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 contribution, a new room-temperature terahertz source is proposed for overcoming the power limitations inherent to photomixer-based generators. Specifically, a manufactured vertical “large area emitters” is described and analyzed by proposing a Hertzian dipole array model. An estimation of its radiation pattern is included and will be compared with experimental measurements.
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 paper, two compressive DoA estimation algorithms are investigated, namely the sparse ruler, and the coprime sampling array. These algorithms explore the eigen matrix structure of a non uniform linear array in order to artificially synthesize a larger uniform linear array, in this way boosting the capability of a DoA tracking system beyond the theoretical limit of the number of sources that...
The accuracy of direction of arrival estimation tends to degrade under reverberant conditions due to the presence of reflected signal components which are correlated with the direct path. The recently proposed direct-path dominance test provides a means of identifying time-frequency regions in which a single signal path is dominant. By analysing only these regions it was shown that the accuracy of...
We consider frequency selective channel estimation in the uplink of massive MIMO-OFDM systems, where our major concern is complexity. A low complexity distributed LMMSE algorithm is proposed that attains near optimal channel impulse response (CIR) estimates from noisy observations at receive antenna array. In proposed method, every antenna estimates the CIRs of its neighborhood followed by recursive...
Direction Of Arrival (DOA) estimation is a well known problem that has been studied through a wide range of different approaches and methods. Most of these methods make use of several snapshots in the array to provide an accurate result but their performance is commonly degraded when only a single snapshot is available. An improved ESPRIT algorithm to the problem of direction of arrival (DOA) estimation...
Sound source localization, tracking and homing in play an important role in human-robot interaction. The frequent tracking of a moving acoustic source is computationally expensive for any real time application. In this paper, we propose a simple algorithm based on the sign of time delay of arrival estimation (STDE). Also a special Y-array microphone is designed which is well suited for real time tracking...
This contribution presents a Direction of Arrival (DoA) estimation algorithm based on the complex Watson distribution to incorporate both phase and level differences of captured microphone array signals. The derived algorithm is reviewed in the context of the Generalized State Coherence Transform (GSCT) on the one hand and a kernel density estimation method on the other hand. A thorough simulative...
Carrier frequency and its corresponding direction of arrival (DOA) estimation, at sub-Nyquist sampling rates of narrowband (bandwidth not exceeding B Hz) sources is considered in this paper. We assume M physical sensors arranged in a two dimensional nested sensor array configuration and propose to modify the receiver architecture by inserting an additional delay channel to only the dense sensor array...
This work proposes a novel method for 3D direction of arrival (DOA) estimation based on the sound intensity vector estimation, via the encoding of the signals of a spherical microphone array from the space domain to the spherical harmonic domain. The sound intensity vector is estimated on detected single source zones (SSZs), where one source is dominant. A smoothed 2D histogram of these estimates...
Multipath signals are main source of error for parameter estimation in direction finding applications. In this paper, a new method is proposed for the estimation of direction-of-arrivals (DOA) of a far-field source and localization of its near-field multipath reflections in two steps. Firstly, far-field source DOA is estimated using a calibration technique. In the second step, a near-to-far field...
Array radio telescopes are suitable for the implementation of spatial filters. These filters present the advantage of canceling potential radio frequency interference (RFI) while recovering uncorrupted Time-Frequency data, of interest to astronomers. Although information regarding the sources of RFI can be a priori known or reliably inferred, the complexity of radio telescope systems randomizes the...
We propose a novel wideband acoustic direction finding method for highly reverberant environments using measurements from a single Acoustic Vector Sensor (AVS). Since an AVS is small in size and can be effectively used within the full acoustic frequency bands, the proposed solution is suitable for wideband acoustic source localization. In particular, we introduce a novel approach to extract the signal...
This paper considers the scenario when a mix of signals from multiple acoustic sources is received by a microphone array. The problem is to estimate the waveform of the source of interest located in the near field of the array. The considered problem can arise in many applications such as video conferencing, acoustic room surveillance and others, when it is necessary to capture human speech against...
In this paper, a partially adaptive two dimensional (2D) trans mit beamforming approach is proposed to enable search-free azimuth and elevation direction of arrival (DOA) estimation in MIMO radar. Specifically, the 2D transmit array is non-adaptively partitioned into a number of subarrays. Then, a beamspace matrix is adaptively designed for each subarray, such that the beampatterns corresponding to...
In this paper, a novel array-based method to estimate the path loss exponent (PLE) is developed. The method is designed as a part of an automatic calibration step, prior to localization of a source transmitting in the near-far field of the array. The method only requires the knowledge of the ranges between the array elements. By making the antenna elements transmit in turn, the array response model...
In wireless acoustic sensor networks (WASNs), sampling rate offsets (SROs) between nodes are inevitable, and recognized as one of the challenges that have to be resolved for a coherent array processing. A simplified free-space propagation is considered with a single desired source impinging a WASNs from the far-field and contaminated by a diffuse noise. In this paper, we analyze the theoretical performance...
In this paper we describe an estimator for the canonical polyadic (CP) tensor model using order statistics of the residuals. The estimator minimizes in an iterative and alternating fashion a dispersion function given by the weighted ranked absolute residuals. Specific choices of the weights lead to either equivalent or approximate versions of the least squares estimator, least absolute deviation estimator...
Radio frequency identification (RFID) technology is one of the key technologies to make possible the Internet of Things (IoT). There are increasing needs to localize multiple RFID-tagged items which are closely spaced. As a result, localization techniques with higher accuracy yet low implementation complexity are required. This paper examines the applicability of the direction-of-arrival (DOA) estimation...
A single piece horizontally polarized cylindrical antenna array is designed and prototyped. It provides accurate alignment of the antenna elements and easy assembling of the antenna as all the antenna elements and the feeding network are printed on a single piece of circuit board. The cylindrical arrangement of the radiation elements provides a full coverage of the entire azimuth plane for radar applications...
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.