Reduced complexity impulse radio ultra wide band direction finding systems

Abstract

The research works presented in this thesis are motivated by the low complexity and high accuracy capabilities of UWB Impulse Radio (IR) systems. In particular, this thesis addresses UWB IR direction finding (DF) system designs using a reduced complexity receiver structure. The first contribution of the thesis is the DF receiver using digital channelization receiver architecture, where the use of Nyquist rate sampling is no longer required. In a multipath environment, this approach requires a multipath suppression technique. Due to the low complexity constraint, we propose a simple analog level threshold detector (LTD). Performance analysis reveals that the error in detection due to the LTD will give rise to the estimation errors. An alternative means for DF is using a simple analog differentiator with a peak-and-hold detector. This approach is motivated by the observation of a staircase-shape waveform whose slope indicates the direction of arrival (DOA). In view of the error from the LTD’s operation, we propose a time-delay-based DF system. The DF is calculated from the time delay estimates from each channel of the array. Lastly, we extend the DF problem from single source to multiple sources transmission, using Time Hopping Multiple Access scheme.