In this paper, we detect illegal spectrum access behaviors in the dynamic spectrum sharing of the cognitive wireless networks, in which multiple authorized users (AUs) work in the same channel. First, we detect whether there are users occupy the channel, and if the channel is occupied, then recognize whether there is the illegal user (IU) and infer the number of AUs roughly. In the light of the thorny challenge that legal spectrum utilization behaviors and illegal spectrum access behaviors coexist probabilistically, the spectrum sensing problem is formulated as a mathematical model of ternary hypothesis test. Moreover, when multiple AUs are working at the same time, it is extremely difficult to detect IU. To tackle the problem, taking into account the various potential combinations of AUs and IU, we exploit a two-step detector and derive related detection schemes based on the generalized likelihood ratio test (GLRT), the Rao test, and the Wald test following the generalized multi-hypothesis Neyman-Pearson (GMNP) criterion respectively. Additionally, we design a cooperative spectrum sensing (CSS) scheme on the basis of the global GMNP criteria, in which the distributed detection framework composed of K{K} sensing nodes and a fusion center (FC). Finally, to verify the performance of the proposed detection scheme in a variety of parameter configurations, we provide comprehensive simulations and find that there will be at most (2N−1)({{2^{N}}-1}) detection valleys when N{N} AUs work at the same time. Compared with single-sensing node detection, the CSS scheme can significantly improve the detection performance of the proposed detection schemes, especially in the upper bound and valley of the detection performance.

中文翻译：

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多授权用户场景非法频谱接入行为下的频谱感知


在本文中，我们检测认知无线网络动态频谱共享中的非法频谱访问行为，其中多个授权用户（AU）在同一信道中工作。首先检测是否有用户占用信道，如果信道被占用，则识别是否存在非法用户（IU）并粗略推断AU的数量。针对合法频谱利用行为与非法频谱接入行为概率共存的棘手挑战，将频谱感知问题表述为三元假设检验的数学模型。而且，当多个AU同时工作时，检测IU是极其困难的。为了解决这个问题，考虑到 AU 和 IU 的各种潜在组合，我们利用两步检测器，并根据广义似然比检验 (GLRT)、Rao 检验和 Wald 检验推导出相关的检测方案。分别采用广义多假设 Neyman-Pearson (GMNP) 准则。此外，我们基于全球GMNP标准设计了一种协作频谱感知（CSS）方案，其中分布式检测框架由K{K}个感知节点和融合中心（FC）组成。最后，为了验证所提出的检测方案在各种参数配置下的性能，我们提供了全面的仿真，发现最多会有 (2N−1)({{2^{N}}-1}) 个检测谷当N{N}个AU同时工作时。与单感知节点检测相比，CSS方案可以显着提高所提出的检测方案的检测性能，特别是在检测性能的上限和谷值方面。