| 摘要 |
<p>An apparatus for, and a method of, generating a predistorted radio frequency signal, which has a spectrum mask that avoids undesirable spurious emissions. The magnitude uk of each complex baseband sample pair is determined and a distortion factor Dk, based on a scaled value of the inverse hyperbolic tangent of the magnitude, divided by that magnitude, is determined. Each sample of the in-phase component Ik and of the quadrature component Qk is multiplied by the corresponding distortion factor Dk. In one embodiment, the scaling factor is a constant value approximating the transfer function of the power amplifier. In another embodiment the scaling factor is determined in a feedback circuit, based on the power amplifier output. <IMAGE></p> |
