Non Linear Distortions introduced by Amplifiers on COFDM signals. Measurements, Effects and Compensation Techniques

  • S Andreoli
  • P Banelli
  • A Longaroni
  • C Massini


Coded Orthogonal Frequency Division Multiplexed (COFDM) techniques, used by terrestrial European broadcasting systems (DAB, DVB-T), could be adopted in the last mile of the downlink channel for Wireless Broadband Communication System to provide Multimedia Services to mobile or nomadic users by cellular coverage techniques, as evinced from the actual research activity. COFDM signals are characterised by non-constant envelope (peak-to-mean power ratio > 10 dB) which forces to project amplifiers with low or well-counteracted non-linear distortion effects. Our aim is to present Itelco experience to characterise non-linear distortions introduced by final amplifiers on COFDM signals (AM/AM, AM/PM and NonLinearities with Memory). Both experimental measurements and simulation results will be shown. Moreover we will point out the improvements achievable by digital baseband predistortion, to counteract for AM/AM and AM/PM non-linearities, and by RF compensation techniques to remove Non Linear Memory effects.


Memory Effect Orthogonal Frequency Division Multiplex Signal Digital Video Broadcasting OFDM Signal Memory Distortion 
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  1. 1.
    W Honcharenko et al., “Broadband Wireless Access”, IEEE Communications Magazine, Vol. 35, No 1, Jenuary 1997 pp. 20–26Google Scholar
  2. 2.
    CRL, FUB et al., CABSINET ACTS Project, D21.1 State of the Art Report, Limited DeliverableGoogle Scholar
  3. 3.
    DVB, “Framing Structure, Channel Coding and Modulation for Digital Terrestrial Television”, DVB Document A012, June 1996.Google Scholar
  4. 4.
    ETS 300 401, “Radio Broadcasting Systems; Digital Audio Broadcasting ( DAB) to mobile portable and fixed receivers”, February 1995, pp 180.Google Scholar
  5. 5.
    A.R. Kaye, D.A. George, M.J. Eric, “Analysis and Compensation of Bandpass Nonlinearities for Communications”, IEEE Trans, on Comm., VOL. COM-20, October 1972, pp. 965–972.Google Scholar
  6. 6.
    M. Schetzen, “The Volterra and Wiener theories of nonlinear systems”, New York, Wiley & Sons 1980zbMATHGoogle Scholar
  7. 7.
    E. Biglieri, S. Barberis, M. Catena, “Analysis and compensation of nonlinearities in digital transmission systems”, IEEE JSAC, Vol. SAC-8, n.l, Jan 1988, pp. 42–51.Google Scholar
  8. 8.
    A. Sarti, S. Pupolin, “Recursive Techniques for the Synthesis of a pth-order inverse of a Volterra System”, ETT Vol. 3 n.4, Jul/Aug. 1992, pp. 315–322.Google Scholar
  9. 9.
    A.A.M.Saleh and J.Salz, “Adaptive Linearisation of Power Amplifiers in Digital Radio Systems”, The Bell Syst. Tech. Journal, Vol. 62, No. 4, April 1983, pp. 1019–1033.Google Scholar
  10. 10.
    J.K.Cavers, “Amplifiers Linearization Using a Digital Preedistorter with Fast Adaptation and Low Memory Requirements”, IEEE Trans, on Veh. Tech., Vol. VT-39, No. 4, November 1990, pp. 374–382.CrossRefGoogle Scholar
  11. 11.
    G.Karam and H.Sari, “Generalised Data Predistortion Using Intersymbol Interpolation”, Philips Res. Journal, Vol. 46, 1991, pp. 1–22.Google Scholar
  12. 12.
    M. Faulkner, M. Yohansson, “Adaptive Linearization Using Predistortion - Experimental Results”, IEEE Trans, on Veh. Tech., Vol. VT-43 n. 2, May. 1994, pp. 323–332.CrossRefGoogle Scholar
  13. 13.
    S.Andreoli, P.Banelli, S.Cacopardi, H.G. McClure, “Digital Linearizer for RF Amplifiers”, IEEE Trans, on Broad., Vol. 43, No 1 March 1997, pp 12–19.CrossRefGoogle Scholar
  14. 14.
    J. Rinne, and M. Renfors, “The Behaviour of Orthogonal Frequency Division Multiplexing Signals in Amplitude Limiting Channel”, IEEE International Conference on Communications (ICC ’94), New Orleans, USA, pp. 381–385.Google Scholar

Copyright information

© Springer-Verlag London Limited 1998

Authors and Affiliations

  • S Andreoli
    • 1
  • P Banelli
    • 2
  • A Longaroni
    • 1
  • C Massini
    • 1
  1. 1.Itelco R&DOrvieto (TR)Italy
  2. 2.Istituto di ElettronicaUniversità di PerugiaItaly

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