UC San Diego
Analysis of impulse radio ultra-wideband systems
- Author(s): Sabattini, Matteo
- et al.
Ultra-wideband communications are gaining popularity for future indoor wireless high-speed/low-power transmissions, thanks to their versatility and technological features. At the same time, the unlicensed spectrum allocated for ultra -wideband transmissions impose stringent constraints on power emission, as well as coexistence capabilities with other commercial systems. Many technical issues are still open at the present time: the extremely wide bandwidth results in a large number of resolvable multipaths, and, consequently, a high receiver complexity. Furthermore, ultra-wideband systems have to coexist with other ultra- wideband devices, as well as other narrow-band commercial systems. This dissertation addresses some of these issues, and sketches some possible solutions. First, a novel analytical technique is introduced, in order to accurately model the interference at the receiver from other ultra- wideband devices. Second, beamforming techniques are analyzed, in order to mitigate the effect of the aforementioned MAI, as well as the interference from narrow-band commercial systems and jammers. Another open issue for ultra-wideband devices deals with synchronization and acquisition in harsh multipath environments, and in the presence of narrow-band interference. A technique to jointly estimate the channel attenua-ion and acquire code synchronization, based on an approximation of the maximum likelihood criterion, is presented and analyzed