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Beamspace adaptive array antenna for broadband signals

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 1997年第10期80卷 38-48页

作者： Sekiguchi, T Miura, R Karasawa, Y ATR OPT & RADIO COMMUN RES LABSKYOTO 61902JAPAN

In this paper, we propose a beamspace adaptive array antenna for broadband signals with a wide fractional bandwidth. The proposed beamspace adaptive array antenna has a multiple digital beamforming network that preserves spectral components of input broadband signals by using tapped-delay-line circuits. Coefficients of the tapped-delay-line circuits are determined such that each broadband digital beamforming network has the same phase characteristics, and the beam pattern including sidelobe and null characteristics is virtually frequency independent. A few adaptive weights, which are linear combination coefficients of the selected broadband beams, follow a beam selector. The number of adaptive weights for the proposed adaptive array is considerably less than that of an element space structure with tapped-delay-line circuits. We demonstrate by computer simulation that interference suppression by the proposed beamspace adaptive array is as good as that of an element space adaptive array and that it has much faster convergence. (C) 1997 Scripta Technica, Inc.

关键词： adaptive array digital beamforming antenna adaptive signal processing

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Automatic calibration method of adaptive array with linear array utilizing signal circulation among antennas (ACT-FL)

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS 2004年第8期87卷 20-31页

作者： Nishimori, K Cho, K Hori, T NTT Corp Network Innovat Labs Yokosuka Kanagawa 2390847 Japan Univ Fukui Fukui 9108507 Japan

An adaptive array for a frequency division duplex (FDD) system requires calibration among the antennas, the cables, and the transmitters and receivers to form the desired transmission directivity. In this paper, we propose the Automatic Calibration method of adaptive array using Transmitting signals for FDD systems with Linear array (ACT-FL) by using the signal circulation among the antennas and not using any additional elements or external information for calibrating the antennas and cables. By studying the calibration accuracy of the ACT-FL through analysis and tests including the mutual coupling of the antennas, we explain the applicable element spacing and the beam width in ACT-FL. We also evaluate the signal-to-interference power ratio (SIR) at the interference arrival time from radiation pattern measurements by using a testbed implementing ACT-FL and demonstrate the effectiveness of ACT-FL. (C) 2004 Wiley Periodicals, Inc.

关键词： adaptive array automatic calibration FDD system element spacing beam width

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BEAM-SPACE CMA adaptive array ANTENNAS

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 1995年第2期78卷 85-95页

作者： CHIBA, I CHUJO, W FUJISE, M Member ATR Optical and Radio Communications Research Laboratories Kyoto Japan 619-02

In the communication system using a constant modulus signal, a constant modulus algorithm (CMA) adaptive array antenna is effective for elimination of the frequency-selective fading generated in multiple propagation paths. On the other hand, in the system in which CMA adaptive loops are installed for each antenna element in an array with more than 10 elements used for mobile satellite communication, the computing time and the amount of hardware become excessive. In this paper, a beam-space CMA adaptive array antenna (BSCMA) is proposed in which a portion of the multibeam output is selected to form a CMA adaptive array. In the BSCMA, first, a multibeam is formed by means of a fast Fourier transform (FFT) and only the beams whose output power exceeds a threshold level are selected. An adaptive process is carried out with the CMA as a guiding principle only for the selected beam outputs. The BSCMA has an advantage of carrying out the capture of the desired wave and the elimination of the interference wave effectively with degrees of freedom corresponding to the number of arriving waves. The method is effective for an adaptive antenna system applied to an array antenna constructed with many antenna elements. In this paper, the configuration of the BSCMA is shown and its characteristics are investigated by the numerical simulation.

关键词： INTERFERENCE array ANTENNA adaptive array MULTIBEAM MOBILE SATELLITE COMMUNICATION

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Cochannel interference cancellation by base station adaptive array in uncorrelated Rayleigh fading channel

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 2000年第5期83卷 97-106页

作者： Katoh, Y Ohgane, T Ogawa, Y Itoh, K Hokkaido Univ Grad Sch Engn Sapporo Hokkaido 060 Japan

