The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Fumiyuki Adachi - One of the best experts on this subject based on the ideXlab platform.
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on understanding of massive mimo beam forming from multi user joint transmit Receive Diversity principle
Vehicular Technology Conference, 2021Co-Authors: Fumiyuki Adachi, Ryo TakahashiAbstract:Massive MIMO beamforming is an essential technique for 5G and beyond 5G systems. In this paper, we try to give a theoretical foundation to the massive MIMO beamforming from the principle of a multi-user joint transmit-Receive Diversity (JTRD). Multi-user JTRD is designed to maximize each user’s composite MIMO channel gain. It is shown that multi-user JTRD using linear array at a base station (BS) is equivalent to full/hybrid beamforming. The Received signal-to-noise ratio (SNR) expression is derived for a given multi-user MIMO channel. Then, the 2-user link capacity in a Rayleigh fading environment is evaluated by Monte-Carlo numerical computation method.
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transmit fde weight design for single carrier space time block coded joint transmit Receive Diversity
International Conference on Information and Communication Security, 2013Co-Authors: Hiroyuki Miyazaki, Fumiyuki AdachiAbstract:Single-carrier (SC) transmission using frequency-domain space-time block coded joint transmit/Receive Diversity (FD-STBC-JTRD) combined with transmit frequency-domain equalization (FDE) obtains full spatial Diversity gain and frequency Diversity gain. Channel state information (CSI) is required only at transmitter for transmit FDE. In our previous study of SC FD-STBC-JTRD, single transmit FDE weight matrix was used. In this paper, noting that a sequence of data blocks is STBC encoded into a code-word composed of a new sequence of coded data blocks, we derive the optimal transmit FDE weight design. Multiple transmit FDE weight matrices, each associated with each coded block in a STBC code-word, are used unlike our previous transmit FDE weight design. Transmit FDE weight matrices are jointly optimized based on the minimization of the mean square error (MSE) between the transmitted signal before STBC encoding and the Received signal after STBC decoding. We show by theoretical analysis that the optimal transmit FDE weight design can achieve 1/RSTBC times higher signal-to-interference plus noise power ratio (SINR) than our previous design (single transmit FDE weight matrix), where RSTBC denotes the STBC coding rate. And then, we show, by computer simulation, the optimal transmit FDE weight design achieves better bit error rate (BER) performance than our previous design.
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downlink throughput performance of distributed antenna network using transmit Receive Diversity
Vehicular Technology Conference, 2011Co-Authors: Ryusuke Matsukawa, Tatsunori Obara, Kazuki Takeda, Fumiyuki AdachiAbstract:In this paper, we investigate how a distributed antenna network (DAN) offers better throughput performance than a conventional cellular network (CN). In DAN, a group of multiple antennas are distributed in each cell of the CN in order to mitigate the adverse effect of path loss. Moreover, antenna Diversity technique can make use of shadowing and multipath fading to improve the transmission performance due to a large spatial Diversity gain. In this paper, we consider frequency-domain space-time block coded-joint transmit/ Receive Diversity (FD-STBC-JTRD) for downlink transmission of single-carrier (SC) DAN. FD-STBC-JTRD uses frequency-domain pre-equalization (pre-FDE) instead of Receive FDE to keep the mobile terminal's complexity low, and achieves the full-Diversity gain. We show by computer simulation that the transmit power for achieving the required throughput can be significantly reduced compared to the conventional CN.
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single carrier distributed antenna network downlink using joint transmit Receive Diversity
International Conference on Conceptual Structures, 2010Co-Authors: Ryusuke Matsukawa, Tatsunori Obara, Kazuki Takeda, Fumiyuki AdachiAbstract:Single-carrier distributed antenna network (SC-DAN), in which a group of multiple antennas are distributed in a cell serve a user, can mitigate adverse impacts of path loss, shadowing loss and multipath fading. Frequency-domain space-time block coded-joint transmit/ Receive Diversity (FD-STBC-JTRD) is attractive for downlink transmission since an arbitrary number of distributed transmit antennas can be used. FD-STBC-JTRD requires the channel state information (CSI) only at the transmitter side and therefore, the complexity problem of mobile terminals can be alleviated. In this paper, we investigate, by computer simulation, the bit error rate (BER) distribution of the SC-DAN downlink. We discuss the impact of the number of distributed antennas involved in FD-STBC-JTRD on the BER outage probability.
