New results on the peak power of OFDM signals based on oversampling

Abstract

In this paper, we introduce a new bound for the peak of the continuous envelope of an OFDM signal based on the maximum of its corresponding oversampled sequence, that is considerably tighter than the recent results presented in Sharif and Khalaj (2001). The proposed bound is then used as the basis of our study in two parts. In the first part, we find an upper bound for the regrowth of the peak of the digitally clipped oversampled sequence after discrete to continuous conversion. We also show that for oversampling rates greater than /spl pi///spl radic/2, the peak regrowth percentage depends only on oversampling rate, regardless of the number of subcarriers. In the second part, we propose new and tight relative error bounds for computation of the peak power using two main methods: the oversampled inverse fast Fourier transform (IFFT) and the method introduced for coded systems by Tarokh and Jafarkhani (2000).