The interference cancellation characteristics of an adaptive array are discussed when the fading at each element is uncorrelated assuming low height base station. In this paper, we focus on the case that the number of antennas and interference waves is large. From the investigation of SINR characteristics we have found that when the average SNR is large, no diversity gain is obtained, but when the average SNR is small, the diversity gain is increased. In the BER characteristics when the number of antennas is less than 7, an increase in the number of antennas increases the gain. However, when the number is greater than 10, diversity gain is obtained due to extra degrees of freedom. While studying the influence of fading variation (uplink, downlink), we have found that deterioration is small in the uplink when the normalized Doppler frequency is less than 1 x 10(-4) in the RLS and SMI interpolation method, and nearly complete tracking is possible. In case of the downlink, the floor error is less than 1 x 10(-2) when the normalized Doppler frequency is less than 1 x 10(-4) in both the SMI interpolation method and RLS interpolation method, and these methods can be applied practically. (C) 2000 Scripta Technica.

关键词： land mobile communication cochannel interference adaptive array

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An SDR-Based Real-Time Testbed for GNSS adaptive array Anti-Jamming Algorithms Accelerated by GPU

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SENSORS 2016年第3期16卷 356-356页

作者： Xu, Hailong Cui, Xiaowei Lu, Mingquan Tsinghua Univ Dept Elect Engn Weiqing Bldg Beijing 100084 Peoples R China

Nowadays, software-defined radio (SDR) has become a common approach to evaluate new algorithms. However, in the field of Global Navigation Satellite System (GNSS) adaptive array anti-jamming, previous work has been limited due to the high computational power demanded by adaptive algorithms, and often lack flexibility and configurability. In this paper, the design and implementation of an SDR-based real-time testbed for GNSS adaptive array anti-jamming accelerated by a Graphics Processing Unit (GPU) are documented. This testbed highlights itself as a feature-rich and extendible platform with great flexibility and configurability, as well as high computational performance. Both Space-Time adaptive Processing (STAP) and Space-Frequency adaptive Processing (SFAP) are implemented with a wide range of parameters. Raw data from as many as eight antenna elements can be processed in real-time in either an adaptive nulling or beamforming mode. To fully take advantage of the parallelism resource provided by the GPU, a batched method in programming is proposed. Tests and experiments are conducted to evaluate both the computational and anti-jamming performance. This platform can be used for research and prototyping, as well as a real product in certain applications.

关键词： beamforming Space-Time adaptive Processing (STAP) nulling software-define radio (SDR) Global Navigation Satellite System (GNSS) anti-jamming adaptive array Space-Frequency adaptive Processing (SFAP)

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adaptive ANTENNA-array FOR DIRECTION-OF-ARRIVAL ESTIMATION UTILIZING THE CONJUGATE-GRADIENT METHOD

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SIGNAL PROCESSING 1995年第3期45卷 313-327页

作者： CHOI, S SARKAR, TK CHOI, J Department of Electronic Communication Hanyang University 17 Haengdang Sungdong Seoul 133-791 South Korea Department of Electrical and Computer Engineering Syracuse University Syracuse NY 13244-1240 USA Department of Radio Science and Engineering Hanyang University 17 Haengdang Sungdong Seoul 133-791 South Korea

This paper proposes two alternative techniques for the Direction-of-Arrival (DOA) estimation. Both techniques utilize the respective modifications of the conjugate gradient method (CGM) for iteratively finding the weight vector which is orthogonal to the signal subspace. In the first method, an eigenvector corresponding to the smallest eigenvalue is computed by minimizing the Rayleigh quotient of the full complex-valued autocovariance matrix. In the second method, a vector which is orthogonal to the signal subspace is computed directly from the signal matrix by finding a set of weights that minimizes the signal power at the array output. The performances of the proposed techniques are compared to that of the conventional eigen-decomposition (ED) method in terms of angle resolution for a given signal-to-noise ratio (SNR) with a preset number of snapshots in an observation interval. The standard deviation of angle dispersions is also encountered in measuring the array performance when a large number of inseparable signal components are involved in each cluster of the array inputs, From our computer simulations, we found that the proposed techniques in general result in comparable performances to the conventional ED method. The superiority of the suggested procedures becomes evident in adverse signal environments where the detection of the number of array inputs cannot be obtained successfully, for the proposed techniques are performed independently of the detection procedure.

