Linearization of Time-varying High-power Amplifier using Adaptive Digital Predistorter
نویسنده
چکیده
An efficient adaptive predistortion technique is proposed to compensate linear or nonlinear distortions caused by a high-power amplifier (HPA) with memory in OFDM communication systems. Previous adaptive predistortion techniques, based on Volterra series, are not suitable for real-time implementation due to high computational burden and slow convergence rate. In the proposed approach, the memoryless HPA preceded by a linear filter is modeled as a Wiener system, which is then precompensated by the proposed adaptive predistorter. The adaptive algorithm is derived using the stochastic gradient method and simple proof of the stability for the Wiener system is presented. The performance of the proposed predistortion algorithm is demonstrated by computer simulations. The performance of a communication system suffering from linear and nonlinear distortion can be greatly improved
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