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frequency domain space time block coded joint transmit Receive Diversity for direct sequence spread spectrum signal transmission
IEICE Transactions on Communications, 2007Co-Authors: Hiromichi Tomeba, Kazuaki Takeda, Fumiyuki AdachiAbstract:SUMMARY Recently, we proposed space-time block coded-joint transmit/Receive antenna Diversity (STBC-JTRD) for narrow band transmission in a frequency-nonselective fading channel; it allows an arbitrary number of transmit antennas while limiting the number of Receive antennas to 4. In this paper, we extend STBC-JTRD to the case of frequency-selective fading channels and propose frequency-domain STBC-JTRD for broadband direct sequence-spread spectrum (DSSS) signal transmission. A conditional bit error rate (BER) analysis is presented. The average BER performance in a frequency-selective Rayleigh fading is evaluated by MonteCarlo numerical computation method using the derived conditional BER and is confirmed by computer simulation of the signal transmission. Performance comparison between frequency-domain STBC-JTRD transmission and joint space-time transmit Diversity (STTD) and frequency-domain equalization (FDE) reception is also presented.
Wenyong Luo - One of the best experts on this subject based on the ideXlab platform.
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orbital angular momentum mode group multiplexed transmission over a graded index ring core fiber based on Receive Diversity and maximal ratio combining
Optics Express, 2018Co-Authors: Junwei Zhang, Guoxuan Zhu, Jie Liu, Jiangbo Zhu, Wenyong Luo, Yujie ChenAbstract:An orbital-angular-momentum (OAM) mode-group multiplexing (MGM) scheme using high-order mode groups (MGs) in a graded-index ring-core fiber (GIRCF) is proposed, in which a Receive-Diversity architecture is designed for each MG to suppress the mode partition noise resulting from random intra-group mode crosstalk. The signal-to-noise ratio (SNR) of the Received signals is further improved by a simple maximal ratio combining (MRC) technique on the Receiver side to efficiently take advantage of the Diversity gain of the Receiver. Intensity-modulated direct-detection (IM-DD) systems transmitting three OAM mode groups with total 100-Gb/s discrete multi-tone (DMT) signals over a 1-km GIRCF and two OAM mode groups with total 40-Gb/s DMT signals over an 18.4-km GIRCF are experimentally demonstrated, respectively, to confirm the feasibility of our proposed OAM-MGM scheme.
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orbital angular momentum mode group multiplexed transmission over a graded index ring core fiber based on Receive Diversity and maximal ratio combining
arXiv: Signal Processing, 2017Co-Authors: Junwei Zhang, Guoxuan Zhu, Jiangbo Zhu, Liu Jie, Wenyong LuoAbstract:An orbital-angular-momentum (OAM) mode-group multiplexing (MGM) scheme based on a graded-index ring-core fiber (GIRCF) is proposed, in which a single-input two-output (or Receive Diversity) architecture is designed for each MG channel and simple digital signal processing (DSP) is utilized to adaptively resist the mode partition noise resulting from random intra-group mode crosstalk. There is no need of complex multiple-input multiple-output (MIMO) equalization in this scheme. Furthermore, the signal-to-noise ratio (SNR) of the Received signals can be improved if a simple maximal ratio combining (MRC) technique is employed on the Receiver side to efficiently take advantage of the Diversity gain of Receiver. Intensity-modulated direct-detection (IM-DD) systems transmitting three OAM mode groups with total 100-Gb/s discrete multi-tone (DMT) signals over a 1-km GIRCF and two OAM mode groups with total 40-Gb/s DMT signals over an 18-km GIRCF are experimentally demonstrated, respectively, to confirm the feasibility of our proposed OAM-MGM scheme.
Junwei Zhang - One of the best experts on this subject based on the ideXlab platform.
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orbital angular momentum mode group multiplexed transmission over a graded index ring core fiber based on Receive Diversity and maximal ratio combining
Optics Express, 2018Co-Authors: Junwei Zhang, Guoxuan Zhu, Jie Liu, Jiangbo Zhu, Wenyong Luo, Yujie ChenAbstract:An orbital-angular-momentum (OAM) mode-group multiplexing (MGM) scheme using high-order mode groups (MGs) in a graded-index ring-core fiber (GIRCF) is proposed, in which a Receive-Diversity architecture is designed for each MG to suppress the mode partition noise resulting from random intra-group mode crosstalk. The signal-to-noise ratio (SNR) of the Received signals is further improved by a simple maximal ratio combining (MRC) technique on the Receiver side to efficiently take advantage of the Diversity gain of the Receiver. Intensity-modulated direct-detection (IM-DD) systems transmitting three OAM mode groups with total 100-Gb/s discrete multi-tone (DMT) signals over a 1-km GIRCF and two OAM mode groups with total 40-Gb/s DMT signals over an 18.4-km GIRCF are experimentally demonstrated, respectively, to confirm the feasibility of our proposed OAM-MGM scheme.
