Wavelet Based Multicarrier Modulation (MCM) Systems: PAPR Analysis

Abstract

Orthogonal frequency division multiplexing (OFDM) is a prominent system in transmitting multicarrier modulation (MCM) signals over selective fading channel. The system offers to attain a higher degree of bandwidth efficiency, higher data transmission, and robust to narrowband frequency interference. However, it incurs a high peak-to-average power ratio (PAPR) where the signals work in the nonlinear region of the high-power amplifier (HPA) results in poor performance. Besides, an attractive dynamic wavelet analysis and its derivatives such as wavelet packet transform (WPT) demonstrates almost the same criteria as the OFDM in MCM system. Wavelet surpasses Fourier based analysis by inherent flexibility in terms of windows function for non-stationary signal. In wavelet-based MCM systems (wavelet OFDM (WOFDM) and Wavelet packet OFDM (WP-OFDM)), the constructed orthogonal modulation signals behaves similar to the fast Fourier transform (FFT) does in the conventional OFDM (C-OFDM) system. With no cyclic prefix (CP) need to be applied, these orthogonal signals hold higher bandwidth efficiency. Hence, this chapter presents a comprehensive study on the manipulation of specified parameters using WP-OFDM, WOFDM and C-OFDM signals together with various wavelets under the additive white Gaussian noise (AWGN) channel.

Filtered-orthogonal wavelet division multiplexing (F-OWDM) technique for 5G and beyond communication systems

“…Each wavelet of the discrete wavelet family consists of two basis functions called the mother wavelet ( ) and the scaling function ( ) as shown in ( 1 ) and ( 2 ), respectively. Thus, the process of discrete scaling and translation of can be represented as in ( 3 ): where j and k are integers which indicate the scale and translation indices, is a fixed dilation step and is the translation factor 30 , 35 . The important features of a signal can be better described using the scaling functions and wavelets which are orthogonal to each other 32 .…”

“…It was proved that OWDM is one of the best MCM techniques that can provide much higher spectrum efficiency, reduce the ISI and ICI, and provide the best PAPR and BER performance in comparison with C-OFDM (Please note: In this article, we use conventional OFDM (C-OFDM) for DFT-OFDM (discrete Fourier transform-OFDM) and conventional F-OFDM (C-F-OFDM) for F-DFT-OFDM.) 28 – 30 . This motivates us to investigate this method on the C-F-OFDM system for improving the system performance.…”