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In this paper, a beamforming system for LTE- Advanced based on Array sampling technology is proposed. Antenna Array that has been designed covers LTE mid and high bands. RF multiplexer 8x1 switch has been designed and simulated. The system is composed of agile RF frontend and FPGA digital signal processing unit.
We present an iterative method for joint antenna-array calibration and direction of arrival estimation using millimeter-wave (mm-Wave) radar operating at 77 GHz. The calibration compensates for antennaarray coupling, and phase and gain errors, and does not require any training data. This method is well suited for applications, such as automotive radars, where multiple antenna elements are packaged...
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...
Collision avoidance systems for Unmanned Aerial Vehicle (UAV) use ultrasonic or radiowave radar equipment for target detection. In direction-of-arrival (DOA) antenna array estimation, the direction of a signal is usually assumed to be a point. The article analyze the Uniform Linear Array(ULA) and Minimum Redundance Array (MRA) beamforming arrays taken into account the mutual coupling between the antenna...
In this contribution a broadband biquad antenna array for DOA applications is investigated. Simulation and measurement results of the single broadband biquad antenna element and results of antenna array configurations for vertical polarisation, horizontal polarisation or polarisation independant direction of arrival estimation using different algorithms are shown.
Due to its low received power, a GPS signal is vulnerable to both intentional and unintentional interferences. In this paper, the problem of estimating the direction of arrival of a weak GPS interference, which has the same power level as the GPS signals or is even weaker than them, using a GPS antenna array is considered. To achieve this, a multiple subspace projection algorithm is proposed to cancel...
In this paper, we propose a novel distortion calibration algorithm for uniform circular array (UCA) based on its special structure. A near-field calibration antenna, located in the center of circular array, is used to estimate the gain and phase uncertainties of elements. Besides, a single far-field source is used to estimate the direction-of-arrival (DoA) and mutual coupling matrix (MCM). Finally,...
In this paper we propose an approach to 3-D ambiguity (type I ambiguity [l]) analysis of arbitrary antenna arrays. Ambiguity characterization is very important in designing antenna array for direction finding in mobile communications/indoor positioning/radar, which greatly influences practical capability of Direction of Arrival (DOA) estimation. Conventional 2-D ambiguity analysis loses most of ambiguity...
Many classical direction of arrival (DOA) estimation algorithms suffer from sensitivity to mutual coupling of antenna array. In this paper, a stable estimation method of DOA estimation is introduced. This method is applying a group of auxiliary arrays, exploiting the banded symmetric and Toeplitz matrix model for the mutual coupling in a uniform linear array (ULA), based on the estimation of signal...
In this paper, we propose a Minimum Bit Error Rate (MBER) beamforming combined with Space-Time Block Coding (STBC) according to the number of antenna array. A class of adaptive beamforming algorithm has been proposed based on minimizing the BER cost function directly. Consequently, MBER beamforming is capable of providing significant performance gains in terms of a reduced BER. The beamforming weights...
Current automotive radar systems measure the distance, the relative velocity and the direction of objects in their environment. This information enables the car to support the driver. When objects cannot be completely separated by their distance or relative velocity, a two object direction of arrival estimator must normally be used to separate the objects. In this paper we take a close look at the...
This paper treats the problem of joint estimation of time-delay, Doppler frequency, and spatial (direction-of-arrival or DOA) parameters of several replicas of a known signal in an unknown spatially correlated noise field. Both spatially unstructured and structured data models have been proposed for this problem and corresponding maximum likelihood (ML) estimators have been derived. However, structured...
Since wireless communications began to take an abrupt rise, with the development of techniques which were introduced for the growth of data transfer, antenna systems were considered to be the ideal choice to obtain the wanted results. Nevertheless these techniques required the development of certain algorithms also, to facilitate the recognition of the signals at the reception side (direction of arrival...
Estimation of Direction of Arrival (DOA) signal is one important function of adoptive antenna. The fuzzy angle in correlative signal environment of DOA estimation could seriously affect the estimation precision. Based on 1-D spatial smoothing theory the paper analyzes the algorithm for 2-D angle estimation in correlative source environment of hexagonal array and simulations were carried out. A method...
Most of the array signal processing methods for the estimation of the direction of arrival angle estimation (DOA) for multiple incident sources are based on the far-field assumption. When the sources are located close to the antenna array, these methods are no longer valid. In this paper, a new method is presented for the joint range and DOA estimation for multiple near-field sources. The proposed...
The estimation of the position of an emitting source is an important aspect of emerging cognitive radio systems. We readdress the known problem of estimating the Direction-of-Arrival (DOA) of an emitting source via passive radio means, namely an antenna array. The challenges in the considered scenarios are (a) time-varying, terrestrial multipath propagation with medium-to-low SNR and (b) very short...
This paper analyzes a method for the DOA estimation of correlated signals based on the integration of a SVM classifier and an iterative multi-scaling approach (IMSA). The aim of the SVM classifier is the definition of a probability map of the angular directions of incidence of the incoming signals starting from the knowledge of the correlation matrix of the antenna array, while the IMSA procedure...
The Multiple Signal Classification (MUSIC) algorithm is a powerful technique for determining the Direction of Arrival (DOA) of signals impinging on an antenna array. The algorithm is serial based, mathematically intensive, and requires substantial computing power to realize in real-time. Recently, multi-core processors are becoming more prevalent and affordable. The challenge of adapting existing...
An efficient nonlinear direction of arrival estimation method based on robust statistics is developed for a CDMA receiver to mitigate impulsive noise effects in multipath environments. The proposed scheme is derived from the sample myriad-based covariation matrix. Simulation results demonstrate that the proposed scheme significantly outperforms other linear and non-linear schemes.
An experimental study of direction-of-arrival (DOA) estimation using a compact antenna array is presented. Compared to standard antenna array with a half wavelength element separation, the element separation of the compact array used in this experiment is only a quarter wavelength. As will be demonstrated, the strong mutual coupling effect of this compact array can be almost totally removed by using...
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