論文 - 眞田　幸俊

Downlink Performance of MRT-BD in Multiuser Massive MIMO with Low Resolution ADCs

Gao P., Sanada Y.

IEEE 5G World Forum, 5GWF 2018 - Conference Proceedings （IEEE 5G World Forum, 5GWF 2018 - Conference Proceedings）     52 - 59 2018年10月

ISSN  9781538649824

　概要を見る

© 2018 IEEE. The multiuser massive MIMO (multi-input multi-output) system using the low-resolution analog-to-digital converters (ADCs) in the uplink is to realize low cost and power consumption demands, which, however, reduce the signal quality. Beamforming as a signal processing technique can supply high throughputs in the MIMO systems. In this paper, we investigate the robustness of low-resolution ADCs against the interference among the different streams in the uplink and the different users in downlink systems respectively, and propose the maximum ratio transmission - block diagonalization (MRT-BD) scheme as a kind of beamforming to evaluate the effects of low-resolution ADCs in the full digital massive MIMO system. The preliminary conclusion is that the MRT-BD scheme achieves our anticipation to make the rate achievable, even more than it in the infinite-resolution (no quantization) of BD case can be approached using ADCs with only a few bits of resolution.

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Low Complexity Metric Function for Gibbs Sampling MIMO Detection

Kobayashi Y., Sanada Y.

IEEE Vehicular Technology Conference （IEEE Vehicular Technology Conference）  2018-August 2018年07月

ISSN  9781538663585

　概要を見る

In this paper, a metric function for Gibbs sampling multiple-input multiple-output (MIMO) detection is proposed. In conventional Gibbs sampling MIMO detection, an exponential function is used in the calculation of a metric for the selection of candidate symbols. However, the exponential function can be implemented by a look-up table and may require a large amount of memory. This paper proposes a metric function based on a simple fraction. The proposed metric substitutes the exponential function though it increases the number of multiplication operations. It is shown by numerical results obtained through computer simulation that the proposed metric function improves the performance under a high signal-to-noise ratio condition in a large scale MIMO system since its curve is close to that of the exponential function when an input metric distance approaches to zero.

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System Throughput Analysis on Using Joint Detection in Distributed Antenna System

Ishikawa H., Sanada Y.

IEEE Vehicular Technology Conference （IEEE Vehicular Technology Conference）  2018-August 2018年07月

ISSN  9781538663585

　概要を見る

Throughput analysis of the usage of joint maximum-likelihood detection (MLD) in a distributed antenna system (DAS) with multiple mobile terminal scheduling is evaluated in this paper. In DAS, mobile terminals are closer to desired antennas which improves system throughput and increases frequency utilization efficiency. However, since there are more antennas in a cell, interference can occur between transmitted signals from the antennas when multiple mobile terminals are scheduled. Therefore, we propose a novel mobile terminal scheduling method and the use of joint MLD to reduce the effects of interference. A system level simulation shows that the usage of joint MLD in densely packed DAS provides better system throughput.

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Precoder Design Algorithm for Hybrid MIMO System with Discrete Phase Shifters and D/A Converters

Tamate D., Sanada Y.

IEEE Vehicular Technology Conference （IEEE Vehicular Technology Conference）  2018-August 2018年07月

ISSN  9781538663585

　概要を見る

In this paper, a precoder design algorithm using Gibbs sampling for hybrid multiple-input multiple-output (MIMO) systems is proposed. The hybrid MIMO systems are expected to be implemented in high frequency bands. To reduce power consumption and increase the bandwidth of a transmit signal, the number of phase shifters and the number of quatntization levels in digital-analog (D/A) converters have to be limited. A baseband precoder needs to take the effect of quantization into account. Owing to the quantization, it is difficult for a conventional precoder design algorithm with orthogonal matching pursuit (OMP) to reach the optimal solution. On the other hand, the proposed precoder design algorithm using Gibbs sampling is robust to quantization errors. Numerical results obtained through computer simulation show that the proposed algorithm achieves spectral efficiency of 50 bit/s/Hz at a signal-to-noise ration of 20 dB for a quantization level of 24 on an independent Rayleigh fading channel.

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Special Section on Communication Quality in Wireless Networks FOREWORD

Sanada Yukitoshi

IEICE TRANSACTIONS ON COMMUNICATIONS E101B （ 7 ） 1522 - 1522 2018年07月

ISSN  0916-8516

Low Complexity Log-Likelihood Ratio Calculation Scheme with Bit Shifts and Summations

Y. Aoki, K. Matsugi, and Y. Sanada

IEICE Trans. on Communications E101-B （ 3 ） 731 - 739 2018年03月

研究論文（学術雑誌）, 共著, 査読有り

Transmit Beam Selection Scheme for Massive MIMO using Expected Beam Responses

KUBO Yoshihito, SANADA Yukitoshi

IEICE Transactions on Communications （一般社団法人 電子情報通信学会）  E102B （ 4 ） 913 - 920 2018年

