Dynamic water-filling for wavelet communications

Multimedia communication is one of the main goals for the development of the third generation wireless communication system. Wavelets are known to provide better flexibility on handling multi-rate data. However, the frequency-selective and the time-varying nature of the wireless channels inevitably cause intercarrier interference (ICI) among wavelets. To solve the problem, we propose a unitary mapping filter on wavelets to achieve the optimum water-filling solution. Simulations compare the performance of the communication system using the proposed algorithm with the conventional direct sequence code division multiple access (DS-CDMA) system and the wavelet communication system with no unitary mapping filters, and confirm significant advantages of the proposed algorithm.