An Efficient QAM Detector via Nonlinear Post-Distortion Based on FDE Bank Under PA Impairments


SALMAN M. B. , GÜVENSEN G. M.

IEEE TRANSACTIONS ON COMMUNICATIONS, vol.69, no.10, pp.7108-7120, 2021 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 69 Issue: 10
  • Publication Date: 2021
  • Doi Number: 10.1109/tcomm.2021.3095974
  • Journal Name: IEEE TRANSACTIONS ON COMMUNICATIONS
  • Journal Indexes: Science Citation Index Expanded, Scopus, Academic Search Premier, PASCAL, Aerospace Database, Applied Science & Technology Source, Business Source Elite, Business Source Premier, Communication & Mass Media Index, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex, zbMATH, Civil Engineering Abstracts
  • Page Numbers: pp.7108-7120
  • Keywords: Nonlinear distortion, Receivers, Wireless communication, Analytical models, Quadrature amplitude modulation, Peak to average power ratio, Measurement, Nonlinear power amplifiers, nonlinear post-distortion, nonlinear ISI, FDE for nonlinear channels, FREQUENCY-DOMAIN EQUALIZATION, DIGITAL PREDISTORTION, GAUSSIAN-PROCESSES, CARRIER, SYSTEMS, CHANNELS, MIMO, MODULATION, MEMORY

Abstract

In this paper, we propose a receiver structure for single-carrier uplink transmission with frequency domain equalization (FDE) that is exposed to power amplifier (PA) nonlinearities. A two-stage approach is adopted, in which linear communication channel is equalized at the first stage, and it is followed by post-distortion, where nonlinear distortion is reduced. In the literature, nonlinear processing techniques are proposed, which perform memoryless compensation of nonlinear distortion together with FDE. However, in this study, we show that even if memoryless nonlinearity exists, the received signal is impaired by nonlinear inter-symbol-interference. Therefore, we propose a class of symbol rate post-distortion techniques, which use neighboring received symbols to suppress the nonlinear interference. Three different post-distortion methods, Gaussian process regression (GPR), neural network (NN) and Volterra series (VS) based post-distorters, are considered. Also, a combiner, which intelligently combines the outputs of fractional delayed bank of FDE's after post-distortion, is proposed to overcome performance degradation of FDE for frequency selective channels under nonlinear distortion. Performances of the proposed techniques are compared with state-of-the-art approaches in terms of bit error rate (BER) and achievable information rate (AIR) metrics. Simulation results demonstrate that post-distortion methods together with bank of FDE outperform state-of-the-art techniques.