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orbital angular momentum mode group multiplexed transmission over a graded index ring core fiber based on Receive Diversity and maximal ratio combining
arXiv: Signal Processing, 2017Co-Authors: Junwei Zhang, Guoxuan Zhu, Jiangbo Zhu, Liu Jie, Wenyong LuoAbstract:An orbital-angular-momentum (OAM) mode-group multiplexing (MGM) scheme based on a graded-index ring-core fiber (GIRCF) is proposed, in which a single-input two-output (or Receive Diversity) architecture is designed for each MG channel and simple digital signal processing (DSP) is utilized to adaptively resist the mode partition noise resulting from random intra-group mode crosstalk. There is no need of complex multiple-input multiple-output (MIMO) equalization in this scheme. Furthermore, the signal-to-noise ratio (SNR) of the Received signals can be improved if a simple maximal ratio combining (MRC) technique is employed on the Receiver side to efficiently take advantage of the Diversity gain of Receiver. Intensity-modulated direct-detection (IM-DD) systems transmitting three OAM mode groups with total 100-Gb/s discrete multi-tone (DMT) signals over a 1-km GIRCF and two OAM mode groups with total 40-Gb/s DMT signals over an 18-km GIRCF are experimentally demonstrated, respectively, to confirm the feasibility of our proposed OAM-MGM scheme.
Yujie Chen - One of the best experts on this subject based on the ideXlab platform.
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orbital angular momentum mode group multiplexed transmission over a graded index ring core fiber based on Receive Diversity and maximal ratio combining
Optics Express, 2018Co-Authors: Junwei Zhang, Guoxuan Zhu, Jie Liu, Jiangbo Zhu, Wenyong Luo, Yujie ChenAbstract:An orbital-angular-momentum (OAM) mode-group multiplexing (MGM) scheme using high-order mode groups (MGs) in a graded-index ring-core fiber (GIRCF) is proposed, in which a Receive-Diversity architecture is designed for each MG to suppress the mode partition noise resulting from random intra-group mode crosstalk. The signal-to-noise ratio (SNR) of the Received signals is further improved by a simple maximal ratio combining (MRC) technique on the Receiver side to efficiently take advantage of the Diversity gain of the Receiver. Intensity-modulated direct-detection (IM-DD) systems transmitting three OAM mode groups with total 100-Gb/s discrete multi-tone (DMT) signals over a 1-km GIRCF and two OAM mode groups with total 40-Gb/s DMT signals over an 18.4-km GIRCF are experimentally demonstrated, respectively, to confirm the feasibility of our proposed OAM-MGM scheme.
Jiangbo Zhu - One of the best experts on this subject based on the ideXlab platform.
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orbital angular momentum mode group multiplexed transmission over a graded index ring core fiber based on Receive Diversity and maximal ratio combining
Optics Express, 2018Co-Authors: Junwei Zhang, Guoxuan Zhu, Jie Liu, Jiangbo Zhu, Wenyong Luo, Yujie ChenAbstract:An orbital-angular-momentum (OAM) mode-group multiplexing (MGM) scheme using high-order mode groups (MGs) in a graded-index ring-core fiber (GIRCF) is proposed, in which a Receive-Diversity architecture is designed for each MG to suppress the mode partition noise resulting from random intra-group mode crosstalk. The signal-to-noise ratio (SNR) of the Received signals is further improved by a simple maximal ratio combining (MRC) technique on the Receiver side to efficiently take advantage of the Diversity gain of the Receiver. Intensity-modulated direct-detection (IM-DD) systems transmitting three OAM mode groups with total 100-Gb/s discrete multi-tone (DMT) signals over a 1-km GIRCF and two OAM mode groups with total 40-Gb/s DMT signals over an 18.4-km GIRCF are experimentally demonstrated, respectively, to confirm the feasibility of our proposed OAM-MGM scheme.
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orbital angular momentum mode group multiplexed transmission over a graded index ring core fiber based on Receive Diversity and maximal ratio combining
arXiv: Signal Processing, 2017Co-Authors: Junwei Zhang, Guoxuan Zhu, Jiangbo Zhu, Liu Jie, Wenyong LuoAbstract:An orbital-angular-momentum (OAM) mode-group multiplexing (MGM) scheme based on a graded-index ring-core fiber (GIRCF) is proposed, in which a single-input two-output (or Receive Diversity) architecture is designed for each MG channel and simple digital signal processing (DSP) is utilized to adaptively resist the mode partition noise resulting from random intra-group mode crosstalk. There is no need of complex multiple-input multiple-output (MIMO) equalization in this scheme. Furthermore, the signal-to-noise ratio (SNR) of the Received signals can be improved if a simple maximal ratio combining (MRC) technique is employed on the Receiver side to efficiently take advantage of the Diversity gain of Receiver. Intensity-modulated direct-detection (IM-DD) systems transmitting three OAM mode groups with total 100-Gb/s discrete multi-tone (DMT) signals over a 1-km GIRCF and two OAM mode groups with total 40-Gb/s DMT signals over an 18-km GIRCF are experimentally demonstrated, respectively, to confirm the feasibility of our proposed OAM-MGM scheme.