关键词： adaptive array DIRECTION-OF-ARRIVAL ESTIMATION CONJUGATE GRADIENT METHOD ORTHOGONALITY DISPERSED SIGNALS

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A new, low-cost, switched beam and fully adaptive antenna array for 2.4 GHz ISM applications

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2007年第9期55卷 2502-2508页

作者： Mitilineos, Stelios A. Capsalis, Christos N. Natl Tech Univ Athens Sch Elect & Comp Engn Div Informat Transmiss Syst & Mat Technol GR-15773 Athens Greece

A new, low-cost, switched-beam and fully adaptive antenna array suitable for 2.4 GHz ISM applications is proposed in this paper. The array comprises of four elements, equal in number receiving RF and IF components, as well as a microcontroller based unit which is responsible for the control of the array. The array is designed with the aid of a custom genetic algorithm, while measurements results are presented indicating consistency between design and implementation. In addition, multipath fading mitigation capability of the array is demonstrated via channel measurements results.

关键词： adaptive array analog beamforming multipath fading switched-beam array 2.4 GHz ISM applications

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A practical approach to compensate for the mutual coupling effect in an adaptive dipole array

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2004年第5期52卷 1262-1269页

作者： Hui, HT Nanyang Technol Univ Singapore 639798 Singapore

A new method is introduced for the compensation of the mutual coupling effect of a linear adaptive dipole array employed in adaptive nulling of interference signals. The new method adopts a practical approach in that it needs only the measured voltages across the antenna terminal loads and an estimated current distribution for the calculation of the mutual impedances. The mutual impedance is defined and calculated differently from the conventional method and the results are more effective to remove the mutual coupling effect. The new method does not require the knowledge of the elevation angles of the signal of interest (SOI) and the interferences and still works if the elevation angles of the SOI and the interferences do not deviate, too much from the horizontal direction. This increases the capability of the array to work in three-dimensional signal environments. Computer simulations for a number of rather extreme signal environments have been carried out to testify the robustness and the capability of the new method.

关键词： adaptive array adaptive nulling mutual coupling mutual impedance

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Robust adaptive Microphone array with Mainlobe and Response Ripple Control

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JOURNAL OF SIGNAL PROCESSING SYSTEMS FOR SIGNAL IMAGE AND VIDEO TECHNOLOGY 2011年第3期63卷 301-313页

作者： Yu, Zhu Liang Gu, Zhenghui Ser, Wee Er, Meng Hwa Li, Yuanqing S China Univ Technol Coll Automat Sci & Engn Guangzhou Guangdong Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore Singapore

Many existing adaptive beamformers possess robustness against arbitrary array steering vector (ASV) mismatches within presumed uncertainty set. However, when the array facing a large steering direction error, their performance degrade significantly since the uncertainty in steering direction generally gives rise to an outstanding mismatch in ASV. In the applications of microphone array, large steering direction error is often unavoidable because of the motion of target speaker. Meanwhile, in addition to conventional adaptive beamformers, microphone array also requests a controlled frequency response to target signal. In this paper, we propose a new adaptive microphone array implemented in frequency domain with controlled mainlobe and frequency response. A compact ASV uncertainty set explicitly modelling steering direction error and the other arbitrary ASV errors is exploited to derive beamformer with robust constraints on array magnitude response. Numerical results show that the proposed microphone array not only produces large controlled robust response region and robust frequency response, but also achieves high performance in SINR enhancement.

关键词： Microphone array Robust adaptive beamforming adaptive array Constraints on magnitude response

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adaptive antenna array assisted dynamic channel allocation techniques

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2001年第2期19卷 305-311页

作者： Blogh, JS Cherriman, PJ Hanzo, L Univ Southampton Dept Elect & Comp Sci Southampton SO17 1BJ Hants England

The performance of base station adaptive antenna arrays (AAAs) is investigated in conjunction with fixed channel allocation (FCA) and dynamic channel allocation (DCA) schemes. Locally distributed DCA arrangements are studied and benchmarked against standard FCA, in the context of bath line-of-sight (LOS) and multipath propagation environments. One-, two-, four-, and eight-element AAAs are employed using the sample matrix inversion (SMI) beamforming algorithm, in both the up- and the downlink. In most investigated scenarios, the locally optimized least interference algorithm (LOLIA) exhibited the best overall compromise in terms of a set of combined metrics, such as the forced termination probability, new call blocking probability, and the probability of a low quality access.

关键词： adaptive antennas adaptive array beamforming dynamic channel allocation (DCA) network capacity wireless networks

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