Amplifier's predistortion-based linearizers for forward-channel link broadband applications

In this paper, an adaptive baseband/RF predistorter tracking the emerging technologies evolution of digital receivers is presented. The linearizer performs the extraction of the nonlinear time-variant behaviour of the PA to correlate the predistortion transfer functions and develop an adaptation algorithm performing a distortion level computation in time domain. CDMA standard signals applying different stress level on PA are used to evaluate the performance of the predistorter. The entire system is validated using DSP/RF co-simulation for a typical 44-dBm-class AB power amplifier. Results from different cases of standards signals reveal a significant reduction in effective output power back off (OBO).