| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a TDD/FH-system (time division duplexing/frequency hopping system) radio communication system whereby communication is not easily disturbed, tapping is prevented and frequency usage efficiency is improved. SOLUTION: The system is provided with hopping frequency generating means 68-80 generating a hopping frequency which is changed by a prescribed pattern at every fixed time, a frequency modulating means 66 frequency- modulating transmission data by a transmission frequency by the hopping frequency, band-pass filters 92 and 96 filtering reception data by synchronizing with the hopping frequency so as to filter reception data, a transmission/ reception selecting switch 88 connecting the band pass filter 92 to an antenna in reception, a reception frequency mixer 98 mixing reception data with a reception frequency by the hopping frequency, an intermediate frequency mixer 102 mixing the output with an intermediate frequency and a frequency demodulating means 106 demodulating the output.</p> |
