Text

theses

WPAN systems have been receiving significant attention from both industry and academia in the last 10 years and Ultra Wide Band (UWB) technology is one among them. Nowadays, UWB systems can transmit at a data rate as high as 500 Mbps for short distances consuming very little power. When a UWB system moves from the laboratory environment to a real world scenario, several design issues are encountered such as complexity, power consumption, cost and flexibility. In this thesis, a UWB system is designed using a Multiband OFDM physical layer approach which tackles the problems mentioned above while still ensuring high data rates with less power consumption. The reason for choosing this approach over a traditional spread spectrum approach is that the system sends the signal on several sub-bands one at a time making it spectrally flexible while using lesser bandwidth and, hence, preventing the need for high speed RF circuits and ADC’s. This will reduce the design complexity and, thereby, reducing the power consumption and making this technology a low cost solution. Since the information on each of these bands uses a multicarrier (OFDM) technique, this system inherits several nice properties of OFDM such as high spectral efficiency, resilience to RF interference, robustness to multi-path, and the ability to efficiently capture multi-path energy. This thesis focuses on optimizing the Bit Error Rate (BER) performance of the system by making use of symbol diversity and multicarrier diversity techniques. Symbol diversity is implemented by sending an OFDM symbol on different sub-bands and improve the BER by combining the outputs using Maximal Ratio Combining. In multicarrier diversity, the performance is improved further by sending the same data on different subcarriers in an OFDM signal. In addition, a study of the performance by sending the data sensibly on different subcarriers in an OFDM symbol using prior channel information is conducted. The various blocks needed to design the transmitter chain and the receiver chain of the system were implemented using a LabVIEW software testbed and a frequency selective fading channel suggested by the UWB standards committee was simulated to study the performance of the system.

ETD_4739

M.S.

Includes bibliographical references

by Swaminathan Duraisamy

http://hdl.rutgers.edu/1782.1/rucore10001600001.ETD.000068847

doi:10.7282/T3P26WQF

ETD graduate

The author owns the copyright to this work.