Title
Channel Uncertainty in Ultra-Wideband Communication Systems
Abstract
Channel uncertainty limits the achievable data rates of certain ultra-wideband systems due to the need to estimate the channel. The use of bursty duty-cycled transmission reduces the channel uncertainty because the receiver has to estimate the channel only when transmission takes place, but the maximum amount of burstiness and hence the possible reduction of channel uncertainty both depend on the spectral efficiency of the modulation scheme used. This general principle is demonstrated by comparing the channel conditions that allow duty-cycled direct-sequence spread spectrum (DSSS) and pulse position modulation (PPM) to achieve the additive white Gaussian noise (AWGN) channel capacity in the wideband limit. We show that duty-cycled DSSS systems achieve the wideband capacity as long as the number of independently faded resolvable paths increases sublinearly with the bandwidth, while duty-cycled PPM systems can achieve the wideband capacity only if the number of paths increases sublogarithmically. The difference is due to the fact that DSSS is spectrally more efficient than PPM and hence allows more bursty transmission
Year
DOI
Venue
2005
10.1109/TIT.2006.887063
IEEE Transactions on Information Theory
Keywords
DocType
Volume
ultra-wideband communication systems,duty-cycled ppm system,wideband capacity,bursty duty-cycled transmission,channel uncertainty,duty-cycled dsss system,channel capacity,wideband limit,channel condition,modulation scheme,bursty transmission,code division multiple access,additive white gaussian noise,ppm,ultra wide band,duty cycle,spectral efficiency,spread spectrum communication,dsss,direct sequence spread spectrum,pulse position modulation
Journal
53
Issue
ISSN
Citations 
1
0018-9448
12
PageRank 
References 
Authors
0.80
6
3
Name
Order
Citations
PageRank
Porrat, D.1495.51
David Tse2101821122.05
S. Nacu3120.80