Asymptotically optimum detection of primary user in cognitive radio networks

• Published in: IET communications Vol. 1; no. 6; pp. 1138 - 1145
• Main Authors: Taherpour, A., Norouzi, Y., Nasiri-Kenari, M., Jamshidi, A., Zeinalpour-Yazdi, Z.
• Format: Journal Article
• Language: English
• Published: Stevenage Institution of Engineering and Technology 01.12.2007; John Wiley & Sons, Inc
• Subjects: Applied sciences; Asymptotic properties; Band spectra; Bands; Cognitive radio; Detection, estimation, filtering, equalization, prediction; Error analysis; Exact sciences and technology; Frequency spectrum; Information, signal and communications theory; Monitors; Optimization; Radiocommunication specific techniques; Radiocommunications; Signal and communications theory; Signal, noise; Telecommunications; Telecommunications and information theory; Quantization error; Frequency spectrum; Optimal detection; Signal detection; Sequential detection; Radio communication; Software radio
• DOI: 10.1049/iet-com:20060645
• ISSN: 1751-8628

Traditionally, the frequency spectrum is licensed to users by government agencies in a fixed manner where the licensee has exclusive right to access the allocated band. However, with increasing demand for the spectrum and scarcity of vacant bands, a spectrum policy reform seems inevitable. Meanwhile, recent measurements suggest the possibility of sharing spectrum among different parties subject to interference-protection constraints. In order to enable access to an unused licensed spectrum, a secondary user has to monitor licensed bands and opportunistically transmit whenever no primary signal is detected. Spectrum-sharing between a primary licensee and a group of secondary users has been studied. The structure of an asymptotically optimum detector based on the measurements of all secondary users is derived and the effect of the quantisation error in such a system is evaluated. Also, it is shown that by using the proposed detector in a sequential detection structure, it is possible to shorten the decision time needed by the detector. The results show the superiority of the proposed detector to other schemes.