2019 Fiscal Year Research-status Report
Novel fronthaul technology for massive and ultra-dense radio access networks
| Project/Area Number |
18K04156
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| Research Institution | National Institute of Information and Communications Technology |
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Principal Investigator |
PHAM TIENDAT 国立研究開発法人情報通信研究機構, ネットワークシステム研究所ネットワーク基盤研究室, 研究員 (50636321)
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| Co-Investigator(Kenkyū-buntansha) |
梅沢 俊匡 国立研究開発法人情報通信研究機構, ネットワークシステム研究所ネットワーク基盤研究室, 主任研究員 (20636047)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | radio over fiber / mobile fronthaul / fiber radio / optical communications |
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| Outline of Annual Research Achievements |
We designed and fabricated a 80-GHz high-power integrated photoreceiver. The integrated photoreceiver consisted of a zero-bias operational broadband uni-traveling carrier photodetector and a high-power linear amplifier. An integrated 20-GHz photoreceiver was designed and fabricated using a PIN-type photodetector chip and a 20-GHz high-gain amplifier. We transmitted more than 80-Gb/s and 40-Gb/s 2x2 multiple-input multiple-output fiber-wireless system in the 90-GHz band using wavelength-division multiplexing intermediate-frequency-over-fiber technology in the downlink and uplink, respectively. We also demonstrated a high-speed integrated fiber-wireless system and satisfactory performance is experimentally confirmed for transmission of 4×25-Gb/s signal in the 90-GHz band.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
We successfully developed key devices for the project, including an integrated 80-GHz broadband uni-traveling carrier photodetector module that will be integrated into a receiver module for carrier signal and power generation, and an integrated linear low-speed photoreceiver for detection of intermediate frequency data signals. We also successfully developed important digital signal processing techniques, including filter band multicarrier modulation and multiband filter band multicarrier modulation for single-input single-output and multiple-input multiple-output systems. We also developed a high spectral efficiency Nyquist-shaping subcarrier modulation technique with a pre-equalization method for high-performance signal transmission. Demonstrations of high-speed and multiple-channel transmission of signals over the system, both in downlink and uplink directions, were successfully implemented. The achieved results have been presented in domestic and international conferences.
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| Strategy for Future Research Activity |
We will improve the developed algorithms for aggregating a large number of intermediate frequency signals, mapping the signals to several wavelength-division multiplexing systems, and transmitting them over different parallel optical channels. We will use the developed devices and digital signal processing for the system demonstration in the final year of the project. Proof-of-concept experiments for high-speed mobile fronthaul system for massive and ultra-dense radio access networks, including experiments for large-scale multiple-input multiple-output signal transmission and experiments for a large number of parallel channel system, will be implemented.
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| Causes of Carryover |
We have a small amount remained from this fiscal year and will be combined with the budget of the next fiscal year to buy some devices and components.
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