Paper Info
Title
Wideband fading channel capacity with training and partial feedback
Abstract
We consider the capacity of a wideband fading channel with partial feedback, subject to an average power constraint. The channel is modeled as a set of parallel independent block Rayleigh fading subchannels with finite coherence time (L channel uses). The transmitter probes a subset of subchannels during each coherence time by transmitting pilot sequences for channel estimation. For each subchannel probed, one bit of feedback indicates whether or not the channel gain exceeds a threshold allowing transmission. Our problem is to optimize jointly the training (both length and power), number of sub-channels probed (probing bandwidth), and feedback threshold to maximize the achievable rate (lower bound on ergodic capacity) taking into account the subchannel estimation error. Optimizing the probing bandwidth balances diversity against the quality of the subchannel estimate. We show that the achievable rate increases as S log L, where S is the signal-to-noise ratio, and exceeds the capacity with impulsive signaling (given by S) when L exceeds a (positive) threshold value. Moreover, the optimal probing bandwidth scales as S L/log2 L. In contrast, without feedback the optimal probing bandwidth for the probing scheme scales as SL1/3 and the achievable rate converges to S, where the gap diminishes as SL-1/3.
Year
DOI
Venue
2010
10.1109/TIT.2010.2059719
IEEE Transactions on Information Theory
Keywords
Field
DocType
log l,partial feedback,feedback threshold,wideband fading channel capacity,l channel,bandwidth balances diversity,channel gain,achievable rate,bandwidth scale,channel estimation,wideband fading channel,ultrawideband,feedback,coherence,radio transmitters,transmitters,rayleigh fading,fading channel,lower bound,broadband networks
Discrete mathematics,Wideband,Topology,Rayleigh fading,Telecommunications,Fading,Computer science,Signal-to-noise ratio,Communication channel,Bandwidth (signal processing),Channel capacity,Coherence time
Journal
Volume
Issue
ISSN
56
10
0018-9448
Citations 
PageRank 
References 
9
0.67
20
Authors
2
Name
Order
Citations
PageRank
Manish Agarwal133537.47
Michael L. Honig22971411.29