Adaptive double threshold energy detection based on Markov model for cognitive radio

Abstract

The rapid development in the area of cognitive radio technology leads the society to higher standards of spectrum sensing performance, particularly in low signal-to-noise ratio (SNR) environment. This article proposes an adaptive double-threshold energy sensing method based on Markov model (ADEMM). When using the double-threshold energy sensing method, the modified Markov model that accounts for the time varying characteristic of the channel occupancy was presented to resolve the ‘confused’ channel state. Furthermore, in order to overcome the effect of noise uncertainty, the findings of this article introduce an adaptive double-threshold spectrum sensing method that adjusts its thresholds according to the achievable maximal detection probability. Numerical simulations show that the proposed ADEMM achieves better detection performance than the conventional double-threshold energy sensing schemes, especially in very low SNR region.

A Two-Step Cooperative Energy Detection Algorithm Robust to Noise Uncertainty

“…In addition, we assume that the useful signal exists throughout the detection processing. When becomes large enough, according to the central limit theorem, the detection statistic of energy detection for the -th detection node approximately obeys a normal distribution [18]:…”

“…Step of Cooperative Algorithm. The double threshold has been applied to improve the detection performance [18]. In this paper, two thresholds and ℎ of the -th detection node are calculated by (7) with minimum noise variance and maximum noise variance respectively…”

“…In order to reduce the computational complexity and system overhead, the decision result 0 or 1 of the first cooperation can be directly used as the final decision result, which means the second step of cooperative would not be triggered until the decision result is uncertain. In this case, the false alarm probability and detection probability of first cooperation step are described by (17) and (18), respectively.…”

Retraction: Adaptive double threshold energy detection based on Markov model for cognitive radio

“…Following publication of this article [1], concerns were raised regarding substantial overlap in the equations and data with work reported in a previous publication by some of the same authors [2], which was not cited or discussed.…”

“…Following evaluation by a member of the Editorial Board, it was determined that the approach and majority of the analyses in the PLOS ONE article are reported in [2]. Additionally, it was noted that there is some text overlap in the “Markov model based on time-varying parameters for spectrum occupancies” section compared with a number of previously published works by other authors [3–5]; that a number of equations as well as Algorithm 1 are equivalent or similar to those reported in [3]; and that the unique contribution of this work [1] in the context of existing literature is not accurately and clearly identified.…”