公开(公告)号：JP2001086181A

公开(公告)日：2001-03-30

申请号：JP2000224391

申请日：2000-07-25

Applicant: LUCENT TECHNOLOGIES INC

Inventor： GORDON ALEXANDER ,  TSAI SHENG-JEN ,  MATUSEVICH ALEX ,  TOBIAS JONATHAN M ,  WANG ROBERT C

IPC: H04L27/22 ,  G01S1/04 ,  G01S5/10 ,  H04B7/26 ,  H04J3/00 ,  H04L27/14 ,  H04Q7/34

Abstract: PROBLEM TO BE SOLVED: To create and measure an event provided with a continuing time for only several nano-seconds by stipulating a symbol transition time between symbols by a frequency measurement value. SOLUTION: The second copy of a quadrature phase shift keyed(QPSK) signal passes through a frequency modulator (FM demodulator) 120 to create the measurement value of an instantaneous frequency of the signal. A peak detector 124 catches a peak in a frequency output and creates a signature. A digital signal processor 126 gives a proper signature signal (signature event) to a call processor 128, demodulates a time slot symbol in a T/2 symbol period and obtains phase transition between the two prescribed symbols. The processor 126 monitors a T/2 window and catches the occurrence of the peak. The call processor 128 receives the signature event and seals a time stamp on it. The demodulated inter-symbol transition time is stipulated based on the frequency measurement value.