Principle Of Beamforming Research Articles

Development of an experimental technique for measuring polar diagrams of adaptive directivity implemented in hearing aids

Nowadays, hearing aids have efficient signal processing options to improve speech intelligibility in noise. This work concerns the characterization of the microphone systems directivity available in hearing aids. In recent decades, "adaptive" directivities have been implemented in hearing aids, thus making it possible to focus on useful sound sources in the hearing aid patient environment. These options use the principles of sound environments detection, acoustic beamforming and noise reduction. Performances of these options can be estimated with subjective methods (as speech audiometry in noise), and objective methods (listening effort, intelligibility indicators as HASPI, SII, STI, etc.). But these methods provide an overall assessment of all the processing involved in speech enhancement and are not designed to characterize the effects of adaptive directivity. We developed an experimental technique based on sound sources separation with phase opposition diffusion (known as "Hagerman" method) to draw polar diagrams of adaptive directivity, for realistic sound environments. We used a sound multi-diffusion system to generate various sound environments with noise and speech sources around an artificial head equipped with hearing aids. The first results show the adaptive directivity effects associated with noise reduction provided by the latest hearing aids generation on everyday hearing scenes.

On Beamforming with the Single-Sideband Transform

In this paper, we examine the use of the Single-Sideband Transform (SSBT) for convolutive beamformers. We explore its unique properties and implications for beamformer design. Our study sheds light on the tradeoffs involved in using the SSBT in beamforming applications, offering insights into both its strengths and limitations. Despite the advantage of having real-valued coefficients, we show that the convolution handling of the transform presents challenges that impact fundamental beamforming principles. When compared to the Short-Time Fourier Transform (STFT), the SSBT displays lower robustness, especially in scenarios involving mismatch and modeling noise. Notably, we establish a direct equivalence between the SSBT and STFT when using identical transform parameters, enabling their seamless interchangeability and joint use in time–frequency signal enhancements. We validate our theoretical findings through realistic simulations using the Minimum-Power Distortionless Response beamformer. These simulations illustrate that although the STFT performs marginally better than the SSBT under optimal conditions, it outperforms significantly in non-ideal scenarios.

A review of beamforming microstrip patch antenna array for future 5G/6G networks

With the increase in demand for high data rates and high bandwidth because of multiple users all over the globe, the technology has moved toward the next-generation of wireless communication. This rapid advancement of wireless communication technologies has led to the emergence of 5G networks, which promise significantly higher data rates, lower latency, and enhanced connectivity. Researchers believe that five essential techniques can enable 5G. Beamforming is one of those essentials, as it plays a vital role in achieving reliable and high-capacity communication. This review article portrays a comprehensive analysis of the 5G beamformer Microstrip Patch Antenna array techniques for communication systems. The paper comprises of a deep overview of the fundamental concepts and principles of beamforming, including analog, hybrid, and digital beamforming techniques. It explores the advantages and disadvantages of each approach and discusses their suitability for 5G applications. An in-depth examination of various beamforming techniques employed in 5G, encompassing traditional beamforming, massive Multiple-Input-Multiple-Output beamforming, hybrid beamforming, and adaptive beamforming. The discussion encompasses the strengths, weaknesses, and performance trade-offs of each technique, along with their applicability in diverse deployment scenarios and applications. The review of multiple couplers that are used for the feeding of the antenna is discussed with included hybrid coupler, Wilkinson power divider, branch line coupler, and butler matrix in beamformer smart antenna for 5G/6G communications. Numerous beamforming techniques are compared based on their merits, demerits, and applications. Moreover, the dielectric substrate utilized to design the beamformer was also reviewed. The findings presented in this paper serve as a valuable resource for the researcher, scholars, and engineers working in the field of 5G wireless communications and antenna designing, facilitating the development and deployment of efficient and robust beamforming solutions for future 5G networks.

A GPU‐based real‐time processing system for frequency division multiple‐input‐multiple‐output radar

AbstractMultiple‐Input‐Multiple‐Output (MIMO) radar has the characteristic of multiple antenna channels, bringing on a big data volume for signal processing. Therefore, the trade‐off between detection ability and computational efficiency is always considered. In this article, an optimisation system is proposed to enhance the real‐time performance of frequency division MIMO radar without compromising accuracy. For the scenario of low‐altitude small target detection, a signal processing acceleration method is proposed and a MIMO radar optimisation system based on graphics processing unit (GPU) architecture is built. The signal model of frequency division MIMO radar is first established, improving the classical signal processing flow efficiency from the perspective of reducing fast Fourier transform (FFT) times and windowing operation times. To achieve an advanced acceleration, the parallel architecture of ArrayFire‐library in GPU is then employed. Distinct minimum parallel units are extracted by analysing the principle of digital beamforming (DBF), pulse compression, moving target detection (MTD), and constant false‐alarm rate (CFAR) algorithms. And the corresponding parallel algorithms are designed to constitute a parallel acceleration system of frequency division MIMO. Simulation results indicate that the proposed method significantly improves the efficiency of MIMO system with a maximum acceleration ratio of 65 times, meeting the real‐time processing requirements.

