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Model order selection for digital predistortion of a RF power amplifier when the distortion spectrum exceeds the observation bandwidth

Published online by Cambridge University Press:  26 February 2013

R. Neil Braithwaite
R. Neil Braithwaite*
Affiliation:
Powerwave Technologies, 1801 E. St. Andrew Place, Santa Ana, CA 92705, USA
*
Corresponding author: R. Neil Braithwaite Email: nbraithwaite@pwav.com
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Abstract

Digital predistortion (DPD) of a nonlinear power amplifier (PA) is made challenging when the observation bandwidth (OBW) used to measure the output signal is narrower than the intermodulation distortion (IMD) spectrum generated. Wide bandwidth input signals stimulate memory effects within the PA thereby requiring the model order of the DPD to be expanded to include memory correction coefficients. However, if the model order is over-specified relative to the OBW, the estimation of the DPD coefficients will be ill-conditioned and the distortion cancellation will be degraded. This paper proposes a method of selecting the best model order of the DPD coefficient estimation for the available OBW. Adjacent channel power ratio (ACPR) is used as an independent measure of the distortion cancellation for a given model order. Experimental results demonstrate the relationship between the model order of the estimation, the OBW, and the ACPR performance of the wide bandwidth IMD cancellation.

Keywords

amplifier distortioncommunication system nonlinearitiespower amplifier linearization
Type
Research Papers
Information
International Journal of Microwave and Wireless Technologies , Volume 5 , Special Issue 2: Special Issue on Power Amplifier Linearization , April 2013 , pp. 163 - 170
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2013

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References

REFERENCES

[1]3GPP TS 25.104 v8.6.0, Base station (BS) radio transmission and reception (FDD), Mar. 2009. Available at: www.3gpp.org.Google Scholar
[2]Braithwaite, R.N.: Wide bandwidth adaptive digital predistortion of power amplifiers using reduced order memory correction, 2008 IEEE MTT-S International Microwave Symp., Atlanta, GA, June 15–20, 2008, 1517–1520.Google Scholar
[3]Braithwaite, R.N.: General principles and design overview of digital predistortion, In Luo, F. (Ed.), Digital Processing for Front End in Wireless Communication and Broadcasting, Cambridge University Press, Cambridge, UK, 2011, 143–191.Google Scholar
[4]Cripps, S.C.: RF Power Amplifiers for Wireless Communications, Artech House, Norwood, MA, 1999.Google Scholar
[5]Zhu, A.; Pedro, J.C.; Cunba, T.R.: Pruning the Volterra series for behavioral modeling of power amplifiers using physical knowledge. IEEE Trans. Microw. Theory Tech., 55 (5) (2007), 813–821.Google Scholar
[6]Braithwaite, R.N.: Memory correction of a Doherty power amplifier with a WCDMA input using digital predistortion, 2006 IEEE MTT-S Int. Microwave Symp., San Francisco, CA, June 11–16, 2006, 1526–1529.Google Scholar
[7]Ding, L. et al. : A robust digital baseband predistorter constructed using memory polynomials. IEEE Trans. Commun., 52 (1) (2004), 159–165.Google Scholar
[8]Zhu, Y.-M.: Generalized sampling theorem. IEEE Trans. Circuits Syst.-II: Analog Digital Signal Process., 39 (8) (1992), 587–588.Google Scholar
[9]Braithwaite, R.N.: Reducing estimator biases due to equalization errors in adaptive digital predistortion systems for RF power amplifiers, 2012 IEEE MTT-S Int. Microwave Symp., Montreal, Canada, 17–22 June 2012, 1–3.Google Scholar
[10]Luenberger, D.G.: Linear and Nonlinear Programming, 2nd ed., Addison-Wesley, Reading, MA, 1984.Google Scholar