研究者詳細 - 田野　哲

論文 - 田野　哲

分割表示 199 件中 121 - 140 件目／全件表示 >>

Difference Analysis in IEEE 802.11 DCF 査読

Daisuke Umehara, Hidekazu Murata, Satoshi Denno

2015 10th Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT) 2015年

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, a simple and accurate estimation on performance of the original IEEE 802.11 distributed coordination function (DCF) is presented. The performances obtained from the Bianchi's analytical model of the IEEE 802.11 DCF are compensated by means of (1) the number of consecutive successful transmissions and (2) the deferred slot time. The compensated performances including throughput, packet loss rate, and the average number of transmissions approximate to the simulation results with a high degree of accuracy under a number of conditions even when the minimum contention window is small. The analytical and simulation results show us the possibility of performance improvement by the sender priority.

Web of Science

researchmap

Transmit beamforming with DOA estimation in fast fading channels with AOA spread 査読

Satoshi Denno, Shigeru Tomisato, Masaharu Hata, Tatsuo Furuno, Yasuhiro Oda

2014 International Symposium on Antennas and Propagation Conference Proceedings 2014年12月

Iterative SVD-based frequency offset estimation with decorrelation for wireless sensor networks 査読

Satoshi Denno, Masataka Hasebe, Shigeru Tomisato, Masaharu Hata

2014 International Symposium on Wireless Personal Multimedia Communications (WPMC) 2014年9月

A non-linear distortion noise power control method for multi-band OFDM transmission 査読

Shohei Masaki, Shigeru Tomisato, Satoshi Denno, Masaharu Hata, Tatsuo Furuno, and Yasuhiro Oda

Proc. of the 17th International Symposium on Wireless Personal Multimedia Communications, WPMC 2014 748 - 753 2014年

A Virtual Channel Detector for Iterative Receiver in Overloaded MIMO OFDM Systems 査読

Satoshi Denno, Akihito Taya, Masahiro Morikura

2014 8TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Iterative MIMO receivers with virtual channel are known to outperform linear detectors in overloaded multiple-input multiple-output systems with orthogonal-frequency division multiplex (MIMO-OFDM). This paper proposes a novel virtual channel detector that enables iterative MIMO receivers to achieve superior performance to the conventional receivers. Moreover, this paper proposes a novel signal estimation technique named as "extended maximum a posteriori probability (MAP) estimation" to select more reliable virtual channel. The proposed technique estimates the virtual channel with not only the a priori information on the virtual channels but also that on the real signals. The performance of the proposed detector with the extended MAP estimation is verified in a 6 x 2 MIMO OFDM system where the Turbo code is applied. The receiver with the proposed detector achieves much better performance than the conventional receivers. Actually, the proposed detector enables the MIMO receiver to achieve a gain of 3.0 dB at the BER of 10(-5), compared with conventional receivers with virtual channels, e.g., the soft input soft output (SISO) MAP detector with the same Turbo decoder. It is confirmed that the proposed receiver has by about one-fifth less complexity than the receiver with the SISO MAP MIMO detector.

DOI： 10.1109/ICSPCS.2014.7021069

Web of Science

researchmap

Complexity Reduced Lattice-Reduction-Aided MIMO Receiver with Virtual Channel Detection 査読

Shogo Yoshikawa, Satoshi Denno, Masahiro Morikura

IEICE TRANSACTIONS ON COMMUNICATIONS E96B ( 1 ) 263 - 270 2013年1月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

This paper proposes a lattice-reduction-aided MIMO-OFDM receiver with virtual channels; the receiver enables an increase in the downlink transmission speed for a user where the number of transmit antennas is considerably higher than that of the receive antennas. However, the receiver has a higher computational complexity than conventional lattice-reduction-aided MIMO receivers. Accordingly, we also propose novel techniques to reduce the computational complexity for the lattice-reduction-aided MIMO receivers with virtual channels. The proposed MIMO receiver achieves superior performance in 10 x 2 MIMO-OFDM systems. Furthermore, the proposed techniques are shown to reduce the computational complexity to approximately 40% of the original configuration in the 10 x 2 MIMO-OFDM systems.