ISSN  0916-8516

　概要を見る

<p>Massive multiple-input multiple-output (MIMO) realizes simultaneous transmission to a large number of mobile stations (MSs) and improves frequency utilization efficiency. It is drawing attention as the key technology of the fifth-generation (5G) mobile communication systems. The 5G system is going to be implemented in a high frequency band and massive MIMO beamforming (BF) is applied to compensate propagation loss. In the conventional BF scheme, a transmit beam is selected based on the power of received signals over subcarriers. The signal on a different subcarrier is transmitted with a different directivity. To improve the accuracy of beam selection, this paper proposes a transmit beam selection scheme for massive MIMO. The proposed scheme calculates the expected responses of the signals over the subcarriers based on the relative directivity between a base station (BS) and a MS. The MS calculates the correlation between the received signals and each of the expected response sequences. It then selects the beam with the highest correlation value. It is shown in this paper that the proposed scheme can improve the average signal-to-noise ratio of a received signal by about 1.5dB as compared with that of the power based search scheme. It is also shown that the proposed scheme with limited response coefficients can reduce the computational complexity by a factor of 1/100 while it still increases the average SNR by about 1.0dB.</p>

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FOREWORD

SANADA Yukitoshi

IEICE Transactions on Communications （一般社団法人 電子情報通信学会）  101 （ 7 ） 1522 - 1522 2018年

ISSN  0916-8516

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Expanded Precoding Index Modulation for MIMO System

NIN Yasunori, SANADA Yukitoshi, KIMURA Ryota, MATSUDA Hiroki, SAWAI Ryo

IEICE Transactions on Communications （一般社団法人 電子情報通信学会）  E102B （ 4 ） 921 - 929 2018年

ISSN  0916-8516

　概要を見る

<p>Index modulation (IM) is receiving attention because of its high energy efficiency. In precoding index modulation (PIM), some of the data bits are used for the modulation of symbols and the rest are used for the selection of precoding coefficients. In conventional PIM, the precoding matrices are orthogonal and unitary. In the proposed PIM, the number of the columns of the precoding matrix is expanded more than that of the rows. Because of the expanded precoding matrices, the number of data bits used for the selection of precoding coefficients is increased. As a result, a code rate can be reduced compared to that of the conventional PIM and the number of candidate constellation points for demodulation can be decreased as compared to that of a multiple-input multiple-output MIMO system under the same throughput. Numerical results obtained through computer simulation show that the proposed PIM with QPSK symbols improves the performance by about 2.5 dB at a bit error rate of 10^-3 as compared to overloaded MIMO with 16QAM symbols for two transmit antennas and one receive antenna. It also achieves about 3.5 dB better performance than the conventional PIM under the same antenna condition. Furthermore, the optimum number of index modulation bits is found by the simulation for the proposed PIM. In addition, the PIM scheme reduces demodulation complexity by a factor of 32 as compared to that of the MIMO under specific modulation parameters.</p>

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Timing Synchronization Performance of Preamble Signal with Orthogonal Frequency Multiplexed Data Signal in the Presence of Frequency Offset

眞田 幸俊

Wireless Personal Communications 96 （ 4 ） 5499 - 5514 2017年10月

研究論文（学術雑誌）, 共著, 査読有り

Correlation Reduction Precoding for Joint Decoding in Overloaded MIMO-OFDM System on Rician Channel

T. Yabe and Y. Sanada

Wireless Personal Communications 96 （ 3 ） 3785 - 3798 2017年10月

研究論文（学術雑誌）, 共著, 査読有り

Cyclic Delay Diversity with Phase Shift in Low Rate SC-FDMA Uplink

眞田 幸俊

Wireless Personal Communications 96 （ 4 ） 5743 - 5755 2017年10月

研究論文（学術雑誌）, 共著, 査読有り

Performance Comparison of Overloaded MIMO System with and without Antenna Selection

Y. Nin, H. Matsuoka, and Y. Sanada

IEICE Trans. on Communications E100-B （ 5 ） 762 - 770 2017年02月

研究論文（学術雑誌）, 共著, 査読有り

Throughput Performance of Non-orthogonal Multiple Access with Joint Detection in Far User,

T. Yazaki and Y. Sanada

IEICE Trans. on Communications E100-B （ 2 ） 344 - 353 2017年02月

研究論文（学術雑誌）, 共著, 査読有り

Ricianフェージング環境におけるターボ符号とプレコーディ ング係数を用いた過負荷MIMO-OFDMシステムの特性検討

宮城 裕一，眞田 幸俊

映像情報メディア学会誌 71 （ 2 ） 68 - 73 2017年02月

研究論文（学術雑誌）, 査読有り

Joint Turbo Decoding for Overloaded MIMO-OFDM Systems

I. Shubhi and Y. Sanada

IEEE Trans. on Vehicular Technology 66 （ 1 ） 433 - 442 2017年01月

研究論文（学術雑誌）, 共著, 査読有り

Joint Maximum Likelihood Detection in Far User of Non-orthogonal Multiple Access

K. Ando and Y. Sanada

IEICE Trans. on Communications E100-B （ 1 ） 177 - 186 2017年01月

研究論文（学術雑誌）, 共著, 査読有り

Shift Estimation with Delayed Correlation Cyclic-Selectinve Mapping PAPR Reduction in OFDM System

P. D. Pamungkasari and Y. Sanada

Wireless Personal Communications, 91 （ 2 ） 739 - 753 2016年11月

研究論文（学術雑誌）, 査読有り

Effect of Signal Cancelation in Far User on Non-orthogonal Multiple Access Downlink

T. Yazaki and Y．Sanada

Wireless Personal Communications 89 （ 4 ） 1203 - 1219 2016年08月

研究論文（学術雑誌）, 共著, 査読有り

Pseudo Distance for Trellis Coded Modulation in Overloaded MIMO OFDM With Sphere Decoding

I. Shubhi and Y. Sanada

Trans. on Communications E99-B （ 3 ） 723 - 731 2016年03月

研究論文（学術雑誌）, 共著, 査読有り