Characterization of the Ultra-Wide Band Channel
Abstract
Ultra Wide Band (UWB) is an emerging wireless technology. It is referred to as baseband, impulse or carrier-free, and it has been proposed for unlicensed operations over bandwidth spanning several GHz, provided the power spectral density of transmitted signals are adherent to some emission masks (as specified by the Federal Communication Commission in the USA) suggested by coexistence issues with other systems [1]. Due to its extreme flexibility, UWB is currently considered by the research community worldwide for many applications, ranging from short range/high rate data communications in WPAN to low-cost/low-power networking in wireless sensor networks. Unlike narrow-band channels, UWB channels exhibit two main effects: multipath propagation and pulse distortion. In particular, during propagation each waveform can be rejected by an object or can penetrate through a material, thus leading to multipath propagation. Each of these efforts is frequency sensitive and therefore the waveform is fitered in some way, thus resulting in a multipath component with different pulse shape. From these considerations, it follows that UWB channels are frequency selective even if the channel consists of only a single path, thus significantly altering the shape of the transmitted pulse. The channel model described in does not explicitly account for the effect of waveform distortion and the proposers only suggest to include the additional losses due to waveform distortion in the link budget margin. In this paper we intend to investigate about the frequency selective effects of common building materials in the frequency band where UWB systems are allowed to operate 3.1-10.6 GHz [1], thus deriving an UWB channel model composed by a cascade of two linear (eventually time-variant) systems that accounts for the two aspects mentioned above (i.e. multipath propagation and pulse distortion).
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA449831
Entities
People
- Fabio Graziosi
- Fortunato Santucci
- Giuliano Manzi
- Marco Di Renzo
- Mauro Feliziani