Joint Channel Estimation and Nonlinear Distortion Compensation in OFDM Receivers

Abstract: Nonlinear distortion in power amplifiers (PA) can significantly degrade performance of orthogonal frequency division multiplexed (OFDM) communication systems. This paper presents a joint maximum-likelihood channel frequency response and nonlinear PA model estimator for OFDM signals. Derivation of the estimator is based on Taylor-series representation of power amplifier nonlinearity and is suitable for wide range of memoryless PA models. A sub-optimal decision-aided algorithm for adaptive compensation of nonlinear distortion effects at the receiver-side is also presented. It is shown that the proposed algorithms can be used in IEEE 802.11a/g/p/ac compliant wireless LAN receivers without any modifications at the transmitter side. The performance of the proposed algorithms is studied by means of computer simulation.