DocumentCode :
3071584
Title :
Spectral Shaping for Adjacent Band Interference Suppression in Cognitive Radio Systems
Author :
Joshi, Deepak R. ; Popescu, Dimitrie C. ; Dobre, Octavia A. ; Baddour, Kareem E.
Author_Institution :
Dept. of Electr. & Comput. Eng., Old Dominion Univ., Norfolk, VA, USA
fYear :
2011
fDate :
5-9 Dec. 2011
Firstpage :
1
Lastpage :
5
Abstract :
Cognitive radio (CR) technology represents a promising solution for solving the problem of spectrum scarcity and underutilization in wireless communications. While orthogonal frequency division multiplexing (OFDM) is regarded as a suitable technology for the CR physical layer, it can suffer from out-of-band radiation, which hinders its spectrum sharing capabilities. In this paper we consider a turbo-coded OFDM based CR system, and propose three methods for shaping the spectrum of the CR signal to reduce interference affecting primary users (PUs) that operate in adjacent bands. The proposed methods use multiple choice sequences (MCS) generated at the bit level by employing different pseudo random bit sequences, by using bit interleavers with different depths, or by a combination of both, respectively. In order to reduce interference to adjacent bands, the sequence with the best spectral shape is transmitted along with its index. Performance of the proposed methods is illustrated with numerical results obtained from simulations, and the trade off between a better spectral shape and the reduction in the spectral efficiency of the systems is discussed.
Keywords :
OFDM modulation; cognitive radio; interference suppression; interleaved codes; radio spectrum management; radiofrequency interference; random sequences; turbo codes; CR physical layer; CR signal; adjacent band interference suppression; bit interleaver; cognitive radio system; interference reduction; orthogonal frequency division multiplexing; pseudo random bit sequence; spectral efficiency; spectral shaping; spectrum scarcity; spectrum sharing capability; turbo-coded OFDM based CR system; wireless communication; Cognitive radio; Decoding; Indexes; Interference; OFDM; Transmitters; Turbo codes;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Global Telecommunications Conference (GLOBECOM 2011), 2011 IEEE
Conference_Location :
Houston, TX, USA
ISSN :
1930-529X
Print_ISBN :
978-1-4244-9266-4
Electronic_ISBN :
1930-529X
Type :
conf
DOI :
10.1109/GLOCOM.2011.6133694
Filename :
6133694
Link To Document :
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