OFDM is one of the promising techniques for achieving high downlink capacities in future cellular and wireless networks.The major problem of orthogonal frequency division multiplexing (OFDM) signals is high peak to average power ratio (PAPR) of the transmitted signal. A high PAPR brings disadvantages like an increased complexity of the A/D and D/A converters and reduced efficiency of radio frequency (RF) power amplifier. The high peak of OFDM signal can be reduced by PAPR reduction techniques. In this paper partial transmit sequences (PTS) and iterative flipping schemes are discussed to reduce PAPR and compared with original scheme (without PAPR reduction scheme). Computer Simulations results show that the both schemes achieve PAPR reductions, but the result shows that PTS scheme can offer better PAPR reduction performance than the iterative flipping.

1. Xiaodong Zhu, Student Member, IEEE, Tao Jiang, Member, IEEE, and Guangxi Zhu, Senior Member, IEEE, “Novel Schemes Based on Greedy Algorithm for PAPR Reduction in OFDM Systems,” IEEE Transactions on Consumer Electronics, Vol. 54, No. 3, AUGUST 2008.
2. Yajun Kou, Student Member, IEEE, Wu-Sheng Lu, Fellow, IEEE, and Andreas Antoniou, Fellow, IEEE,“New Peak-to-Average Power-Ratio Reduction Algorithms for Multicarrier Communications,”IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—I: REGULAR PAPERS, VOL. 51, NO. 9, SEPTEMBER 2004 .
3. X. Li and L. J. Cimini, Jr., “Effect of Clipping and Filtering on the Performance of OFDM,”IEEE Communication Letters, vol. 2, no. 5, pp. 131-133, May 1998.
4. T. Jiang and G. X. Zhu. “Nonlinear Companding Transform for Reducing Peak-to-Average Power Ratio of OFDM Signals;” IEEE Transactions on Broadcasting, vol. 50, no. 3, pp. 342-346, Sept. 2004.
5. H. G. Ryu, T. P. Hoa, N. T. Hieu, and J. Jin, “BER Analysis of Clipping Process in the Forward Link of the OFDM-FDMA Communication System,” IEEE Transactions on Consumer Electronics, vol. 50, no.4, pp. 1058-1064, Nov. 2004.
6. R. W. Bäuml, R. F. H. Fisher, and J. B. Huber, “Reducing the Peak-to-Average Power Ratio of Multicarrier Modulation by Selected Mapping,” Electronics Letters, vol.32, no. 22, pp. 2056-2057, Oct. 1996.
7. S. H. Müller, J. B. Huber, “OFDM with Reduced Peak–to–Average Power Ratio by Optimum Combination of Partial Transmit Sequences,” Electronics Letters, vol. 33, no. 5, pp. 368-369, Feb. 1997.
8. J. Tellado. Peak to average power ratio reduction for multicarrier modulatio; PhD thesis, University of Standford, 1999.
9. S. Yoo, S. Yoon, S. Y. Kim, and I. Song, “A Novel PAPR Reduction Scheme for OFDM Systems: Selective Mapping of Partial Tones (SMOPT)”, IEEE Transactions on Consumer Electronics, vol. 52, no.1, pp. 40-43, Feb. 2007.
10. L. J. Cimini, Jr. and N. R. Sollenberger, “Peak-to-average power ratio reduction of an OFDM signal using partial transmit sequences,” IEEE Communication Letters., vol. 4, no. 3, pp. 86-88, Mar. 2000.
11. C. Tellambura, “Computation of the continuous-time PAR of an OFDM signal with BPSK subcarriers,” IEEE Communication Letters, vol. 5, no. 5, pp. 185-187, May 2001.
12. P. Mukunthan , P.Dananjayan,“Modified PTS with FECs for PAPR Reduction of OFDM Signals,” International Journal of Computer Applications (0975 – 8887) Volume 11– No.3, December 2010.
13. S. H. Muller and H. B. Huber, “OFDM with reduced peak-to-mean power ratio by optimum combination of partial transmit sequences,” Electronics Letters, vol. 33, pp. 368-369, Feb. 1997

Orthogonal frequency division multiplexing (OFDM) partial transmit sequence (PTS) peak to average power ratio (PAPR) iterative flipping Analog to Digital converters Digital to Analog converters