Millimeter accuracy UWB positioning system using sequential sub-sampler and time difference estimation algorithm

A compact sequential sampling scheme using a high sampling rate analog digital converter (ADC) and direct digital synthesis (DDS) technology has been proposed for the millimeter accuracy UWB positioning system, which can achieve the equivalent of a 100 GHz sampling rate. The analog bandwidth, frequency resolution, and time jitter of the sampler for UWB signal acquisitions are detailed. Based on the sampled UWB signal, a modified correlation algorithm for time difference estimation is proposed to further improve positioning accuracy and reduce the computational burden. Simulation results based on IEEE802.15.4a channel models and experiments utilizing the proposed sub-sampler show that our UWB positioning system can achieve up to millimeter accuracy.