Adaptive predistortion for RF power amplifier based on new look-up table indexing method

In this paper a digital Look-Up Table (LUT) predistortion structure for linearization RF Power Amplifier (PA) is presented based on a new LUT indexing technique. Unlike other LUT predistorter using simple function to implement LUT indexing, in this structure an added indexing LUT is used and so the optimum table spacing could be realized. This new LUT indexing method is detail discussed in the paper and the basic implement way of this indexing LUT is presented. A simple gradient adaptation algorithm is used in the researched system with polar structure LUT. The simulation result shows this scheme attains better performance in comparison with other wellknown indexing method but no increasing the hardware implementation complexity.