| To support high data rates, modern digital communication systems utilize linear modulation schemes which achieve high bandwidth efficiency. Because these modulation schemes exhibit large peak-to-average power ratios (PAPRs), the performance of the communication transceivers is very sensitive and susceptible to nonlinear distortions, which arise mainly from the high power amplifier (HPA). This is especially true in wireless systems, where in order to achieve good power efficiency, the amplifiers operate near the saturation point. In addition, the wideband characteristics of the transmitted signals cause the nonlinear distortions to be frequency-dependent, which further degrades the overall system performance.; This thesis proposes an algebraic solution to compensate at the transmitter for nonlinearity of the HPA with memory effects, where the HPA behaviorial model is represented by the Hammerstein structure, a cascade of a memoryless nonlinear block followed by a linear filter. In particular, a frequency domain parameter identification methodology is developed that first estimates the parameters of the unknown nonlinearity, which are modelled through a polynomial expansion. (Abstract shortened by UMI.)... |
