arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1504.01628cs.ITcs.NImath.IT
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基于随机矩阵理论的最快特征值频谱感知

Quickest Eigenvalue-Based Spectrum Sensing using Random Matrix Theory

Martijn Arts, Andreas Bollig, Rudolf Mathar

摘要:

我们调查的频谱感知应用的样本协方差矩阵的特征值的基础上的最快检测的潜力。考虑了加性高斯白噪声(AWGN)环境下,主用户(PU)和次用户(SU)分别为$1$和$K$的简单相移键控(PSK)模型.在$\mathcal{H}_0$(仅噪声)和$\mathcal{H}_1$(信号+噪声)这两种检测假设下,样本协方差矩阵的特征值遵循Wishart分布。对于$K = 2$ SU的情况下,我们推导出的概率密度函数(PDF)的最大-最小特征值(MME)检测器下$\mathcal{H}_1$的解析公式。利用$\mathcal{H}_0$下的文献结果,我们研究了两种检测方案。首先,我们根据分析结果计算MME块检测器的接收机操作特性(ROC)。其次,我们介绍了两种基于特征值的最快检测算法:累积和(Cumulative sum,Cumulative sum)算法,当PU信号的信噪比(SNR)是已知的和使用广义似然比的算法,在SNR是未知的情况下。给出了该算法的平均虚警时间$τ_\text{fa}$和平均检测时间$τ_\text{d}$的界。数值模拟说明了块检测方案的最快检测方法的潜在优势。

英文摘要:

We investigate the potential of quickest detection based on the eigenvalues of the sample covariance matrix for spectrum sensing applications. A simple phase shift keying (PSK) model with additive white Gaussian noise (AWGN), with $1$ primary user (PU) and $K$ secondary users (SUs) is considered. Under both detection hypotheses $\mathcal{H}_0$ (noise only) and $\mathcal{H}_1$ (signal + noise) the eigenvalues of the sample covariance matrix follow Wishart distributions. For the case of $K = 2$ SUs, we derive an analytical formulation of the probability density function (PDF) of the maximum-minimum eigenvalue (MME) detector under $\mathcal{H}_1$. Utilizing results from the literature under $\mathcal{H}_0$, we investigate two detection schemes. First, we calculate the receiver operator characteristic (ROC) for MME block detector based on analytical results. Second, we introduce two eigenvalue-based quickest detection algorithms: a cumulative sum (CUSUM) algorithm, when the signal-to-noise ratio (SNR) of the PU signal is known and an algorithm using the generalized likelihood ratio, in case the SNR is unknown. Bounds on the mean time to false-alarm $τ_\text{fa}$ and the mean time to detection $τ_\text{d}$ are given for the CUSUM algorithm. Numerical simulations illustrate the potential advantages of the quickest detection approach over the block detection scheme.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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