Wavelet-based Multicarrier Modulation Research Articles

Multirate signal processing techniques for high-speed communication over power lines

With the widespread use of Internet and multimedia applications, there is renewed interest in utilizing the electric power lines for transmission of high data rate communication signals. Power lines offer a convenient and pervasive communication medium that does not require new cable installation. However, power lines are classified as a noisy and unpredictable communication channel. Advanced signal processing techniques, such as wavelet filter banks and multirate systems, can be utilized to improve the quality of communication over power lines. In this article an overview of the diverse applications of wavelet filter banks in power line communications is presented with particular reference to wavelet-based multicarrier modulation techniques. Moreover, some suggestions are given regarding the future applications of multirate signal processing techniques in PLC.

Novel study on PAPRs reduction in wavelet-based multicarrier modulation systems

Utilizing the advantage of concentrating energy to certain subspaces of the discrete wavelet transform (DWT), a novel peak-to-average power ratio (PAPR) reduction method for wavelet-based multicarrier modulation (WMCM) systems is proposed and presented in this paper. Both theoretical analyses and simulations are carried out to prove the feasibility of the proposed method. PAPRs are investigated by employing different thresholds. The distortions of the wavelet transform caused by the threshold are measured in terms of the mean square error (MSE). This paper also investigates the bit error rate (BER) performance of threshold controlled WMCM systems. All results given in this paper are based on a limited class of wavelets. However, this method can be adapted to WMCM system with other kinds of wavelets as well, since almost all kinds of wavelets have this similar characteristic used in the threshold control method. Therefore, we conclude that the proposed threshold method is an efficient technique for WMCM systems.

A study on the PAPRs in multicarrier modulation systems with different orthogonal bases

AbstractThis paper studies the peak‐to‐average power ratios (PAPRs) in multicarrier modulation (MCM) systems with seven different orthogonal bases, one Fourier base and six wavelet bases. It is shown by simulation results that the PAPRs of the Fourier‐based MCM system are lower than those of all wavelet‐based MCM (WMCM) systems. A novel threshold‐based PAPR reduction method is then proposed to reduce the PAPRs in WMCM systems. Both numerical and simulation results indicate that the proposed PAPR reduction method works very effectively in WMCM systems. Copyright © 2006 John Wiley & Sons, Ltd.