Peak to average power ratio in amplitude clipped high order OFDM

One of the main problems of orthogonal frequency division multiplexing (OFDM) is the large peak-to-average power ratio (PAPR) of the output signal which demands linear behavior of the system over a large dynamic range. In this paper the performance of amplitude clipped high order OFDM is considered. Using a central limit theorem, the distribution of the OFDM signal is found to be asymptotically Gaussian when the order of the OFDM signal approaches infinity. An expression for the probability that the PAPR of the signal will exceed a given level is found, and using it an upper bound on the BER is derived. It is shown that when the clipping level approaches infinity faster than /spl radic/(ln N), then a zero BER penalty and arbitrarily large peak-to-average power ratio gain are asymptotically obtained. It is also shown that use of the asymptotic results for N/spl ges/32 causes a negligible error in practice.