A New PAPR Reduction Technique for OFDM-WLAN in 802.11a Systems

In this paper, we proposed a new PAPR reduction technique using selective mapping (SLM) cascade with adaptive peak power reduction (APPR) methods. This technique is used in a system based on Orthogonal Frequency Division Multiplexing (OFDM). OFDM has many orthogonally modulated sub-carriers which unexpectedly produce high peak to average power ratio (PAPR). The high PAPR will occasionally reach the amplifier saturation region and therefore result in signal distortion, which causes bit error rate (BER) degradation. The proposed method, a sequence of input data is rearranged by SLM for the reduction of PAPR and then fed into the APPR process in the proposed system. The APPR method controls the peak levels of the modulation signal by an adaptive algorithm. It reduces modulation signals over a predefined range. The parameter for simulation used standard WLAN in IEEE 802.11a system. In simulation results, the proposed method shows the improvement on PAPR, power spectrum density (PSD) and high performance BER compared with conventional APPR.

[1]  Jae Hong Lee,et al.  An overview of peak-to-average power ratio reduction techniques for multicarrier transmission , 2005, IEEE Wireless Communications.

[2]  J. Tellado,et al.  Multicarrier Modulation with Low Par: Applications to DSL and Wireless , 2000 .

[3]  Kook-Yeol Yoo,et al.  A study on the PAR reduction by hybrid algorithm based on the PTS and SLM techniques , 2003, The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring..

[4]  G. Clark,et al.  Reference , 2008 .

[5]  R. Bäuml,et al.  Reducing the peak-to-average power ratio of multicarrier modulation by selected mapping , 1996 .

[6]  J.B. Huber,et al.  A comparison of peak power reduction schemes for OFDM , 1997, GLOBECOM 97. IEEE Global Telecommunications Conference. Conference Record.

[7]  Jae Hong Lee,et al.  Modified selected mapping technique for PAPR reduction of coded OFDM signal , 2004, IEEE Transactions on Broadcasting.

[8]  N.D. Gohar,et al.  Reducing peak-to-average power ratio (PAPR) using partial transmit sequence in OFDM systems , 2003, 7th International Multi Topic Conference, 2003. INMIC 2003..

[9]  B.J.A. Bassem,et al.  A PAPR Reduction Method for STBC MIMO-OFDM Systems Using SLM in Combination with Subband Permutation , 2007, 2007 Third International Conference on Wireless and Mobile Communications (ICWMC'07).

[10]  Y. Miyanaga,et al.  A new PAPR reduction in OFDM-WLAN systems by hybrid algorithm of PTS and APPR methods , 2007, 2007 Asia-Pacific Conference on Communications.