公开(公告)号：US5058134A

公开(公告)日：1991-10-15

申请号：US397949

申请日：1989-08-24

申请人： Pierre R. Chevillat ,  Evangelos Eleftheriou ,  Dietrich G. U. Maidwald ,  Michel Quintin

发明人： Pierre R. Chevillat ,  Evangelos Eleftheriou ,  Dietrich G. U. Maidwald ,  Michel Quintin

IPC分类号： H04L7/10 ,  H04J3/06 ,  H04L27/18 ,  H04L27/22 ,  H04L27/34 ,  H04M11/00

CPC分类号： H04L27/3455 ,  H04J3/0605

摘要： In data transmission wherein a transmitting modem transmits data signals to a receiving modem via a telephone line, the process of rotating, in the transmitting modem, the phase of the point of the constellation resulting from a group of data bits by a predetermined phase value, and then rotating, after a predetermined delay in the receiving modem, the phase of the estimated point resulting from the transformation of the analog signal by the opposite of said predetermined phase value, and calculating the mean-squared error between the rotated point and the estimated point of the constellation the error being used to determine whether the receiving modem is out of synchronization.