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In telecommunication, coded mark inversion (CMI) is a non-return-to-zero (NRZ) line code. It encodes ''zero'' bits as a half bit time of zero followed by a half bit time of one, and while ''one'' bits are encoded as a full bit time of a constant level. The level used for ''one'' bits alternates each time one is coded. This is vaguely reminiscent of, but quite different from, Miller encoding, which also uses half-bit and full-bit pulses, but additionally uses the half-one/half-zero combination and arranges them so that the signal always spends at least a full bit time at a particular level before transitioning again. CMI doubles the bitstream ''frequency'', when compared to its simple NRZ equivalent, but allows easy and reliable clock recovery. == References == * ITU-T G.703 (11/2001), Annex A, A.3 Definition of CMI. * ((google patents link )) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Coded mark inversion」の詳細全文を読む スポンサード リンク
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