INITIAL ACQUISITION METHOD FOR SPREADING CODE, INITIAL ACQUISITION CIRCUIT FOR SPREADING CODE AND RECEIVER FOR SPREAD SPECTRUM COMMUNICATION

摘要

PROBLEM TO BE SOLVED: To provide an initial acquisition circuit of a spreading code for which initial acquisition time is short even when a line state is bad by selecting the expected value of reception signals most similar to written reception signals as a search code. ;SOLUTION: A pseudo random code generator 3 generates a pseudo random code which is the spreading code with the initial sequence of the pseudo random code selected by a code estimation decoder 2 as an initial value. A delay part 4 selects a sequence code by (m) stages of shift registers, the code estimation decoder 2 and the pseudo random code generator 3 and compensates delay until the pseudo random code is generated. An acquisition judgement part 7 compares the output of a square part 6 with a predetermined threshold value and judges whether or not initial acquisition is successful. Then, a search control part 8 refers to the judged result of the acquisition judgement part 7 and an estimation send-off flag outputted by the code estimation decoder 2 and loads the selected initial sequence of the pseudo random code to the pseudo random code generator 3.;COPYRIGHT: (C)1997,JPO