| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of frame step-out even in the transmission line of strong fluctuation like a moving transmission line for which large delay waves are present by constituting a frame phase detector by the M pieces of the delay circuits of different delay amounts, the M pieces of matched filters and a convex function judgement circuit for judging the output of the matched filters and detecting an accurate peak position at all times. SOLUTION: Reception signals considered as a unique word pattern are branched, respectively L symbol delayed in delay devices 6-8 and then, inputted to the matched filters 9-12. The convex function judgement circuit 13 performs correlation computation with a unique word by the M pieces of different initial phases from the output of the matched filters 9-12, identifies whether or not it is turned to a convex function relating to a desired phase and performs output to a frame counter as synchronizing signals. Thus, in the transmission line of a large delay spread, a frame phase is detected by an optimum phase at all times and phase fluctuation is followed up even in the case that the delay spread fluctuates. |