DOI： 10.1587/transcom.E96.B.263

Web of Science

researchmap

Software Radio-Based Distributed Multi-User MIMO Testbed: Towards Green Wireless Communications 査読

Hidekazu Murata, Susumu Yoshida, Koji Yamamoto, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E96A ( 1 ) 247 - 254 2013年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

The present paper introduces a prototype design and experimental results for a multi-user MIMO linear precoding system. A base station and two mobile stations are implemented by taking full advantage of the software-defined radio. The base station consists of general purpose signal analyzers and signal generators controlled by a personal computer. Universal software radio peripherals are used as mobile stations. Linear spatial precoding and a simple two-way channel estimation technique are adopted in this experimental system. In-lab and field transmission experiments are carried out, and the bit error rate performance is evaluated. The impact of the channel estimation error under average channel gain discrepancy between two mobile stations is analyzed through computer simulations. Channel estimation error is shown to have a greater influence on the mobile station with the greater average channel gain.

DOI： 10.1587/transfun.E96.A.247

Web of Science

CiNii Article

researchmap

Frequency Domain Imbalance Estimation in Heterodyne Multimode/Band Receivers with Baseband Automatic Gain Control 査読

Satoshi Denno, Ke Liu, Tatsuo Furuno, Masahiro Morikura

IEICE TRANSACTIONS ON COMMUNICATIONS E96B ( 1 ) 271 - 280 2013年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

This paper proposes a novel scheme called as "frequency domain imbalance estimation" that estimates the imbalance of the Hilbert transformer in heterodyne multimode/band receivers with baseband automatic gain control (AGC). The proposed scheme uses correlation matrices in the frequency domain. This enables the receivers to keep high transmission performance in spite of the imbalance of the analog Hilbert transformer, by offsetting the imbalance. Moreover, the baseband AGC relaxes the requirement of the baseband AID converter. The performance of imbalance estimation and imbalance cancellation is verified by computer simulation. As a result, it is shown that the proposed scheme not only estimates the imbalance of Hilbert transformer with extremely high precision, but also cancels the image-band interference such that it achieves the theoretical performance.

DOI： 10.1587/transcom.E96.B.271

Web of Science

CiNii Article

researchmap

Iterative frequency offset estimation based on singular value decomposition

Masataka Hasebe, Satoshi Denno, Shigeru Tomisato, Masaharu Hata

Proc. of 2013 International Symposium on Intelligent Signal Processing and Communication Systems, ISPACS 2013 125 - 130 2013年

Indoor Experiment of Multi-User MIMO User Selection Algorithm Based on Chordal Distance 査読

Masato Taniguchi, Hidekazu Murata, Susumu Yoshida, Koji Yamamoto, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

2013 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM) 3959 - 3964 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A transmission experiment of a multi-user MIMO system with user selection and linear spatial precoding is conducted and the results are reported. As a low-complexity user selection algorithm, the chordal distance-based user selection (CDUS) algorithm is employed. The testbed used in the experiment is implemented by taking full advantage of the software-defined radio. An amplify-and-forward-based simple channel estimation method is adopted. As a result of the experiment in a conference room, the CDUS algorithm improved both the power efficiency and the interference suppression accuracy compared to the round-robin user selection.

DOI： 10.1109/GLOCOM.2013.6831692

Web of Science

researchmap

A reduced-complexity heterodyne multiband MIMO receiver with estimation of analog devices imperfection in a baseband feedback loop 査読

Tomoya Ohta, Satoshi Denno, Masahiro Morikura

IEICE Transactions on Communications E96-B ( 6 ) 1540 - 1550 2013年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Electronics, Information and Communication, Engineers, IEICE

This paper proposes a reduced-complexity multiband multiple-input multiple-output (MIMO) receiver that can be used in cognitive radios. The proposed receiver uses heterodyne reception implemented with a wide-passband band-pass filter in the radio frequency (RF) stage. When an RF Hilbert transformer is utilized in the receiver, image-band interference occurs because of the transformer's imperfections. Thus, the imperfection of the Hilbert transformer is corrected in the intermediate frequency (IF) stage to reduce the hardware complexity. First, the proposed receiver estimates the channel impulse response in the presence of the strong image-band interference signals. Next, the coefficients are calculated for the correction of the imperfection at the IF stage, and are fed back to the IF stage through a feedback loop. However, the imperfection caused by the digital-to-analog (D/A) converter and the baseband amplifier in the feedback loop corrupts the coefficients on the way back to the IF stage. Therefore, the proposed receiver corrects the imperfection of the analog devices in the feedback loop. The performance of the proposed receiver is verified by using computer simulations. The proposed receiver can maintain its performance even in the presence of strong image-band interference signals and imperfection of the analog devices in the feedback loop. In addition, this paper also reveals the condition for rapid convergence. Copyright © 2013 The Institute of Electronics.

