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adaptive antenna-array UNDER DIRECTIONAL AND SPATIAL DERIVATIVE CONSTRAINTS

IEE PROCEEDINGS-H MICROWAVES antennaS AND PROPAGATION 1988年第6期135卷 414-419页

作者： ER, MH School of Electrical & Electronic Engineering Nanyang Technological Institute Singapore Singapore

The paper first examines the issue of the beampattern dependency on the choice of phase centre location, when a narrow band beamformer is subjected to directional and spatial derivative constraints. It is shown that the norm of the weight vectors for a zero-plus-first and zero-plus-first-plus-second derivative constrained beam-formers, under white noise conditions, is a quadratic and a quartic function of a parameter which specifies the phase centre location. The paper then presents a technique based on a power response approach, for deriving a new set of constraints for controlling the beampattern spatial derivates. The new set of constraints ensure that the array beam-pattern is independent of the choice of the phase centre co-ordinate origin. It is shown that for the first-order case, the constraint is linear, but for the second-order case, the constraint is quadratic. The paper then presents a technique for approximating the effect of the quadratic constraint by two linear constraints. It is shown that by using these two sets of linear constraints, the dependency of the beampattern on the choice of the phase centre co-ordinate origin cannot be totally eliminated, but the effect has been very much reduced. Finally, the paper presents a technique for optimising the beampattern with respect to the choice of the phase centre location, when the quadratic constraint is being approximated with linear con-straints. Numerical results showed that the optimised version has a better performance in terms of maintaining beamwidth broadening and capability of rejecting interferences.

关键词： quadratic constraint antenna theory antenna arrays directional constraints beampattern dependency antenna radiation patterns antenna phased arrays spatial derivative constraints adaptive antenna array narrow band beamformer linear constraints power response approach phase centre location antenna theory

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adaptive antenna array Based Non-Cooperative Co-Channel Interference Cancellation System for Ultrashort Wave Radios and Non-Ideality Analysis

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2024年第1期73卷 678-690页

作者： Cui, Zhongpu Li, Yaxing Ge, Songhu Zhang, Jiahao Zhang, Yunshuo Meng, Jin Naval Univ Engn Natl Key Lab Electromagnet Energy Wuhan 430033 Peoples R China

Interference cancellation holds great promising to suppress the non-cooperative interference. However, it is usually difficult to obtain an ideal copy of the non-cooperative interference since its statistical characteristics are unknown. A novel adaptive antenna array based non-cooperative co-channel interference cancellation system for ultrashort wave (USW) radios is proposed in this article. By adopting the auxiliary antenna array, the designed system realizes blind interference extraction from the received mixed signal based on the constrained maximum variance criterion. Then, the extracted interference is assigned as the reference signal to realize interference cancellation of the received signal in the reference antenna channel. Meanwhile, the non-ideality characteristics including nonlinearity and IQ imbalance in the receiver chain are taken into account. A widely linear least mean square (WLLMS) model based on Volterra series is introduced in the cancellation process. As a blind method, no extra reference signal and specified array structure are required in this proposed system. Simulation and experimental results validate the effectiveness of the proposed scheme, which implies comparatively strong practicality in non-cooperative co-channel interference cancellation for USW radios in engineering.

关键词： ultrashort wave (USW) radios adaptive antenna array adaptive interference extraction nonlinearity IQ imbalance widely-linear interference cancellation

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adaptive antenna array using real symmetric array covariance matrix

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ELECTRONICS LETTERS 2001年第7期37卷 405-406页

作者： Kim, K Saunders, SR Univ Surrey CCSR Guildford GU2 5XH Surrey England

A novel scheme using a real symmetric array covariance matrix for an adaptive antenna array in DS/CDMA is proposed. A real symmetric array covariance matrix is: estimated from a complex array covariance matrix using a unitary transformation and Toeplitz matrix approximation methods. Especially. the Hermitian Toeplitzation method nor only estimates persymmetric matrix form for a real symmetric array covariance matrix but also enhances the performance of the received signal by removing the undesired affect obtained from a complex array covariance matrix. Simulation results demonstrate rh;effectiveness of the proposed scheme.

关键词： Mobile radio systems adaptive antenna arrays Multiple access communication spread spectrum communication DS/CDMA antenna arrays adaptive antenna array Toeplitz matrix approximation symmetric array covariance matrix received signal Toeplitz matrices persymmetric matrix form unitary transformation code division multiple access land mobile radio covariance matrices

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adaptive antenna array with monopulse totally-different directional diagram

Adaptive antenna array with monopulse totally-different dire...

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Conference on Lasers for Measurements and Information Transfer 2006

作者： Popov, A. S. Balt State Tech Univ Voenmeh St Petersburg Russia

ISBN: (纸本)9780819467249

This paper is devoted for a monopulse system with adaptive cancellation of interferences usage in radars or radio connection systems. in article the directional characteristic and bearing characteristic of the monopulse angular discriminator is esteemed. It is designed on the basis of an adaptive antenna array (AAA). These characteristics can be called dynamic, as they were calculated at adaptive change of weighting coefficients AAA.

