Title
Pilot Design for Sparse Channel Estimation in OFDM-Based Cognitive Radio Systems
Abstract
In this correspondence, sparse channel estimation is first introduced in orthogonal frequency-division multiplexing (OFDM)-based cognitive radio systems. Based on the results of spectrum sensing, the pilot design is studied by minimizing the coherence of the dictionary matrix used for sparse recovery. Then, it is formulated as an optimal column selection problem where a table is generated and the indexes of the selected columns of the table form a pilot pattern. A novel scheme using constrained cross-entropy optimization is proposed to obtain an optimized pilot pattern, where it is modeled as an independent Bernoulli random process. The updating rule for the probability of each active subcarrier selected as a pilot subcarrier is derived. A projection method is proposed so that the number of pilots during the optimization is fixed. Simulation results verify the effectiveness of the proposed scheme and show that it can achieve 11.5% improvement in spectrum efficiency with the same channel estimation performance compared with the least squares (LS) channel estimation.
Year
DOI
Venue
2014
10.1109/TVT.2013.2280655
IEEE T. Vehicular Technology
Keywords
Field
DocType
Channel estimation,Optimization,Entropy,OFDM,Sensors,Sparse matrices,Coherence
Subcarrier,Least squares,Computer science,Stochastic process,Communication channel,Electronic engineering,Spectral efficiency,Multiplexing,Orthogonal frequency-division multiplexing,Cognitive radio
Journal
Volume
Issue
ISSN
63
2
0018-9545
Citations 
PageRank 
References 
33
1.08
12
Authors
4
Name
Order
Citations
PageRank
Chenhao Qi120926.34
Guosen Yue257342.13
Lenan Wu370062.18
Arumugam Nallanathan43694237.64