COMPENSATION OF NONLINEAR DISTORTION DURING TRANSMISSION BASED ON THEADAPTIVE PREDISTORTION METHOD

In many efforts to increase the efficiency af power amplifiers of mobi le terminals, compensation of nonlinear distortion based on an adaptiv e predistortion method has performed an important role. In the course of basic evaluation of a method using a look-up table (LUT) and a meth od using an approximation for compensation of nonlinear distortion, a newly developed method using approximation and a ROM type LUT with a s mall-sized memory has been proposed to overcome barriers to practical application and disadvantages associated with the LUT method. Experime ntal trials of the proposed method were applied to narrow-band digital modulation systems. As a result, the proposed method was round to pro vide a satisfactory capability of compensating nonlinear distortion, w ith nest adjacent channel interference of less than -55 dBc. The propo sed method has advantages such as a small memory size and excellent RF performance, and is expected to occupy an important position in many adaptive predistortion methods.