| 摘要 |
PURPOSE:To attain the transmission of narrow band with high power efficiency even when an amplifier with a nonlinear distortion is used by distorting an input signal of the amplifier with the nonlinear distortion in advance so as to obtain an output signal without distortion. CONSTITUTION:A base band signal generator 2 generates a base band signal xj and a power signal generator 3 generates powered values xj, xj<1>,...xj<n> and loads them in a shift register 4. Then the powered values and coefficients c1(<j>)-cn(<j>) stored in a shift register 6 are read out and a product sum computing element 6 outputs a signal yj added with distortion. The output signal yj is amplified by an amplifier 9 via a D/A converter 7 and an amplitude phase modulator 8. since the inverted characteristic of the distortion added by the amplifier 9 is generated by n-order polynomial whose coefficients are c1(<j>)-cn(<j>), the output signal of the amplifier 9 has an entirely linear characteristic. Thus, the narrow band transmission is attained by using the amplifier with high power efficiency and nonlinear distortion. |
