| 摘要 |
PROBLEM TO BE SOLVED: To provide a carrier detection method for omitting unnecessary operations of a demodulation processing circuit by discriminating whether or not a signal is a signal of its own system until detection of a symbol timing is finished. SOLUTION: This receiver adopting the carrier detection method includes a correlation detection circuit 104 for detecting a known fixed pattern of a preamble signal in addition to an RSSI measurement circuit 102 and activates them simultaneously. A received signal is given also to the correlation detection circuit as soon as the received signal is given to the RSSI measurement circuit, and when a carrier correlation detection threshold value comparison circuit 105 discriminates that the correlation value of the correlation detection circuit exceeds a preset threshold value, it is regarded that the carrier correlation is detected. Demodulation is started tentatively on the opportunity when an OR circuit 106 detects either of the carrier correlation detection and carrier detection by the RSSI measurement circuit, and even when the demodulation is started by the carrier detection by the RSSI measurement circuit, if the correlation detection circuit discriminates no detection of the correlation, the demodulation is stopped. COPYRIGHT: (C)2006,JPO&NCIPI |
