PURPOSE: To attain initial synchronization of a correlation device stable at all times by comparing an output of the correlation device correlating a received PN code and a reference PN code with a prescribed decision pattern and using a coincident output so as to control the phase of the reference PN code.
CONSTITUTION: The received PN code and the reference PN code are given to the correlation device 1 and a correlation pulse is outputted from a binarizing circuit 2. The correlation pulse is inputted to a matching filter 3 and when the pattern of the correlation pulse is coincident with a prescribed pattern, a pulse is outputted to an up-down counter 4. A PN code phase control pulse generation circuit 8 is triggered by the pulse from the counter 4 and the phase control pulse of the reference PN code is outputted to a reference PN code generator 5, a sampling pulse and window pulse generator 6 and a digital phase locked loop circuit. Through the operation above, the phase of the received PN code and that of the reference PN code are made coincident.
MORI SEIJI
HAMATSU MASAHIRO
| JPS61296834A | 1986-12-27 |