In this paper we present a technique to achieve accurate PA linearization using a cascade of two DPD blocks. First, a coarse inverse is generated by using a broadband identification method. As this coarse inverse has fixed coefficients for every signal, it does not require any signal dependent training. The residual nonlinearity of the cascade of the coarse DPD and PA is then compensated by a small adaptive fine tuning DPD block. This cascaded linearization methodology achieves high linearity with a small number of adaptive coefficients.
Index Terms — Broadband transmitters, digital predistortion, power amplifiers.