SYNCHRONIZATION IN IMPULSE RADIO ULTRA-WIDEBAND COMMUNICATION SYSTEMS By SANDEEP AEDUDODLA A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA

of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy SYNCHRONIZATION IN IMPULSE RADIO ULTRA-WIDEBAND COMMUNICATION SYSTEMS By Sandeep Aedudodla December 2006 Chair: Tan F. Wong Major Department: Electrical and Computer Engineering Ultra-wideband (UWB) communication has recently generated a significant amount of interest and is a primary physical layer candidate for wireless personal area network (WPAN) standards aimed at both high data rate and low data rate applications. Ultra-wideband spread spectrum systems employing impulse radio signaling are being considered for these applications. The UWB channel is a dense multipath channel with a large delay spread and highly resolvable multipath components, owing to the narrow pulses employed. In any communication system, the receiver requires knowledge of the timing information of the received signal to accomplish demodulation. The process of obtaining this timing information is known as synchronization. Spread spectrum systems typically achieve synchronization in two stages: acquisition and tracking. The acquisition stage attempts to achieve coarse synchronization to within a chip duration by evaluating the phases in the search space and the tracking stage employs a code tracking loop to maintain fine synchronization. Ultra-wideband systems employ long spreading sequences to eliminate spectral lines resulting from pulse repetition. Moreover, the short pulses employed result in a fine resolution of the search space. Due to these reasons, UWB acquisition systems face a large search space which results in a large amount of time for