Title
Compressive Identification of Active OFDM Subcarriers in Presence of Timing Offset
Abstract
In this paper we study the problem of identifying active subcarriers in an OFDM signal from compressive measurements sampled at sub-Nyquist rate. The problem is of importance in Cognitive Radio systems when secondary users (SUs) are looking for available spectrum opportunities to communicate over them while sensing at Nyquist rate sampling can be costly or even impractical in case of very wide bandwidth. We first study the effect of timing offset and derive the necessary and sufficient conditions for signal recovery in the oracle-assisted case when the true active sub-carriers are assumed known. Then we propose an Orthogonal Matching Pursuit (OMP)-based joint sparse recovery method for identifying active subcarriers when the timing offset is known. Finally we extend the problem to the case of unknown timing offset and develop a joint dictionary learning and sparse approximation algorithm, where in the dictionary learning phase the timing offset is estimated and in the sparse approximation phase active subcarriers are identified. The obtained results demonstrate that active subcarrier identification can be carried out reliably, by using the developed framework.
Year
DOI
Venue
2015
10.1109/GLOCOM.2015.7417565
IEEE Global Communications Conference
Field
DocType
Volume
Matching pursuit,Subcarrier,Mathematical optimization,Sparse approximation,Algorithm,Speech recognition,Bandwidth (signal processing),Nyquist rate,Mathematics,Offset (computer science),Orthogonal frequency-division multiplexing,Cognitive radio
Journal
abs/1507.02455
ISSN
Citations 
PageRank 
2334-0983
0
0.34
References 
Authors
20
3
Name
Order
Citations
PageRank
Seyed Alireza Razavi1427.77
Mikko Valkama21567175.51
Danijela Cabric3795101.37