A Digital Subband Filtering Predistorter for TETRA System

This paper proposes a digital adaptive predistorter based on subband filtering for TETRA digital trunked system. Digital subband filtering predistorter divides transmitting signal into several subbands to linearization, the requirement of processing speed is reduction, convergency of adaptive process is enhanced. The subband filtering technology solves the problem of power amplifier’s memory characteristic introduced by expansion of signal band, it can be used to improve the work band of digital predistorter. Simulation result of TETRA multicarrier signal exhibits excellent performance of the proposed predistorter for memoryless power amplifiers and memory power amplifiers, extend the power amplifier linearity range efficiently.