Summary: Efficient Algorithms for PAPR Reduction in OFDM
Transmitters Implemented using Fixed-Point DSPs
Brendon Schmidt', Chi Ng', Patrick Yien', Christina Harris', Ushodaya Saripalle, Andrew Price', Simon Brewer2,
Giuseppe Scelsi2, Robert Slaviero2 and Jean Armstrong'
'Department ofElectrical and Computer Systems Eng.
Clayton, Victoria 3800, Australia.
Abstract-OFDM has a very high peak-to-average power ratio.
This imposes stringent dynamic range requirements on the
analog front-ends of the transmitter and receiver and, if a fixed-
point processor is used, on the digital sections of the system,
particularly the FFT/IFFT. OFDM systems often use digital peak
reduction techniques such as clipping and filtering but these
require several FFT/IFFT operations. In this paper results are
presented for the combination of a novel FFT algorithm which
allows numeric overflow to occur with low probability, and
several computationally efficient clipping techniques. Results are
presented for the mean-square error of the clipped and filtered
OFDM signal and for the computational complexity of the system