Adaptive Linearization Scheme for Power Amplifiers in OFDM Communication Systems
An adaptive linearization scheme based on the Exact Model-Matching (EMM) approach is proposed to compensate nonlinearity of high power amplifiers (HPAs). It is illustrated that the input-output property of the broadband amplifier system can be approximated by a Memory Polynomial Model (MPM). Then, the compensation of HPA input is determined from the MPM in a real-time manner, and consequently, the linearization from the nonlinearity compensator (predistorter) input to the HPA output can be attained even though the nonlinear dynamics of HPA has uncertainty and is time-varying. The effectiveness of the proposed adaptive linearization scheme is validated in numerical simulation in a 64QAM-OFDM communication system.