Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30835
Adaptive Square-Rooting Companding Technique for PAPR Reduction in OFDM Systems

Authors: Wisam F. Al-Azzo, Borhanuddin Mohd. Ali


This paper addresses the problem of peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. It also introduces a new PAPR reduction technique based on adaptive square-rooting (SQRT) companding process. The SQRT process of the proposed technique changes the statistical characteristics of the OFDM output signals from Rayleigh distribution to Gaussian-like distribution. This change in statistical distribution results changes of both the peak and average power values of OFDM signals, and consequently reduces significantly the PAPR. For the 64QAM OFDM system using 512 subcarriers, up to 6 dB reduction in PAPR was achieved by square-rooting technique with fixed degradation in bit error rate (BER) equal to 3 dB. However, the PAPR is reduced at the expense of only -15 dB out-ofband spectral shoulder re-growth below the in-band signal level. The proposed adaptive SQRT technique is superior in terms of BER performance than the original, non-adaptive, square-rooting technique when the required reduction in PAPR is no more than 5 dB. Also, it provides fixed amount of PAPR reduction in which it is not available in the original SQRT technique.

Keywords: OFDM, complementary cumulative distribution function(CCDF), peak-to-average power ratio (PAPR), adaptivesquare-rooting PAPR reduction technique

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1849


[1] H. Schulze and C. L¨uders, Theory and Applications of OFDM and CDMA: Wideband Wireless Communications, Wiley, 2005.
[2] Y. Kim and R. Prasad, 4G Roadmap and Emerging Communication Technologies, Artech House, 2006.
[3] A. R. Bahai et al, "A new approach for evaluating clipping distortion in multicarrier systems," IEEE J. Selec. Area Commun., vol. 20, no. 5, pp. 1037-1046, June 2002.
[4] S. Miller and R. O-Dea, "Peak power and bandwidth efficient linear modulation," IEEE Trans. Commun., vol. 46, no. 12, pp. 1639-1648, Dec. 1998.
[5] H. Ochiai, "Power efficiency comparison of OFDM and single-carrier signals," Proc. IEEE VTC, vol. 2, Sept. 2002, pp. 899-903.
[6] X. Li and L. Cimini, "Effect of clipping and filtering on the performance of OFDM," IEEE Commun. Lett., vol. 2, no. 5, pp. 131-133, May 1998.
[7] H. Chen and M. Haimovish, "Iterative estimation and cancellation of clipping noise for OFDM signals," IEEE Commun. Lett., vol. 7, no. 7, pp. 305-307, July 2003.
[8] T. Jiang and G. Zhu, "Nonlinear companding transform for reducing peak-to-average power ratio of OFDM signals," IEEE Trans. broadcast., vol. 50, no. 3, pp. 342-346, Sept. 2004.
[9] S. H. M├╝ller and J. B. Huber, "OFDM with reduced peak-to-average power ratio by optimum combination of partial transmit sequences," Elect. Lett., vol. 33, no. 5, pp. 368-369, Feb. 1997.
[10] L. Cimini and N. Sollenberger, "Peak-to-average power ratio reduction of an OFDM signal using partial transmit sequences," IEEE Commun. Lett., vol. 4, no. 3, pp. 86-88., March. 2000.
[11] Y. Xiao, X. Lei, Q. Wen, and S. Li, "A class of low complexity PTS techniques for PAPR reduction in OFDM systems," IEEE Signal Proc. Lett., vol. 14, no. 10, pp. 680-683, Oct.2007.
[12] X. Zhu, T. Jiang, and G. Zhu, "Novel schemes based on greedy algorithm for PAPR reduction in OFDM systems, "IEEE Trans. Consm. Electr., vol. 54, no. 3, pp. 1048-1052, Aug.2008.
[13] Wisam F. Al-Azzo, Borhanuddin M. Ali, Sabira Khatun, and Syed M. Bilfagih, "Time domain statistical control for PAPR reduction in OFDM system", Proc. IEEE APCC 2007, Bangkok, Thailand, 2007, pp.141- 144.
[14] H. Ochiai and H. Imai, "Performance of the deliberate clipping with adaptive symbol selection for strictly band-limited OFDM systems," IEEE J. Select. Areas. Comm., vol. 18, no. 11, pp. 2270-2277, Nov. 2000.
[15] J. G. Proakis, Digital Communications, Mc-Graw Hill, 2001.
[16] S. Haykin and M. Moher, Modern Wireless Communications, Prentice Hall, 2005.