| 摘要 |
PROBLEM TO BE SOLVED: To prevent the deterioration of transmission efficiency under a multipath environment. SOLUTION: A packet 30 having a preamble part 31 and a data area part 32 is SS-modulated and transmitted from a transmitter 10. When a signal is not received, a receiver 20 alternately switches first and second receiving antennas 21 and 22 in a prescribed cycle by an antenna switch circuit 23, converts the received signal into an intermediate frequency signal by an RF circuit 24, and supplies it to inverse spread demodulating circuit 25. Correlation between the received signal and a spread code system generated by a spread code generator 26 is calculated by the inverse spread demodulating circuit 25, and the output is impressed to a packet receiving circuit 28 and an antenna switching control circuit 27. When the preamble part 31 of the packet 30 from the prescribed transmitter is received, and the prescribed number of correlation peaks are outputted in the output of the inverse spread demodulating circuit 26, the antenna switching control circuit 27 controls the antenna switching circuit 23 not to operate the switching of the receiving antennas 21 and 22. |
