PAPR reduction of wavelet-OFDM systems using pilot symbols

Wavelet transform is at the heart of IEEE 1901 power line communication standard which uses orthogonal frequency-division multiplexing (OFDM) scheme. Examples of wavelets used in designing wavelet-based OFDM (WOFDM) have been shown as possessing lower peak-to-average power ratio (PAPR) than the conventional fast Fourier transform (FFT)-based OFDM. In this study, we investigate 29 different orthogonal wavelets that can be used in designing WOFDM in terms of PAPR and sidelobes behaviour of the filters that enable these wavelets. Our WOFDM model shows that most orthogonal wavelets with increasing filter coefficient lengths achieve better PAPR. In addition, we also demonstrate a method of pilot-assisted OFDM (PA-OFDM) processing to further reduce the PAPR of the WOFDM systems. This technique achieves PAPR reduction with no added complexity and no extra bandwidth cost.