Blind timing and channel estimation for UWB multiuser ad hoc access

One of the major challenges at the physical layer of an ultrawideband (UWB) network is the accuracy and speed of the synchronization and channel estimation tasks. Especially in ad hoc multiaccess scenarios, acquiring timing and channel information blindly is instrumental for user separation and bandwidth efficient demodulation. Relying on intermittently transmitted asymmetric pulse-amplitude modulated (PAM) signals, we derive novel blind timing and channel estimators for UWB point-to-point and multiaccess communication links for use in ad hoc networks. Both intersymbol interference (ISI)-free as well as ISI channels are considered. Comparisons are provided and performance of the resultant algorithms is evaluated analytically and with bit-error rate (BER) simulations.