| 摘要 |
PURPOSE:To suppress the deterioration in a power ratio D/O of a power of a desired wave to a power of an undesired wave by multiplying a specific complex series from a complex spread series generating means with transmission data so as to implement spread modulation. CONSTITUTION:A complex spread series generating means 2 outputs a complex spread series PN(K)=M(K).Z(K) obtained by multiplying a complex series Z(K) expressed in equation I with a spread series M(K). Then the series PN is multiplied with transmission data D(K) by a spread modulation means 1, which implements spread modulation and the data are sent through an orthogonal modulation means 3 and a power amplifier means 4 or the like to which a carrier is applied. The data are similarly subject to inverse spread processing at a receiver side and demodulation is implemented. According to the system, a signal point of a modulation wave does not pass through a zero, the phase changes by 90 deg. but not changed by 180 deg., envelope fluctuation of the modulation wave is suppressed, and out-band radiation is small even when nonlinear amplifier is employed for the means 4 and the D/O deterioration is suppressed. |
