Proposal and demonstration of OFDM terrestrial digital signal multi-channel batch conversion method for emergency CATV broadcasting such as tsunami flood

2021 Fiscal Year Final Research Report

• Project/Area Number: 17K06421
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Communication/Network engineering
• Research Institution: University of Toyama
• Principal Investigator: KIKUSHIMA Koji 富山大学, 学術研究部工学系, 教授 (50516242)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: 多チャネル一括変換 / ＯＦＤＭ地デジ信号 / 緊急放送 / ＣＡＴＶ / 光ファイバ伝送システム / アクセス系 / 変調方式 / 光変調

Outline of Final Research Achievements

The modulation characteristics of the OFDM terrestrial digital signal multi-channel batch conversion system for emergency CATV broadcasting such as tsunami floods were clarified. For the first time in the world, we have shown the experimental results of 3-channel simultaneous OFDM television signal modulation using an external light modulator. In the experiment, carrier suppression was performed to improve the modulation characteristics. Furthermore, we clarified the modulation characteristics such as the effect of the change in the modulation index of the optical modulator on the signal quality.
Specifically, two external optical modulators were used to simultaneously modulate a 3-channel TV signal using a multi-channel simultaneous OFDM modulation scheme. As far as we know, this is the first successful experiment in the world.

Free Research Field

アクセス系光ファイバCATV伝送システム

Academic Significance and Societal Importance of the Research Achievements

多チャネルを一括して同一の緊急放送番組により地デジＯＦＤＭ変調できる新しい方式なので，ＣＡＴＶ局が市区町村のきめ細かな緊急情報を迅速に映像でわかりやすく放送できるようになり，緊急時に役に立つ市区町村の単位での，きめ細かなリアルタイム情報を，遠隔から映像編集装置を操作して，画面分割数の変更を可能とし，ＣＡＴＶ放送できるようになる。
また，中央官庁，県庁，市町村役場からの，さまざまな緊急情報を遠隔地からＣＡＴＶ放送できるので，テレビ局，ＣＡＴＶ局の従業員も避難できる。