| 摘要 |
PROBLEM TO BE SOLVED: To shorten the time from the start of a search to the acquisition of an identification code superposed on a satellite signal. SOLUTION: A chip position offset counter 16 generates an offset value which is increased by one chip width in each cycle corresponding to an integral multiple of PN code length and an offset code generator 18 generates an offset code for making a phase shift alternately in the front-rear direction of an initial chip position in every cycle corresponding to the PN code length. After a multiplier 17 multiplies those offset value and offset code by each other, the result is added to the code position signal obtained by a chip position counter 12. A PN code generator 19 generates a PN code oscillation signal showing reverse characteristics thereafter according to the code position signal obtained by the adder 13 and a multiplier 20 multiplies the PN code oscillation signal by a receive signal to acquire a phase-shifted identification code. |
