar systems suffers severe degradation due to coherent signals. This paper presents MNTMR (Minimum Noise Toeplitz Matrix Reconstruction) that selects reference signals that create the least noise component when applying Toeplitz Matrix Reconstruction with reduced computational complexity as compared with the existing methods. Simulation results are also presented for confirmation and comparison.

关键词： Bistatic MIMO Radar Angle Estimation uniform rectangular array Coherent Signals Toeplitz Matrix Reconstruction ESPRIT

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STATISTICALLY OPTIMAL SELF-CALIBRATION OF REGULAR IMAGING arrayS

STATISTICALLY OPTIMAL SELF-CALIBRATION OF REGULAR IMAGING AR...

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20th European Signal Processing Conference (EUSIPCO)

作者： Wijnholds, Stefan J. Noorishad, Parisa Netherlands Inst Radio Astron Res & Dev NL-7990 AA Dwingeloo Netherlands

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.

关键词： autocalibration self-calibration uniform rectangular array uniform linear array redundancy calibration

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