关键词： adaptive antenna array monopulse system totally-differential angular discriminator pelengation

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adaptive antenna array with weight and antenna space control

Adaptive Antenna Array with weight and antenna space control

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IEEE Wireless Communications and Networking Conference (IEEE WCNC)

作者： Umebayashi, Kenta Kimoto, Yoshimasa Tolli, Antti Tokyo Univ Agr & Technol Dept Elect & Elect Engn Tokyo Japan Univ Oulu Ctr Wireless Commun Oulu Finland

ISBN: (纸本)9781728131061

A typical adaptive antenna array based on weight control (AAA-W) with M antennas can suppress M - 1 interference signals. In this paper, we propose AAA based on not only weight but also antenna spacing control (AAA-WS) and investigate the basic performance of AAA-WS under the line-of-sight. At first, we show that AAA-WS with two antennas (M = 2) can sufficiently suppress more than two interference signals while the desired signal is enhanced. The inherent interference suppression capability of AAA-WS can be determined by the maximum antenna spacing and this fact is exhibited by analysis and Monte Carlo simulations. In addition, we will show that AAA-WS with two antennas can outperform AAA-W with more than two antennas. It is notable that the additional gain in AAA-WS compared to AAA-W can be around 18 dB.

关键词： adaptive antenna array antenna space control Beamforming Interference suppression Line of sight

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Combined effect of coherent adaptive antenna array diversity and SINR-based fast transmit power control in W-CDMA reverse link

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IEICE TRANSACTIONS ON COMMUNICATIONS 2001年第3期E84B卷 425-434页

作者： Tanaka, S Harada, A Ihara, T Sawahashi, M Adachi, F NTT DoCoMo Inc Wireless Res Labs Yokosuka Kanagawa 2398536 Japan Tohoku Univ Grad Sch Engn Dept Elect & Commun Engn Sendai Miyagi 9808579 Japan

This paper evaluates through laboratory and field experiments the combined effect of the coherent adaptive antenna array diversity (CAAAD) receiver and signal-to-interference plus background noise ratio (SINR)-based fast transmit power control (TPC) in order to improve performance beyond that of space diversity (SD) with maximal ratio combining (MRC) in all low-to-high signal-to-interference power ratio (SIR) channels in the W-CDMA reverse link. Although the previously proposed CAAAD receiver comprising an adaptive antenna array based on the minimum mean square error (MMSE) criterion and a coherent Rake combiner was very effective in suppressing interference in low SIR (interference is severe) channels, SD employing MRC in noise limited channels (high SIR) outperformed the CAAAD because of its uncorrelated reception of fading Variation due to its large antenna separation. The laboratory experimental results showed that the required average transmit signal energy per bit-to-background noise spectrum density (E-b/N-0) with the CAAAD receiver using fast TPC is lower than that with an SD receiver over a wide range of maximum Doppler frequency values from f(D) = 5Hz to 500Hz in a low-to-high SIR channel. The results of the field experiments also showed that combining CAAAD and fast TPC is a powerful means to reduce severe multiple access interference (MAI) from high rate users in a low-to-high SIR environment and is more effective than using the SD receiver with the same number of antennas, i.e., the measured BER was improved by approximately one order of magnitude, when the relative transmit power of the desired user was 8 dB with two antennas at the average received SIR at the antenna input of -12dB.

关键词： mobile communications W-CDMA adaptive antenna array fast transmit power control

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Fast two-step beam tracking algorithm of coherent adaptive antenna array diversity receiver in W-CDMA reverse link

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IEICE TRANSACTIONS ON COMMUNICATIONS 2001年第7期E84B卷 1835-1848页

作者： Ihara, T Tanaka, S Sawahashi, M Adachi, F NTT DoCoMo Inc Wireless Labs Yokosuka Kanagawa 2398536 Japan Tohoku Univ Grad Sch Engn Dept Elect & Commun Engn Sendai Miyagi 9808579 Japan

In wideband direct sequence code division multiple access (W-CDMA), employing an adaptive antenna array is a very, promising technique to reduce severe multiple access interference (MAI) especially from high rate users. This paper proposes a fast and accurate two-step beam tracking algorithm implemented in a pilot symbol-assisted coherent adaptive antenna array diversity (CAAAD) receiver and evaluates its performance both by computer simulation and laboratory experiments. In the proposed scheme, the receiver antenna weights are updated by using both the signal-to-interference power ratio (SIR) measurements employing multiple sets of antenna weights (MSAW) and an adaptive algorithm based on the minimum mean square error (MMSE) criterion, in which other sets: except for a original set of antenna, weights are simply generated by a original set. Computer simulation results show that antenna weights of a four-antenna CAAAD receiver using the proposed beam tracking algorithm tracks changes in the direction of arrival (DOA) of the desired user at up to 34.3 degrees/sec, which corresponds to 215 km/h at 100 m from a base station. Mif also confirm based on the experiments in a radio anechoic room that the generated antenna weights track the DOA changes up to 12.3 degrees:sec.

