Receiver for multi-level digital signals.

摘要

In a digital transmission system comprising a transmitter (2) coupled via a channel (4) to a receiver (6) a detection signal rk is compared with a number of reference values to determine the destination symbols a/< ANd >k. Since the size of the received signal rk is not known in advance, the ratio between the detection signal and the reference values is to be determined by adapting means (16) on the basis of the received signal and the decisions made. The problem may then occur that as a result of an initially erroneous value of the ratio between detection signal and reference values not a correct adaptation is made. By recognizing according to the inventive idea such a situation because specific values of the symbols a/< ANd >k are lacking, in such a situation said ratio can be brought to such a value by the correction means (18) that all the values of a/< ANd >k again occur.