A MB-PULSED-OFDM System using DWPT for UWB WPAN Environment: Ultrawideband Communication

Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) approach using UWB signals with short duration of pulses provide unique advantages in short-range high data rate WPAN physical layer applications, which include easy penetration through obstacles, high precision ranging and low processing power. Non-pulsed MB-OFDM system suffers from the frequency selectivity of the fading channels. MB-pulsed-OFDM is used eliminate heavy error correction coding for dense multipath frequency selective channel model. The IFFT module in the pulsed-OFDM transmitter is much less complex than the IFFT module in the normal OFDM because MB-pulsed-OFDM uses 32 subcarriers while normal MB-OFDM uses 128 sub-carriers. Each subcarrier has large side-lobes, requiring careful filtering and sufficient guard interval bands in a traditional MB-OFDM UWB system. Again Fourier based MB-OFDM signals only overlap in frequency domain. To overcome these aforementioned problems associated with MB-OFDM UWB system, a finer and adjustable resolution of frequencies at high frequency is presented as wavelet basbased transform technique i.e. discrete wavelet packets transform (DWPT) instead of using FFT.jai jagannath