| 摘要 |
PROBLEM TO BE SOLVED: To provide a direct spreading complement sequence repetitive modulation type comb-teeth spectral communication system employing a self- complementary sequence that can prevent appearance of a side lobe in an autocorrelation characteristic, makes a correlation value in the autocorrelation characteristic zero, limit a band of a transmission signal, and minimize deterioration in the SNR due to a noise intruded in a transmission channel. SOLUTION: A transmitter 4 is provided with two multipliers 21, 22 that multiply different spread codes with transmission data to generate a comb-teeth spread spectral signal, two route Nyquist filters 14, 24 that respectively limit a frequency band of the comb-teeth spread spectrum signal generated by the multipliers 12, 22, two multipliers 18, 28 that multiply carriers having different frequencies with output signals from the two route Nyquist filters 14, 24 and an adder 30 that sums output signals from the multipliers 18, 28 to generate a transmission signal. |
