Discrete wavelet transforms in multi-carrier modulation

Multi-carrier modulation (MCM) is increasingly popular as a transmission technique, especially in high speed communications. One implementation of MCM is discrete multi-tone (DMT) modulation using the discrete Fourier transform (DFT) for modulation. DMT is adopted as a standard by the ANSI for asymmetric digital subscriber line (ADSL). It has been suggested that discrete wavelet transform (DWT) in the form of perfect reconstruction (PR) filter banks be used in place of DFT as modulation functions. The advantage of such replacement is better spectral containment in PR filter banks than in DFT. This paper describes a form of PR filter banks, the cosine-modulated FIR filter banks, to be used for multi-carrier modulation. A system using this filter is described and its performance is evaluated and comparison is made with the DMT system.