Optimization algorithm of periodical cooperative spectrum sensing in cognitive radio

• Published in: International journal of communication systems Vol. 27; no. 5; pp. 705 - 720
• Main Authors: Liu, Xin, Tan, Xuezhi
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.05.2014; Wiley Subscription Services, Inc
• Subjects: Algorithms; Channels; Cognitive radio; cooperative spectrum sensing; Detection; energy detection; Optimization; Plutonium; Searching; Wideband
• ISSN: 1074-5351; 1099-1131
• DOI: 10.1002/dac.2377

SUMMARYTo decrease the interference to the primary user (PU) and improve the detected performance of cognitive radio (CR), a single‐band sensing scheme wherein the CR periodically senses the PU by cooperative spectrum sensing is proposed in this paper. In this scheme, CR first senses and then transmits during each period, and after the presence of the PU is detected, CR has to vacate to search another idle channel. The joint optimization algorithm based on the double optimization is proposed to optimize the periodical cooperative spectrum sensing scheme. The maximal throughput and minimal search time can be respectively obtained through the joint optimization of the local sensing time and the number of the cooperative CRs. We also extend this scheme to the periodical wideband cooperative spectrum sensing, and the joint optimization algorithm of the numbers of the sensing time slots and cooperative CRs is also proposed to obtain the maximal throughput of CR. The simulation shows that the proposed algorithm has lower computational quantity, and compared with the previous algorithms, when SNR = 5 dB, the throughput and search time of the proposed algorithm can respectively improve 0.3 kB and decrease 0.4 s. The simulation also indicates that the wideband cooperative spectrum sensing can achieve higher throughput than the single‐band cooperative spectrum sensing. Copyright © 2012 John Wiley & Sons, Ltd. Cognitive radio (CR) performs spectrum sensing periodically as shown in Figure 1, and the communication time of CR in channel a is divided into a couple of sensing periods during which CR firstly detect the presence of the primary user (PU) in channel a. If the PU is absent, CR is able to transmit data during the following time of this period; otherwise, CR needs to vacate and start to search. When CR finds idle channel b, it should switch to the channel for transmission.