IRS-Aided Uplink Transmission Scheme in Integrated Satellite-Terrestrial Networks

This paper proposes an intelligent reflecting surface (IRS)-aided uplink transmission scheme to expand the wireless coverage and improve spectral efficiency for an integrated satellite-terrestrial network (ISTN). Here, multiple earth stations communicate with the satellite via non-orthogonal multiple access (NOMA) technology, while multiple direct users and blockage users access the cellular network through space division multiple access and IRS-aided NOMA technology, respectively. In particular, we first aim at maximizing the ergodic sum rate of the ISTN subject to the quality-of-service requirements and transmit power budgets of all users, yielding a constrained optimization problem. Then, based on the assumption that only the statistical channel state information (CSI) is available, we propose a two-layer alternating algorithm to solve the non-convex original problem. The algorithm combines successive convex approximation with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$S$</tex-math></inline-formula> -procedure approach to calculate the phase shifts of IRS and transmit powers of all users in the first layer, and uses Charnes-Cooper method with semi-definite programming to calculate beamforming vectors at the BS in the second layer. Furthermore, with the help of the zero-forcing beamforming principle, we propose a low-complexity algorithm to solve the problem that can reduce the computational load effectively. Finally, simulation results demonstrate that our proposed algorithms can obtain a higher ergodic sum rate than the benchmarks.

Measurement resolution of acoustic reflection imaging logging with a cylindrical phased array acoustic receiver station

Azimuthal acoustic reflection imaging logging plays an important role in the exploration and development of fracture-cavity reservoirs, because it can image geological structures within tens of meters around the borehole. However, minimal evaluations have been conducted for the detection of small-scale geological anomalies, particularly the simultaneous measurement of multiple small-scale scatterers. In this study, the scanning-reception implementations of phased array acoustic receiver stations in the Borehole Azimuthal Acoustic Reflection Imaging Tool (BAR) were developed based on the beamforming principle. The measurement responses of BAR were simulated and the scanning-reception performances of arcuate phased array (APA) and cylindrical phased array (CPA) acoustic receiver stations were compared using a three-dimensional (3D) finite difference algorithm for one or two small-scale caves in a formation away from a fluid-filled borehole. The azimuth and elevation measurement resolutions of CPA acoustic receiver stations were determined by analyzing the scattered wavefields under the circumstances of two caves on the same horizontal or vertical plane. Numerical simulation results showed that the echo waves scattered from small-scale caves were similar to those reflected by large-scale formation interfaces outside the borehole. The azimuth angle of a single cave could be obtained by calculating the amplitudes of P–P echoes at different azimuths received by the APA acoustic receiver station. Compared with the APA scanning-reception mode, the 3D scanning-reception mode based on the CPA acoustic receiver station was more applicable when two caves were simultaneously located outside the borehole. Under the calculation conditions of this study, the CPA acoustic receiver station had a limit azimuth resolution of ∼60°–90° and a limit elevation resolution of ∼8.8°–17.4° when two scatterers were located on the same horizontal or vertical plane. This work verified the superiority of the CPA scanning-reception mode for the detection of small-scale geological anomalies and provided a theoretical basis for the wider application of BAR.

Music Genre Classification Algorithm Based on Multihead Attention Mechanism

Retrieving music information is indispensable and divided into multiple genres. Music genres can be attributed to set categories, which are the indispensable functions of intelligent music recommendation systems. To improve the effect of music genre classification and model construction, combined with the music genre classification algorithm, this paper combines the multihead attention mechanism to study the music genre classification algorithm model, and it analyzes the key technology of music beamforming. Moreover, this paper has made a detailed description and derivation of the array antenna model, the principle of music beamforming, and the performance evaluation criteria of music adaptive beamforming. In the second half, the nonblind classical LMS algorithm, RLS algorithm, and variable step size LMS algorithm of adaptive beamforming are studied in detail. A music genre classification algorithm model based on the multihead attention mechanism is constructed. It can be seen from the experimental research that the music genre classification algorithm based on the multihead attention mechanism proposed in this paper has obvious advantages compared with the traditional algorithm, and it has a certain role in music genre classification.

