Non-iterative adaptive baseband predistorter for RF power amplifier linearisation

A digital baseband predistorter based on a non-iterative adaptation method is presented. In the proposed solution, the adaptation process is simple and fast without convergence restrictions. The predistortion gain table is directly extracted in rectangular form overcoming the requirement for the sequential extraction of the AM/AM and AM/PM gain tables. In addition, any polar to rectangular gain transformation is eliminated. The performance of the method under different imperfections is examined. Experimental results obtained on an in-house system prototype show a linearity improvement in excess of 25 dB.