%0 Journal Article
%T PAPR Reduction Approach Based on Channel Estimation Pilots for Next Generations Broadcasting Systems
%A Anh-Tai Ho
%A Jean-Fran£żois Helard
%A Youssef Nasser
%A Yves Louet
%J International Journal of Digital Multimedia Broadcasting
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/365896
%X A novel peak-to-average power ratio (PAPR) reduction technique for orthogonal frequency division multiplexing (OFDM) systems is addressed. Instead of using dedicated pilots for PAPR reduction as with tone reservation (TR) method selected by the DVB-T2 standard, we propose to use existing pilots used for channel estimation. In this way, we avoid the use of reserved tone pilots and then improve the spectral efficiency of the system. In order to allow their recovery at the receiver, these pilots have to follow particular laws which permit their blind detection and avoid sending side information. In this work, we propose and investigate a multiplicative law operating in discrete frequency domain. The operation in discrete domain aims at reducing degradation due to detection and estimation error in continuous domain. Simulation results are performed using the new DVB-T2 standard parameters. Its performance is compared to the DVB-T2 PAPR gradient algorithm and to the second-order cone programming (SOCP) competitive technique proposed in the literature. We show that the proposed technique is efficient in terms of PAPR reduction value and of spectral efficiency while the channel estimation performance is maintained. 1. Introduction orthogonal frequency division multiplexing (OFDM) technology has been the subject of numerous dissertations in recent years, mainly due to its several advantages for mobile wireless communications. It has been adopted in several systems mainly in digital video broadcasting (DVB) standards [1¨C3]. However, a main drawback of OFDM technique is the high peak-to-average power ratio (PAPR) of the transmitted signal. High PAPR value implies sophisticated and, thus, expensive radio transmitters with high-power amplifiers (HPAs) operating on a very large linear range at the transmitter side. Moreover, the nonlinearity of the HPA leads to in-band distortion, which increases the bit error rate (BER) of the system, and to out-of-band (OOB) distortion, which introduces high adjacent channel interference. Various approaches have been proposed as summarized in [4, 5] to mitigate the PAPR of an OFDM signal. Among them, clipping and filtering technique is easy to implement. However, these schemes yield a broken system performance since clipping is a nonlinear process [6] leading to a signal distortion. An alternative method based on coding was proposed in [7], in which a data sequence is embedded in a longer sequence, and only a subset of all these possible sequences is used to exclude patterns generating high PAPR. Moreover, other methods such as
%U http://www.hindawi.com/journals/ijdmb/2011/365896/