| 摘要 |
PROBLEM TO BE SOLVED: To improve transmission efficiency by simultaneously sending a frequency hop modulation signal and a spread spectrum modulation signal without interference and sending a synchronizing timing signal of the hop modulation signal with the spread modulation signal. SOLUTION: A narrow band signal whose band width BW1 has a relation of BW1 <fT/N is product-modulated by using a maximum period series code whose spread code length is N-bit generated based on a clock signal whose frequency is fT and the direct system spread spectrum modulation signal subjected to spread spectrum processing is sent. Moreover, A frequency hop modulation signal is simultaneously sent to hop a center frequency of a narrow band signal whose band width BW2 has a relation of BW2 <fT/N-BW1 to a frequency position of f1±(1+2m)fT/2N, where the f1 is the center frequency of the spread spectrum modulation signal. The hop modulation signal is hopped in a timing based on a correlation synchronizing timing of the spread spectrum modulation signal. |
