Transmission system for transmitting signals in a burst mode

Abstract

The receiver processing circuitry performs the steps of an iterative process and in each step derives from a received signal Iin a threshold value related to a characteristic of the signal. This value is stored via an analog-to-digital convertor AD in a memory MEM. The characteristic of the signal Iin is then compared in a comparator consisting of two comparator circuits C1 and C2 and a switch S, with a threshold value stored previously for the substation which sent Iin. This value is prior to receipt of Iin, i.e. during a previous timeslot, applied to, e.g., C1 via a digital-to-analog convertor DA1. During this comparison a threshold stored for the substation which is next to transmit a signal is retrieved from MEM via a digital-to-analog convertor DA2. The result of the comparison is via S generated at Dout and represents the digital conversion of Iin. The power of the transmitted signals is controlled by a circuit included in the transmitters of the system. This circuit compares the peak power values of a maintenance signal coupled back via a backfacet diode D with reference values REF1 and REF 2 and controls a laser circuit L based on the result of the comparison stored in a memory MEM2.