DOI： 10.1587/transcom.E96.B.1540

Scopus

CiNii Article

researchmap

A low complexity heterodyne multiband MIMO receiver with baseband automatic gain control 査読

Tomoya Ohta, Satoshi Denno, Masahiro Morikura

IEICE Transactions on Communications E96-B ( 12 ) 3124 - 3134 2013年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Institute of Electronics, Information and Communication, Engineers, IEICE

This paper proposes a novel heterodyne multiband multiple-input multiple-output (MIMO) receiver with baseband automatic gain control (AGC) for cognitive radios. The proposed receiver uses heterodyne reception implemented with a wide-passband band-pass filter in the radio frequency (RF) stage to be able to receive signals in arbitrary frequency bands. Even when an RF Hilbert transformer is utilized in the receiver, image-band interference occurs due to the imperfection of the Hilbert transformer. In the receiver, analog baseband AGC is introduced to prevent the baseband signals exceeding the voltage reference of analogto- digital converters (ADCs). This paper proposes a novel technique to estimate the imperfection of the Hilbert transformer in the heterodyne multiband MIMO receiver with baseband AGC. The proposed technique estimates not only the imperfection of the Hilbert transformer but also the AGC gain ratio, and analog devices imperfection in the feedback loop, which enables to offset the imperfection of the Hilbert transformer. The performance of the proposed receiver is verified by using computer simulations. As a result, the required resolution of the ADC is 9 bits in the proposed receiver. Moreover, the proposed receiver has less computational complexity than that with the baseband interference cancellation unless a frequency band is changed every 9 packets or less. Copyright © 2013 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transcom.E96.B.3124

Scopus

CiNii Article

researchmap

A Convolutional Coded XOR Physical Layer Network Coding with Unitary Precoding in Wireless Bidirectional Relay Networks 査読

Satoshi Denno, Daisuke Umehara

2013 7TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Physical layer network coding is able to improve frequency utilization efficiency in bi-directional wireless communications via a relay. This paper proposes a novel error correction scheme for physical layer XOR network coding. The proposed scheme not only improves transmission performance but also to reduce complexity at the relay. The proposed scheme applies a unitary precoding to offset phase rotation in the channel by exploiting the reciprocity between channels in the uplink and the downlink in systems with time division duplex (TDD). Moreover, a novel complexity reduced maximum likelihood detection technique is applied in the proposed scheme. It is evaluated by computer simulation that the proposed scheme attains a gain of 8dB at BER=10(-5) compared with AF network coding in a system with the use of OFDM.

Web of Science

researchmap

Experimental Comparison of Linear Prediction Schemes for Multi-User MIMO Systems 査読

Toshiki Tanaka, Hidekazu Murata, Susumu Yoshida, Koji Yamamoto, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

2013 11TH INTERNATIONAL SYMPOSIUM ON MODELING & OPTIMIZATION IN MOBILE, AD HOC & WIRELESS NETWORKS (WIOPT) 95 - 100 2013年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In a multi-user multiple-input multiple-output (MU-MIMO) system, zero-forcing precoding can completely eliminates inter-user interference when the perfect channel state information is available at the base station. However, in time-varying channels, the transmission performance of MU-MIMO systems is severely degraded due to inter-user interference. In this paper, channel prediction is employed for channel tracking, and in-lab experiments are carried out to confirm its performance. The bit error rate (BER) performance is measured and compared with the computer simulation results. Both in-lab experiments and the computer simulations show that channel prediction improves the BER performance.

