| 摘要 |
<p>Signal processing to remove unwanted signal components of non-linear elements such as RF amplifiers in broadband wireless communications systems that exhibit unwanted intermodulation products. An information signal is processed to form a processed output signal, Vod. A signal preprocessor includes a base modulator for modulating the information signal to form base modulated signals, a band modulator for modulating the base modulated signals to form an input signal, Vi, a distortion processor for providing a predistortion signal Vpd having selected predistortion terms of the Taylor series form [k1(Vi)1, k2(Vi)2, k3(Vi)3,...], and a broadband processor for combining the input signal V¿i? and the predistortion signal Vpd to form a predistorted signal Vid with the selected predistortion terms of the Taylor series form [k1(Vi)?1, k¿2(Vi)2, k3(Vi)3,...] having reduced amplitude. A non-linear element having a non-linear transfer function for process the predistorted signal V¿id? to form the output signal with the selected predistortion terms of the Taylor series form [k1(Vi)?1, k¿2(Vi)2, k3(Vi)3,...] having reduced amplitude. Amplifiers achieve substantial improvements in efficiency, an increase of 40-80% of usable power, due to the reduction of intermodulation products. In particular, the third order products are reduced.</p> |