关键词： DS-CDMA adaptive antenna array beam tracking mobile radio communication

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Experiments on adaptive antenna array transmit diversity in W-CDMA forward link

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2002年第7期E85A卷 1612-1623页

作者： Harada, A Tanaka, S Sawahashi, M Adachi, F NTT DoCoMo Inc Wireless Res Labs Yokosuka Kanagawa 2398536 Japan Tohoku Univ Grad Sch Engn Dept Elect & Commun Engn Sendai Miyagi 9808579 Japan

This paper proposes adaptive antenna array transmit diversity (AAA-TD) in the W-CDMA forward link with frequency division duplexing (FDD), based on adaptively-generated receiver antenna weights in the reverse link, which only track the changes in the average signal-to-interference power ratio (SIR) and direction of arrival (DOA) but with the calibration of the phase/amplitude variations of the parallel RF receiver/transmitter circuits corresponding to the number of array antennas. The laboratory and field experimental results exploiting AAA-TD are presented to show the strong multipath interference (MPI) suppression effect especially from high-rate users with large transmission power. Laboratory experiments elucidate that by using AAA-TD with four antennas, the required transmitted SIR. before multiplying the transmitter antenna weights at the average BER of 10(-3) is decreased by approximately 13 dB compared to that with one omni-directional antenna transmitter. Field experiments also show that although an error floor above 10(-2) is observed with one omni-directional antenna. transmitter when the transmitted SIR is -12 dB due to severe MPI, no error floor is observed when employing 4-antenna AAA-TD and the loss of the required received signal power at the average BER. of 10(-3) from the single-user case is suppressed to below approximately 5 dB. Therefore, we show that AAA-TD is very effective in suppressing severe MPI especially from high rate users with large transmission power due to its adaptive main lobe and null steering.

关键词： adaptive antenna array DS-CDMA mobile radio

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Experiments on decision feedback type coherent adaptive antenna array diversity receiver in W-CDMA reverse link

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IEICE TRANSACTIONS ON COMMUNICATIONS 2001年第7期E84B卷 1849-1860页

作者： Tanaka, S Taoka, H Ihara, T Sawahashi, M NTT DoCoMo Inc Wireless Labs Yokosuka Kanagawa 2398536 Japan

This paper proposes a receiver antenna weight-updating algorithm using I/Q-code multiplexed pilot and decision feedback data symbols after channel decoding for both reference signal generation of the mean squared error (MSE) calculation and channel estimation (also for Rake combining) in the coherent adaptive antenna array diversity (CAAAD) receiver and investigates its performance, in order to decrease further the transmit power of a mobie station, thereby increasing system capacity in the wideband direct sequence code division multiple access (W-CDMA) reverse link. Experimental results show that the required transient E-b/N-0 for the average BER of 10(-3) with the CAAAD receiver using pilot and decision feedback data symbols after channel decoding both for reference signal generation and for channel estimation call be decreased by approximately 0.8 dB compared to when using only pilot symbols with convolutional coding or turbo coding, when the ratio of the target E-b/I-0 for fast transmit power control of the desired to interfering users is DeltaE(b)/I-0 = -12 dB. The results also elucidate that the required transmit E-b/N-0:, at the average BER of 10(-6) with turbo coding using the proposed decision feedback antenna weight-updating and channel estimation is smaller by approximately 0.5 dB than that using convolutional coding when the channel interleaving length is 20 msec for DeltaE(b)/I-0 = -12 dB.

关键词： DS-CDMA adaptive antenna array interference suppression decision feedback data

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Experimental evaluations on array antenna configuration of adaptive antenna array diversity receiver in W-CDMA reverse link

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2000年第11期E83A卷 2120-2128页

作者： Ihara, T Tanaka, S Harada, A Sawahashi, M Adachi, F NTT DoCoMo Inc Wireless Res Labs Yokosuka Kanagawa 2398536 Japan

This paper investigates the influence of the number of antennas, the angle difference between the direction of arrival (DOA) of the desired signal and those of interfering signals, and the antenna arrangement on the BER performance of the coherent adaptive antenna array diversity (CAAAD) receiver in the wideband DS-CDMA (W-CDMA) reverse link. Experiments assuming high-rate interfering users were conducted in a radio anechoic room using a three-sectored antenna with a 120-degree beam (maximum number of antennas was six). The experimental results showed that the degree to which the interference was suppressed from high-rate users of the CAAAD receiver was significantly increased by increasing the number of antennas, especially when the number of interfering users was larger than degree of freedom of the CAAAD. It was also verified that although the BER performance of the CAAAD receiver significantly improved compared to a single sectored antenna;the improvement remarkably decreased when the DOA difference between the desired signal and interfering signals was within approximately +/-10-15 degrees irrespective of the number of antennas. Finally. we show that the BER performance difference between the linear and conformal arrangements was small when using the three-sectored antenna.

关键词： mobile radio communication DS-CDMA adaptive antenna array interference suppressing

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