AN ABSTRACT OF A THESIS THEORY AND APPLICATION OF TIME REVERSAL TECHNIQUE TO ULTRA WIDEBAND WIRELESS COMMUNICATIONS

Inter symbol interference (ISI) is a major obstacle for achieving low bit error rates in wireless communications. Orthogonal frequency division multiplexing (OFDM) and equalization techniques such as zero forcing (ZF) and minimum mean square error (MMSE) have been employed in combating ISI in typical wireless channels. In this research, a technique called time reversal was investigated as a possible means for achieving higher data rate for a given bit error rate (BER) in ultra wideband (UWB) communications. In this thesis work, time-reversal (TiR) technique was studied in detail and its application to UWB was fully evaluated. Different metrics for characterizing the space-time focusing properties of time reversal in UWB were proposed and evaluated. The technique employed used a time-domain sounding of the UWB channel to extract the channel impulse response (CIR). UWB channels are measured by sounding the channel with a sub-nanosecond pulse. CLEAN algorithm was then used to extract the CIR from the received waveform. From the observed channel impulse response, the leverages and applications of TiR in UWB were then demonstrated