Acquisition of direct-sequence transmitted reference ultra-wideband signals

In this paper, we investigate the timing acquisition problem for transmitted reference (TR) ultra-wideband systems employing direct-sequence (DS) spreading. We show that a two-level DS signaling helps in achieving good acquisition performance. We propose a two-stage acquisition scheme which exploits the TR signal structure to achieve a significant improvement in the mean detection time performance when compared with a conventional single-stage acquisition scheme.