| 摘要 |
PROBLEM TO BE SOLVED: To obtain the equipment and the system that has a means demodulating a transmission signal without being affected by interference at a receiver side in the case that the receiver side receives a transmission signal being a code spread signal and especially a delaymultiplex signal with an inter-symbol interference asynchronously with the transmitter side. SOLUTION: A received signal is converted into a base band frequency signal by a guadrature demodulator 33 through a frequency conversion circuit 32. I, Q signals after demodulation are converted by A/D converters 34, 35 by using a clock whose frequency is a multiple (n) of a chip rate. The A/D conversion data are converted into two (=n) series of I1, I2 and Q1, Q2 at S/P converters 36, 37 and the data are given to correlation devices 13,14. The correlation outputs are latched by a correlation synchronization circuit signal and given to power measurement circuits 47, 48, from which correlation power signals P1, P2 are outputted. They are compared by a power comparator 49, a selection signal is fed to signal selection circuits 50, 51 as the result and a set of the correlation output data with large power is selected. A demodulation section 52 demodulates the data by using the data of the selected signal series. |