Web of Science

researchmap

Complexity Reduced Lattice-Reduction-Aided MIMO Receiver with Virtual Channel Detection 査読

田野哲

IEICE Transaction on Communications E96-B 247 - 254 2012年12月

A Virtual Layered Successive Detector with Adaptive Transmit Signal Phase Rotation for QAM 査読

DENNO Satoshi, IMAMURA Jun, MORIKURA Masahiro

IEICE transactions on communications 95 ( 10 ) 3232 - 3241 2012年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：The Institute of Electronics, Information and Communication Engineers

This paper proposes a virtual layered successive detector with adaptive transmit signal phase rotation for quadrature amplitude modulation (QAM) that enables high speed communication even in downlinks of wireless communication systems. It is shown that the detection performance is degraded when the eigenvalue of a virtual channel becomes close to the power of the additive white Gaussian noise (AWGN). Therefore, adaptive transmit signal phase rotation is introduced for the detector to improve the transmission performance. For the transmit phase rotation, three techniques to search the rotation angles are proposed, which can reduce the feedback information from the receiver to the transmitter. Among the three proposed techniques, the technique called "iterative variable step step search" is shown to achieve the best performance. Actually, it is confirmed by computer simulation that the variable step search makes the detector attain about 17dB of a gain at the bit error rate (BER) of 10^-5 in 4×2 multiple-input-multiple-output (MIMO) systems.

DOI： 10.1587/transcom.E95.B.3232

CiNii Article

CiNii Books

researchmap

A Least Bit Error Rate Adaptive Array for MultiLevel Modulations 査読

DENNO Satoshi, UMEHARA Daisuke, MORIKURA Masahiro

IEICE transactions on communications 95 ( 1 ) 69 - 76 2012年1月

This paper proposes an adaptive algorithm for adaptive arrays that minimizes the bit error rate (BER) of the array output signals in radio communication systems with the use of multilevel modulation signals. In particular, amplitude phase shift keying (APSK) is used as one type of multilevel modulations in this paper. Simultaneous non-linear equations that are satisfied by the optimum weight vector of the proposed algorithm are derived and used for theoretical analyze of the performance of the adaptive array based on the proposed algorithm. As a result of the theoretical analysis, it can be shown that the proposed adaptive array improves the carrier to interference ratio of the array output signal without taking advantage of the nulls. Furthermore, it is confirmed that the result of the theoretical analysis agrees with that of computer simulation. When the number of the received antenna is less than that of the received signals, the adaptive array based on the proposed algorithm is verified to achieve much better performance then that based on the least mean square (LMS) algorithm.

DOI： 10.1587/transcom.E95.B.69

CiNii Article

CiNii Books

researchmap

A Virtual Successive Detection for Cooperative MU-MIMO Systems with Reduced CSI 査読

田野哲

Proceedings of the IEEE 75th Vehicular Technology Conference 1 1 - 5 2012年

Field Experiments of Linearly Precoded Multi-User MIMO System at 5 GHz Band 査読

Masato Taniguchi, Hidekazu Murata, Susumu Yoshida, Koji Yamamoto, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

2012 IEEE VEHICULAR TECHNOLOGY CONFERENCE (VTC FALL) 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, implementation of a multi-user MIMO experimental system is presented. Linear spatial precoding and a simple two-way channel estimation technique are adopted in the experimental system. In-lab and field transmission experiments are carried out and the performance is evaluated. The impact of channel estimation error under average channel gain discrepancy between two mobile stations is analyzed by means of computer simulation. It is shown that channel estimation error has a greater influence on the mobile station with greater average channel gain.

Web of Science

researchmap

Partitioned Vector Quantization for MU-MIMO Downlink Broadcasting 査読

Mirza Golam Kibria, Hidekazu Murata, Susumu Yoshida, Koji Yamamoto, Daisuke Umehara, Satoshi Denno, Masahiro Morikura

2012 IEEE VEHICULAR TECHNOLOGY CONFERENCE (VTC FALL) 2012年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

A practical and efficient vector quantization called partitioned vector quantization (P-VQ) based non-linear precoder for MIMO downlink broadcasting channels has been analyzed in this paper. P-VQ has been found to be an efficient way of reducing the memory requirements and search complexity in conventional VQ systems, especially for large MIMO. Simulation results reveal that P-VQ technique can enhance the overall quantization performance in terms of achieved capacity, bit error rate (BER) at a cost of reasonable additional complexity under certain feedback budgets. Tomlinson-Harashima precoding (THP), a power and complexity efficient precoding technique along with data dependent vector perturbation (VP) has been employed to meet the power constraint requirements of our system. Least-square (LS) channel estimation is performed at the user terminals to acquire their channel state information (CSI).

Web of Science

researchmap

　前のページ - 次のページ　

<田野 哲>

論文 - 田野 哲

<田野　哲>

論文 - 田野　哲