DocumentCode :
1940753
Title :
Spectrum Sensing in Cognitive Radios Based on Multiple Cyclic Frequencies
Author :
Lunden, Jarmo ; Koivunen, Visa ; Huttunen, Anu ; Poor, H.Vincent
Author_Institution :
SMARAD CoE, Signal Processing Laboratory, Helsinki Univ. of Technology, Finland, Email: jrlunden@wooster.hut.fi
fYear :
2007
fDate :
1-3 Aug. 2007
Firstpage :
37
Lastpage :
43
Abstract :
Cognitive radios sense the radio spectrum in order to find unused frequency bands and use them in an agile manner. Transmission by the primary user must be detected reliably even in the low signal-to-noise ratio (SNR) regime and in the face of shadowing and fading. Communication signals are typically cyclostationary, and have many periodic statistical properties related to the symbol rate, the coding and modulation schemes as well as the guard periods, for example. These properties can be exploited in designing a detector, and for distinguishing between the primary and secondary users´ signals. In this paper, a generalized likelihood ratio test (GLRT) for detecting the presence of cyclostationarity using multiple cyclic frequencies is proposed. Distributed decision making is employed by combining the quantized local test statistics from many secondary users. User cooperation allows for mitigating the effects of shadowing and provides a larger footprint for the cognitive radio system. Simulation examples demonstrate the resulting performance gains in the low SNR regime and the benefits of cooperative detection.
Keywords :
Cognitive radio; Detectors; Face detection; Fading; Frequency; Modulation coding; Shadow mapping; Signal design; Signal to noise ratio; Testing;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Cognitive Radio Oriented Wireless Networks and Communications, 2007. CrownCom 2007. 2nd International Conference on
Conference_Location :
Orlando, FL, USA
Print_ISBN :
978-1-4244-0814-6
Electronic_ISBN :
978-1-4244-0815-3
Type :
conf
DOI :
10.1109/CROWNCOM.2007.4549769
Filename :
4549769
Link To Document :
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