Peak-to-Average-Power-Ratio (PAPR) reduction in WiMAX and OFDM/A systems
1 Department of Signal and Systems, Chalmers University of Technology, P.C-412 96 Gothenburg, Sweden
2 ArrayComm, LLC, 2025 Gateway Place 348, San Jose, CA, 95110, USA
EURASIP Journal on Advances in Signal Processing 2011, 2011:38 doi:10.1186/1687-6180-2011-38Published: 9 August 2011
A peak to average power ratio (PAPR) reduction method is proposed that exploits the precoding or beamforming mode in WiMAX. The method is applicable to any OFDM/A systems that implements beamforming using dedicated pilots which use the same beamforming antenna weights for both pilots and data. Beamforming performance depends on the relative phase shift between antennas, but is unaffected by a phase shift common to all antennas. PAPR, on the other hand, changes with a common phase shift and this paper exploits that property. An effective optimization technique based on sequential quadratic programming is proposed to compute the common phase shift. The proposed technique has several advantages compared with traditional PAPR reduction techniques in that it does not require any side-information and has no effect on power and bit-error-rate while providing better PAPR reduction performance than most other methods.