tailieunhanh - Báo cáo toán học: " Optimization of cooperative spectrum sensing with sensing user selection in cognitive radio networks"

Tuyển tập các báo cáo nghiên cứu khoa học ngành toán học được đăng trên tạp chí toán học quốc tế đề tài: Optimization of cooperative spectrum sensing with sensing user selection in cognitive radio networks | Yu et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 208 http content 2011 1 208 o EURASIP Journal on Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Optimization of cooperative spectrum sensing with sensing user selection in cognitive radio networks Huogen Yu Wanbin Tang and Shaoqian Li Abstract Cooperative spectrum sensing CSS can improve the spectrum sensing performance by introducing spatial diversity in cognitive radio networks CRNs . However such cooperation also introduces the delay for reporting sensing data. Conventional cooperation scheme assumes that the cooperative secondary users SUs report their local sensing data to the fusion center sequentially. This causes the reporting delay to increase with the number of the cooperative SUs and ultimately affects the performance of CSS. In this article we consider the reporting delay and formulate the optimization problem of CSS with sensing user selection to maximize the average throughput of the CRN in both the additive white Gaussian noise AWGN environment and the Rayleigh fading environment. It is shown that selecting all the SUs within the CRN to cooperate might not achieve the maximal average throughput. In particular for the AWGN environment the sensing user selection scheme is equivalent to selecting the optimal number of cooperative SUs due to all the SUs having the same instantaneous detection signal-to-noise ratio SNR . For the Rayleigh fading environment the maximal average throughput is achieved by selecting a certain number of cooperative SUs with the highest instantaneous detection SNRs to cooperate. Finally computer simulations are presented to demonstrate that the average throughput of the CRN can be maximized through the optimization. Keywords cooperative spectrum sensing cognitive radio reporting delay optimization sensing user selection 1 Introduction Cognitive radio CR technology has recently been identified