Design challenges for very high data rate UWB systems

Ultrawideband (UWB) is a promising radio technology for networks delivering extremely high data rates at short ranges. In this paper, different approaches to the physical layer system design for such networks are studied, and some of the challenges and opportunities inherent in their design and implementation are compared. For example, the use of extremely short duration pulses offers great possibilities for position location, but makes the timing synchronization task more complex. The ultra-wide bandwidth offers excellent frequency diversity and multipath resolution, but the channel estimation and multipath combining tasks are correspondingly more challenging. A pulse based UWB system (or impulse radio, IR-UWB) and a novel pulsed multicarrier UWB system are compared, emphasizing timing acquisition and performance in multipath. Some other differences, including interference avoidance, equalization, etc. are briefly dealt with.