Research on 5G Video Security Communication Technology Based on Massive MIMO

Background: The paper aimed at studying a large number of classified and sensitive information transmission security issues brought by 5G mobile communication system. Methods: In this paper, the principle of beamforming and its shortcomings are introduced by combining the large-scale MIMO technology and directional modulation technology, and the directional modulation technology based on antenna subset selection and the hybrid array is introduced to realize the safe transmission target. The results show that large-scale MIMO technology has become a key technology of 5G mobile communication, but the factors such as multipath fading in the actual wireless channel have not been fully considered, and the accurate estimation error of channel state information (CSI) will affect the ideal security level it can achieve. Results: The combined application of massive MIMO technology and directional modulation technology in the 5G system brings security to its communication. Conclusion : Directional modulation technology based on signal modulation has become an important research point of the 5G system because it does not need to consider the eavesdropper's computing power and can achieve the purpose of safe transmission by disturbing the signal constellation in the unexpected direction.

Improving Deep Coverage of 4G Network Based on Massive MIMO Beamforming Used in 5G

Although 5G era has come, the comprehensive coverage of 5G will take a long time for the vast number of underdeveloped countries and regions. Therefore, it is still significant to improve the depth coverage of 4G network. Massive Multi‐in Multi‐out (MIMO) is an application of 5G key technology in 4G network. In this study, based on the theoretical principle of beamforming, a special beamforming was realized by combining precoding and direction‐of‐arrival (DOA) estimation of sounding reference signal (SRS) in Massive MIMO antenna. Moreover, this beamforming antenna was applied to the existing 4G network. The building of deep coverage between indoor distribution and beamforming antenna was compared. It found that beamforming antenna can gain 6–8 dB beamforming gains and the overage coverage effect is better than indoor distribution. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Three-dimensional localization of point acoustic sources using a planar microphone array combined with beamforming.

This paper presents a beamforming-based acoustic imaging (BBAI) method employing a two-dimensional (2D) microphone array that not only can locate an acoustic source in the XY plane parallel to the array, but can also identify the distance between the source and array in the Z direction, denoted as the source depth, and thus provides three-dimensional (3D) localization ability. In this method, the acoustic field is reconstructed on virtual XY planes at different distances along the Z direction. The source depth is then determined according to the virtual plane providing the maximum response of the acoustic field. The location of the source in the X and Y directions of the identified virtual plane can then be easily determined based on the standard beamforming principles of a planar array. The proposed BBAI method is evaluated based on simulations involving single- and multiple-point sources, and corresponding experimental evaluations are similarly conducted in an anechoic chamber. Both simulation and experimental results demonstrate that the proposed method is capable of locating acoustic sources in 3D space.

Covariance Matrix Reconstruction With Interference Steering Vector and Power Estimation for Robust Adaptive Beamforming

To ensure link reliability and signal receiving quality, robust adaptive beamforming (RAB) is vital important in mobile communications. In this paper, we propose a new RAB algorithm based on interference-plus-noise covariance (INC) matrix reconstruction and steering vector (SV) estimation. In this method, the INC matrix is reconstructed by estimating all interferences SVs and powers, as well as the noise power. The interference SVs are estimated by using the Capon spatial spectrum together with robust Capon beamforming principle, subsequently the interference powers are estimated based on the orthogonality between different signal SVs. On the other hand, the desired signal SV is estimated via maximizing the beamformer output power by solving a quadratic convex optimization problem. The proposed algorithm only needs to know in advance the array geometry and angular sector, in which the desired signal lies. Simulation results indicate that the proposed algorithm outperforms the existing RAB techniques in terms of the overall performance in cases of various mismatches.

Spatial Coherence of Backscattered Signals in Multi-Line Transmit Ultrasound Imaging and Its Effect on Short-Lag Filtered-Delay Multiply and Sum Beamforming

In Multi-Line Transmission (MLT), high frame-rate ultrasound imaging is achieved by the simultaneous transmission of multiple focused beams along different directions, which unfortunately generates unwanted artifacts in the image due to inter-beam crosstalk. The Filtered-Delay Multiply and Sum (F-DMAS) beamformer, a non-linear spatial-coherence (SC)-based algorithm, was demonstrated to successfully reduce such artifacts, improving the spatial resolution at the same time. In this paper, we aim to provide further insights on the working principle and performance of F-DMAS beamforming in MLT imaging. First, we carry out an analytical study to analyze the behavior and trend of backscattered signals SC in MLT images, when the number of simultaneously transmitted beams and/or their angular spacing change. We then reconsider the F-DMAS algorithm proposing the “short-lag F-DMAS” formulation, in order to limit the maximum lag of signals used for the SC computation on which the beamformer is based. Therefore, we investigate in simulations how the performance of short-lag F-DMAS varies along with the maximum lag in the different MLT configurations considered. Finally, we establish a relation between the obtained results and the signals SC trend.

