Performance Enhancement of Multi Band-OFDM Based Ultra Wide Band Systems for WPAN

Ultra wideband (UWB) technology is the foundation for future pervasive, wireless personal area networks (WPANs). The ability of UWB to utilize a large spectrum and thereby provide higher data rates, neither with the expense of multiple antennas nor the power requirements of narrow band transmissions, makes it ideal for low cost, high speed wireless communication. A detailed study of UWB properties in WPAN’s, provides a solution to certain key challenges. The high data rate demand of multimedia WPAN’s is achieved by utilizing the spectral resources efficiently. This requires UWB devices to be able to use the multiband-UWB (MB-UWB) technology with low complexity in low power systems. Accordingly, this paper proposes the use of UWB in the pulsed-OFDM system as an enhancement to incorporating LDPC coding and APSK modulation schemes that performs comparably to the existing system with low-complexity and power consumption. This thesis proposes the pulsed-OFDM modulation technique as an enhancement to the MB-OFDM system for UWB communications and also to reduce its power consumption and complexity. QPSK, QAM and DCM are the current modulation schemes used for MB-OFDM in the ECMA-368 standard which offers up to 480 Mbs instantaneous bit rate. Furthermore this paper proposes APSK modulation scheme that fits within the configuration of the current standard and increases the system throughput by achieving 960 Mbs. Practical UWB devices are limited to simple coding techniques to minimize both power consumption and device cost. LDPC codes have advantages with respect to the system complexity and hence they are utilized in designing the system.