On calculating the distribution of the peak-to-average power ratio in OFDM systems
Orthogonal frequency division multiplexing (OFDM) is a promising framework for future wireless communication systems. One of the main impediments that has limited the applicability of OFDM systems in low-power wireless communication systems is the highly variable amplitude of the baseband transmitted signal; thus, a number of recent analyses have characterized this variation. These analyses have generally employed the following two components: (1) the assumption that the complex envelope of the OFDM signal converges to a Gaussian random process in some sense as the number of subcarriers becomes large, and (2) Rice's classical results on level-crossing rates for the envelope of Gaussian random processes. In this work, we improve on both of these components to arrive at a simple, accurate, and rigorously-established expression for the peak distribution of the envelope of an uncoded OFDM system with an unequal power distribution across subcarriers. The important extension to coded OFDM systems is also considered. Numerical results for all of these cases establish that the simple expressions obtained for the distributions of the peaks of the envelope process are extremely accurate, even for a modest number of subcarriers.
Publication Source (Journal or Book title)
Proceedings of the International Conference on Telecommunications
Wei, S., Goeckel, D., & Kelly, P. (2002). On calculating the distribution of the peak-to-average power ratio in OFDM systems. Proceedings of the International Conference on Telecommunications, 2, 585-589. Retrieved from https://digitalcommons.lsu.edu/eecs_pubs/1260