Arrangement for reducing interference, caused by sunlight modulation, on a received signal which forms part of a system for optical information transmission

摘要

In an arrangement for transmitting an optical pulse sequence 15, use is made of a laser diode 2 and a control circuit 3 connected thereto. Instead of using homogeneous pulses in the optical pulse sequence 15, a pulse train with two or more part pulses is used for each pulse. These part pulses are brought about by a laser diode 2 being activated and deactivated a number of times during the pulse time t of the homogeneous pulse. The receiver for the transmitted pulse sequence 15 includes a detector 4 and a signal-processing circuit 5. The signal- processing circuit comprises a band-pass filter 18 which allows passage of that part of the frequency spectrum of the optical pulse sequence 16 which has significant amplitudes and has been shifted by virtue of the fact that each pulse in the pulse sequence itself consists of two or more part pulses instead of one homogeneous pulse.