Maximum Likelihood Multiple Access Timing Synchronization for UWB Communications

Rapid and reliable timing synchronization is a demanding task in the receiver design for ultra-wideband (UWB) communication systems, especially when concurrent multiple access is called for. This paper derives a maximum likelihood based timing synchronization scheme for UWB multiple access. Relying on a set of user-specific training sequences, the novel concept of weighted average template is introduced, leading to a multiple access timing synchronizer that works in the absence of any channel knowledge and is resilient to both multiple access interference and noise. Simulation runs testify the effectiveness of the proposed scheme in terms of mean square timing estimation errors and bit-error-rate detection performance when operating in multiple access and dense multipath scenarios.