Wavelet based modulation for frequency hopped spread spectrum communications

Wavelet properties such as orthogonality over scale and translation make them well suited as modulation waveforms in a communication system. In this paper, we analyze the performance of a wavelet based FH-CDMA system operating in a multipath Rayleigh fading channel. In a frequency selective channel, unequal pulse widths of the dyadic wavelet functions introduce ISI with the short duration pulses being affected more than the long duration pulses. To combat the ISI, we employ a single multi-band equalizer before the wavelet transform and multiple single-band equalizers after the wavelet transform. It is shown that identical performance in terms of probability of bit error is obtained with both approaches; however, the computational complexity of single-band equalizers is smaller