Fluid coding and coexistence in ultra wide band networks

Time Hopping Ultra Wide Band (TH UWB) commonly encodes the data symbols by shifting the position of the transmitted pulses by a quantity that is quantized over the inter-pulse interval range. In this paper, we relax the hypothesis of a discrete value for the time shift introduced by the TH code, by considering the possibility of generating real-valued codes that introduce time hopping in a fluid way. The effect on the power spectral density of generated signals is analyzed, and application of fluid coding to multiple access and to network coexistence is investigated by simulation. Index Terms Ultra Wide Band, Impulse Radio, Time Hopping coding, Multi-User UWB communications 1 Portions of this work were presented at the 2005 2 International Workshop Networking with Ultra Wide Band, Workshop on Ultra Wide Band for Sensor Networks [M.G. Di Benedetto, G. Giancola, D. Domenicali, and P. Ingargiola, Fluid Coding in Time Hopping Ultra Wide Band Networks, Proceedings of the IEEE 2nd International Workshop Networking with Ultra Wide Band Ultra Wide Band for Sensor Networks, July 2005, Rome, Italy].