Identification of a nonlinear power-amplifier L-N-L structure for pre-distortion purposes

Based on power amplifier measurements a low-complex nonlinear model with memory, consisting of a memoryless, but parameterized nonlinearity, sandwiched between two linear FIR-filter is developed (L-N-L structure). Although the signal bandwidth is with 2 MHz rather small, memory effects can be noticed. Furthermore, an adaptive algorithm for continuous identification of the model parameters is developed. Simulations show that the algorithm converges in the mean-square sense to the global minimum, given only little knowledge regarding the region where this minimum lies.