BURST SIGNAL DETECTING CIRCUIT

摘要

PURPOSE:To detect the arrival of a burst signal with a different amplitude for each ONU(optical network unit) provided with a DC component in the burst multiplex transmission system of a PDS(passive double star) system in a short time. CONSTITUTION:An NRZ burst signal (a) outputted from an optical receiver 1 is turned to a signal (b) by performing DC cut-off at a capacitor 2. By providing a phase circuit 3 to apply phase transition to the signal (b) and calculating difference between the signal (b) and a phaser output signal (c) by using a differential amplifier 4, a bipolar signal (d) canceled the DC component is provided. A counter circuit 8 is operated by the bipolar signal (a) and after the prescribed number of pulses are counted, a burst detect signal (k) is outputted.