Timing Acquisition for UWB Multiple Access

For ultra-wideband (UWB) multiple access communications, a critical task in receiver design is to attain rapid and accurate timing synchronization in the presence of multiple access interference (MAI) and dense multipath fading, and subject to stringent constraints on complexity. To this end, this paper devises a GLRT-based novel timing acquisition method to be employed in multiple access UWB ad-hoc networking, wherein more than one node may request for simultaneous medium access. The key step builds on the noisy template concept that proves to be efficient in collecting full multipath diversity, but becomes quite inadequate when MAI is present. Tailored to multiple access scenarios, this paper employs a set of user-specific training symbols to construct a new weighted average noisy template, which makes the resulting timing estimation algorithm to be effectively resilient to both MAI and noise, and even independent of the channel knowledge. Simulations results confirm that the proposed timing technique has good performances in realistic multiple access and dense multipath environments.