基于均匀圆阵的简正波模态分解

浅海波导海洋环境复杂，声波往往以简正波的形式进行传播。简正波的模态分离对于浅海波导中的目标探测与定位有着重要的意义。由于线阵在做模态分离时有着很大的局限性，本文结合简正波的传播特性基于均匀圆阵提出了一种简正波模态分离方法。首先应用圆阵对目标方位进行估计，结合方位信息利用模态域波束形成原理，做波数域上的波束形成，得到各阶简正波的模态强度并实现波数域上的模态分离。本文从理论上推导了圆阵上的模态域波束形成以及模态分离的过程，并用仿真对圆阵的模态分离方法进行了验证。仿真结果表明：该算法无需海洋环境条件作为先验知识，即可在波数域对模态进行分离，并能对水平波数做出较为准确的估计。 Shallow sea waveguide has complicated marine environment. Sound waves often propagate in a simple form. Modal separation of Normal mode is very important for target detection and location in shallow sea waveguides. The linear array in the modal separation has great limitation. Combined with the propagation characteristics of normalmodes, the separation method which is based on uniform circular array of a normal mode is proposed. Firstly, the target position is estimated by using circular array, and the modal intensity of each order Normal mode is obtained by combining the azimuth information and the beamforming principle of mode domain, do the beam forming on the beam domain and the modal separation is achieved. In this paper, we use the beamforming theory of modal domain on a circular array, and the results are verified by simulation. Simulation results show that the algorithm, without marine environment conditions as a priori knowledge, can separate the modal and estimate the horizontal wavenumber.

Experimental Research of Vector Hydrophone MVDR Algorithm

The estimation of Direction of Arrival (DOA) is an important issue of underwater acoustic signal processing. The purpose of beamforming is to form the directivity of the target direction and to catch the target efiectively. So, the beamforming technology is widely used in this fleld. Vector Hydrophone simultaneously extract sound pressure and velocity information of sound sources. After that, the phase shift information between the amount of the hydrophone array increases. Beamforming technology based on vector hydrophone performance was signiflcantly better than the sound pressure hydrophone. During this research, flrstly, do conventional beamforming theoretical description and simulation analysis, based on the conventional beamforming where MVDR (Minimum Variance Distortionless Response) beamforming principles were introduced, and then based on vector hydrophone do comparison simulation by various ways. Simulation results show that, MVDR beamforming has a higher resolution and antijamming capability related to conventional beamforming which is suitable for low SNR environment underwater acoustic signal processing. Finally, process the experimental data by the above two methods, the results show MVDR beamforming can be efiectively detected, and has a higher resolution.

3D beamforming: Performance improvement for cellular networks

The beam pattern of a mobile communication base station has significant impact on the performance of a cellular network. Three-dimensional (3D) beamforming combines the horizontal beam pattern adaptation, as applied for beamforming and multiple input multiple output (MIMO) schemes, with a vertical antenna pattern adaptation. The recent availability of new flexible antenna techniques enables a fully dynamic antenna pattern adaptation which can be specified per resource block and user equipment (UE), and makes 3D beamforming practically feasible. This paper describes the basic principles of 3D beamforming, including the impact of downtilt adaptation on the physical layer as well as the potential of its combination with beam coordination involving the media access control (MAC) layer. Our investigations assumed the vertical main lobe of the beam pattern was geometrically pointed towards the UE. We discuss a number of different realization options and simulation results including a Bell Labs field trial with vertical beam steering. Using wireless systems with state of the art Long Term Evolution (LTE) signal format and including the lightRadio™ antenna array, our trials in the Stuttgart testbed verified the basic predicted properties and potential advantages of 3D beamforming.

Wideband Beamforming Based on Farrow Structure

In this paper, the principles of digital beamforming (DBF) and farrow structure are presented. Sum-of-powers-of-two (SOPOT) and cut-set retiming are used for saving the FPGA multiplier consumption and improving the running speed of farrow structure. A design example is given and the FPGA resource consumption saving is discussed also. The corresponding test results demonstrate the effectiveness of the fractional delay. With the fractional delay, it’s easy to realize wideband beam steering and digital beam forming.

