The pseudo pulling included evasion mode null in the standard

摘要

PURPOSE:To evade 4PSK pseudo pull-in operation by observing the digital arithmetic output of a loop and detecting the pseudo pull-in operation. CONSTITUTION:The track of a detected value based upon the transition of input data is as shown by A during normal pseudo pull-in operation, but as shown by B and C during pseudo pull-in operation. The difference in track between the normal pull-in operation and pseudo pull-in operation depending upon whether a swivel component is present or not is observed by the output 110 of a digital computing element 129. In this case, levels L and H are observed with the half- and-half probability in the normal pull-in operation, but only the level L or H is observed in the pseudo pull-in operation. For this purpose, this is observed by a counting circuit 134 to detect the pseudo pull-in operation.