| 摘要 |
PURPOSE:To accurately decide signal reception completion even when a reception signal level is low by deciding signal completion by changing a signal completion reference level at every decision of signal completion, and detecting the reception completion of a spread spectrum signal when a correlation value goes less than a reference level for prescribed number of times continuously. CONSTITUTION:After the synchronism of a signal correlation detection circuit 8 is established, the decision circuit 12a of a signal completion detection circuit 12 initializes a completion reference level B a little lower than the correlation peak value of correlation value data (a) inputted first from the circuit 8. The circuit 12a compares the correlation value data (a) gated at every period with the reference level B, and counts down the signal count of a counter by one when the data (a) shows a level less than the level B. The reference level is set again at a level a little lover than the maximum value (p) of the data (a) when the count shows a value other than zero. When the completion count arrives at zero by repeating such operation, the circuit 12a judges it as the signal reception completion, and outputs the completion signal (c) to the signal correlation detection circuit 8. |