Localization and identification of three-dimensional sound source with beamforming based acoustic tomography

Beamforming based commercial planar microphone array could only localize and identify the sound source when the distance between source and array is known. This paper presents a beamforming based acoustic tomography (BBAT) method to locate and identify the source in 3D space, say, the BBAT method can not only locate the source in X-Y plane that is parallel to the array, but also the depth Z of the source. In this method, the sound field is reconstructed on the virtual planes at different distances along depth direction (Z direction). The maximum response of sound field on every virtual reconstruction plane is tracked, where the largest value among those maximum responses appears at Z direction is the depth of the source. The location of source at X and Y directions can then be easily identified based on beamforming principle, which is utilized by commercial planar array. The BBAT method is evaluated theoretically by simulation of monopole source, the experimental evaluation is done as well in anechoic chamber. The results from both simulation and experiment indicate that this method is capable to locate and identify sound source in 3D space. However, it cannot recognize the sound source located in front of the planar array or behind because of the genetic limitation of 2D planar array in identification of source depth.

초음파진단기의 빔포밍 기술

초음파진단기는 1950년대부터 사용되기 시작했고 그 동안 꾸준한 기술 발전을 통해 현재 대부분의 병원에서 필수불가결한 영상진단장비로 널리 활용되고 있다. 1970년대 초음파진단기에 어레이 프로브가 사용되기 시작한 이래로 전자적 신호처리를 통한 빔포밍 기술이 초음파진단기에 적용되었고, 꾸준히 개선되어 왔다. 빔포밍 기술은 초음파진단기의 해상도를 결정짓는 중요한 신호처리 기술이다. 이 논문에서는 이 빔포밍 기술의 원리부터 최근 동향까지 간략히 소개하고자 한다. 여기에는 어레이 프로브(array probe)를 사용하는 빔포밍의 원리, 기본적 이론, 실제 구현 등이 포함되고, 또 최근 기술 중 합성구경영상(synthetic aperture imaging: SAI), 적응형 빔포밍(adaptive beamforming), 2차원 어레이 프로브를 사용하는 2차원 빔포밍 기술 등의 주제도 소개한다. 이런 다양한 빔포밍 기술들은 다양한 다른 분야의 기술들과 여러 가지 형태로 발전적으로 융합하면서 시스템의 성능을 지속적으로 향상시켜 갈 것이다. Medical ultrasound systems have been used since 1950s, and are now widely used in most hospitals as indispensable diagnostic imaging systems. Since array probe was introduced in 1970s, beamforming technology using electronic signal processing has been adopted to the medical ultrasound system, and has been improved. Beamforming is a important technology which defines the resolution of the ultrasound system. In this paper, the technologies are introduced from basic beamforming principles to current trend. They include principles of beamforming using array probe, basic theory, and practical implementation, and recent topics of synthetic aperture imaging, adaptive beamforming, 2-dimensional beamforming using 2-dimensional array are also introduced. These various technologies will improve system performances continuously by merging innovatively with various technologies in other fields.

Ultrasound beamformer using pipeline-operated S/H delay stages and charge-mode summation

The proposed ultrasound beamformer is based on the delay-and-sum beamforming principle. The circuit consists of several programmable delay lines. Each delay line is constructed by pipeline-operated sample-and-hold (S/H) stages with digitally-assisted delay control, which ensure delay-independent gain and good timing accuracy. The summation is realised in the charge domain using the charge-averaging method, which consumes virtually no extra die area or power. A prototype beamformer has been fabricated in a 0.35 µm CMOS process to interface nine transducer elements. Measurement results show that this circuit consumes much less power and chip area than the prior art, while maintaining good accuracy and flexibility.

Frequency-swept directivity lobes—An emerging functional principle of biosonar beamforming

In all bat species, the spatial sensitivity of the biosonar system is mainly determined by the shape of the outer ears. In addition, a noseleaf surrounds the nostrils in many species and shapes the spatial distribution of the emitted sound energy. Predicting the beam-forming effects of these structures numerically from their surface geometry has enabled comparative studies of high-resolution beam pattern estimates across a large set of different bat species. The beam patterns obtained so far differ from common manmade transducers, such as loudspeakers and microphones. Strong asymmetric side lobes, which change direction as a function of frequency, are a distinguishing feature consistently seen in emission and reception beam patterns of the bats. Where investigated, the occurrence of these side lobes appears to be tied to the presence of flap-like structures (including the tragus of the pinna), which may be hypothesized to have evolved for this purpose. The presence of these side lobes suggests that bat biosonar has not been evolved to maximize the ensonification energy and sensitivity for a single small target unconditionally. Instead, the function of these strong side lobes could be explained as maximizing the information obtained in analogy to squinted beams used in manmade systems.