| 摘要 |
<p>PURPOSE:To obtain a spread system transmitter-receiver in which a PN code is selected without need of a complicated circuit by using a surface acoustic wave SAW matched filter for correlation demodulation. CONSTITUTION:An information signal received from an information input section 7 to a transmission section 1 is subjected to information modulation at an information modulation section 3 and the result is inputted to a spread modulation section 4. On the other hand, a PN generating section 5 uses a selection section 6 to select one of spread codes (PN codes) and an information modulation signal received by the modulation section 4 uses a PN code generated in the PN generating section 5 to be subjected to spread modulation to the signal of a broad band and the resulting signal is sent to an antenna 8. The transmission signal is received by an antenna 12 and inputted to a receiver 2 and a selection section 9 selects a terminal of a correlation demodulation section using a SAW matched filter to set a PN code. When the PN code of the reception signal is coincident with the set PN code, a demodulation signal is outputted and an information demodulation section 11 demodulates the signal into an original information signal, and the demodulated signal is outputted from an output section 13. As a result, correlation demodulation corresponding to plural PN codes is realized with simple configuration.</p> |
