Digital Pre-Distorter System Based on Memoryless Hammerstein Model for High Power Amplifier Impairments

Due to the limitation of high power amplifier's (HPA) physical structure, challenges such as nonlinearity and memory distortions which impact the transmitted signal in HPA system remain as an open research problem. As such, this paper introduces a simple and low complex Hammerstein model design as a digital predistorter (DPD) which can handle both of the mentioned challenges. This model first estimates the reverse error to deal with the nonlinearity effect. Subsequently, the DPD complexity is eliminated by removing the order of the memory polynomial. In order to reduce the memory effect resulting from HPA, the proposed model deploys traditional filter such as Finite Impulse Response to the acquired signal in the Hammerstein model. The simulation results show that the proposed DPD outperforms the current best practices for nonlinearity by 96% from the ideal signal, and memory effect compensation by 95% from the original signal position in space. Based on that, the proposed DPD can be utilized as conventional HPA for transmitting a standard signal with minimum risk of distortion, and achieving high signal to noise ratio against state-of-the-art models.