FIELD: radio engineering, communication.
SUBSTANCE: versions of tone modulations of pilot signal to optical signals by inserting offset bits into data frames carried by optical signals are described. Since modulation is performed by modifying data, the depth of modulation is accurate, and there is no need for calibration or control of feedback. In one version, a transmitter determines a tone modulation period of the pilot signal for tracking or identifying an optical channel. The transmitter inserts a sequence of offset bits, periodically in accordance with a certain period, into a plurality of frames containing the original data bits. The amplitudes of the optical signals carrying the frames are modulated at a higher frequency than the tone modulation of the pilot signal. The optical signals are then transmitted, including the offset bits in the frames.
EFFECT: improving the quality of communication.
21 cl, 8 dwg
