Tracking UWB monocycles in IEEE 802.15 multipath channels

This paper analyzes the variance of the timing error at the output of the timing error detector as a result of multipath effects. While G. Fock, et. al., (2001) and others have examined similar channel impairments on spread spectrum CDMA systems employing rake receiver with early-late timing detector, it is not known how severe multipath will affect UWB tracking loop. An UWB system transmitting impulses generally has considerably larger bandwidth and operates at higher frequencies mandated by FCC. Also, UWB impulse system utilizes short duration monocycles separated in time by the frame period unlike conventional continuous time signal. Thus, it has the advantage of being able to resolve more closely spaced multipaths than most other existing spread spectrum systems. Indeed, our analysis shows that, assuming clusters are well separated, and for channel parameters reported in J. Foerster et al., (2002), the self-interference due to rays in the same cluster may not be ´harmful´ for most applications.