著者

根津 俊一 石川 賢二 木村 知弘 村上 弘規 橋間 明生

出版者

一般社団法人映像情報メディア学会

雑誌

テレビジョン学会技術報告 (ISSN:03864227)

巻号頁・発行日

vol.15, no.14, pp.1-6, 1991-02-21

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Television transmission services, such as business TV, via communication satellites started in 1989. For these services, we have developped a scrambling system based on the system standerdized for broadcasting satellite. This new system is characterized by positive sync. and modified line permutation resulting in high security and high quality of descrambled signal for video and by range-bit conversion resulting in softer scrambling noise for audio.

著者

林 健一郎 木村 知弘 影山 定司 原田 泰男 木曽田 晃 坂下 誠司

出版者

一般社団法人映像情報メディア学会

雑誌

テレビジョン学会技術報告 (ISSN:03864227)

巻号頁・発行日

vol.20, no.53, pp.55-60, 1996-10-17

被引用文献数

42

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This paper proposes an adaptive equalization technique for OFDM (Orthogonal Frequency Division Multiplexing) demodulation. This technique estimates a channel response with using pilot signals embedded in OFDM symbols. A two dimensional filter used for interpolating the response estimates the channel response accurately, and also improves the C/N by reducing noise bandwidth. The bit error rate performance of the system in various channels is calculated by computer simulation, and the relative C/N improvement to differential demodulation is about 2.5 dB. And the result shows that the optimum filter can be determined by the maximum path delay time and the maximum doppler frequency of the channel.