New DOA Estimation Method for Wideband Coherent Signals in the Presence of Correlated Noise

2012 ◽  
Vol 263-266 ◽  
pp. 157-161 ◽  
Author(s):  
Jin Zhang ◽  
Yun Xiang Mao ◽  
Jian Yun Zhang

With a uniform linear antenna array, a new direction-of-arrival (DOA) estimation method is proposed for wideband coherent signals in the presence of unknown correlated noise but with structured covariance matrix. Based on this proposed structure, i.e. Hermitian Toeplitz, a spatial differencing operation that exploits this symmetry is applied to remove the effect of the unknown noise and a new matrix is constructed accordingly at each frequency bin. Following this step, a focusing operation is performed to give the corresponding aligned covariance matrix. Finally, an eigenstructure-based DOA estimation method is applied. The validity of the method is supported by numerical simulation under various conditions.

Author(s):  
Hán Trọng Thanh ◽  
Nguyen Thanh Chuyen ◽  
Nguyen Xuan Quyen

CHAOS signal has been drawing a lot of research interest recently due to its performance in security systems. In this paper, an approach to estimate the direction of target for Distributed Chaos Radar System using Total Forward - Backward Matrix Pencil (TFBMP) algorithm. This algorithm works directly on signal samples of signals received by M – element Uniform Linear Antenna array. Therefore, the correlation between the received signals does not significantly impact on its performance and efficiency. This fact permits us to estimate not only wideband incoherent signals but also wideband coherent signals. Furthermore, this algorithm can also extract the Direction Of Arrival (DOA) with only one snapshot of signal, which means that the sampling frequency in real time receivers can be considerably reduced. The simulation results for DOA of incoming CHAOS signals using the proposed approach will be shown and analyzed to verify its performance.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4403
Author(s):  
Ji Woong Paik ◽  
Joon-Ho Lee ◽  
Wooyoung Hong

An enhanced smoothed l0-norm algorithm for the passive phased array system, which uses the covariance matrix of the received signal, is proposed in this paper. The SL0 (smoothed l0-norm) algorithm is a fast compressive-sensing-based DOA (direction-of-arrival) estimation algorithm that uses a single snapshot from the received signal. In the conventional SL0 algorithm, there are limitations in the resolution and the DOA estimation performance, since a single sample is used. If multiple snapshots are used, the conventional SL0 algorithm can improve performance in terms of the DOA estimation. In this paper, a covariance-fitting-based SL0 algorithm is proposed to further reduce the number of optimization variables when using multiple snapshots of the received signal. A cost function and a new null-space projection term of the sparse recovery for the proposed scheme are presented. In order to verify the performance of the proposed algorithm, we present the simulation results and the experimental results based on the measured data.


IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Batuhan Kaplan ◽  
Ibrahim Kahraman ◽  
Ali Riza Ekti ◽  
Serhan Yarkan ◽  
Ali Gorcin ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2964
Author(s):  
Alamgir Safi ◽  
Muhammad Asghar Khan ◽  
Muhammad Adnan Aziz ◽  
Mohammed H. Alsharif ◽  
Tanweer Ahmad Cheema ◽  
...  

This article deals with the application of differential geometry to the array manifolds of non-uniform linear antenna array (NULA) when estimating the direction of arrival (DOA) of multiple sources present in an environment using far field approximation. In order to resolve this issue, we utilized a doublet linear antenna array (DLA) comprising two individual NULAs, along with a proposed algorithm that chooses correct directions of the impinging sources with the help of the prior knowledge of the ambiguous directions calculated with the application of differential geometry to the manifold curves of each NULA. The algorithm checks the correlation of the estimated direction of arrival (DOAs) by both the individual NULA with its corresponding ambiguous set of directions and chooses the output of the NULA, which has a minimum correlation between their estimated DOAs and corresponding ambiguous DOAs. DLA is designed such that the intersection of all the ambiguous set of DOAs among the individual NULAs are null sets. DOA of sources, which imping signals from different directions on the DLA, are estimated using three direction finding (DF) techniques, such as, genetic algorithm (GA), pattern search (PS), and a hybrid technique that utilizes both GA and PS at the same time. As compared to the existing techniques of ambiguity resolution, the proposed algorithm improves the estimation accuracy. Simulation results for all the three DF techniques utilizing the DLA along with the proposed algorithm are presented using MATLAB. As compared to the genetic algorithm and pattern search, the intelligent hybrid technique, such that, GA–PS, had better estimation accuracy in choosing corrected DOAs, despite the fact that the impinging DOAs were from ambiguous directions.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Aihua Liu ◽  
Qiang Yang ◽  
Xin Zhang ◽  
Weibo Deng

A method of direction-of-arrival (DOA) estimation using array interpolation is proposed in this paper to increase the number of resolvable sources and improve the DOA estimation performance for coprime array configuration with holes in its virtual array. The virtual symmetric nonuniform linear array (VSNLA) of coprime array signal model is introduced, with the conventional MUSIC with spatial smoothing algorithm (SS-MUSIC) applied on the continuous lags in the VSNLA; the degrees of freedom (DoFs) for DOA estimation are obviously not fully exploited. To effectively utilize the extent of DoFs offered by the coarray configuration, a compressing sensing based array interpolation algorithm is proposed. The compressing sensing technique is used to obtain the coarse initial DOA estimation, and a modified iterative initial DOA estimation based interpolation algorithm (IMCA-AI) is then utilized to obtain the final DOA estimation, which maps the sample covariance matrix of the VSNLA to the covariance matrix of a filled virtual symmetric uniform linear array (VSULA) with the same aperture size. The proposed DOA estimation method can efficiently improve the DOA estimation performance. The numerical simulations are provided to demonstrate the effectiveness of the proposed method.


2012 ◽  
Vol 195-196 ◽  
pp. 109-114
Author(s):  
Yue Cui ◽  
Kai Hua Liu ◽  
Jun Feng Wang

A new direction of arrival (DOA) estimation method is proposed for coherent GPS signals, which applies to the GPS receiver with rich multipath, strong interference and low SNR. In this method, the interference is first suppressed by projecting the received signal onto the interference orthogonal subspace. Afterwards, the noise is eliminated by the spatial difference matrix. Then, the coherent GPS signals are decorrelated by the reconstructed Toeplitz matrix, and the DOA estimation is improved by a new constructed matrix. The proposed method can obtain more accurate DOA estimation for coherent GPS signals with strong interference and low SNR in the GPS receiver. Simulation results demonstrate the effectiveness and efficiency of the proposed method.


2014 ◽  
Vol 3 (2) ◽  
pp. 22-26
Author(s):  
V. S. Prabhu ◽  
◽  
V. P. Surya Surendran ◽  
V. G. Veena ◽  
◽  
...  

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