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arXiv 1605.05910stat.MEstat.AP
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复值向量时间序列正确性的频域检验

A Frequency Domain Test for Propriety of Complex-Valued Vector Time Series

Swati Chandna, Andrew T. Walden

摘要:

本文提出了一种频域方法来检验复值向量时间序列是适当的假设,即,用于测试矢量时间序列是否与其复共轭不相关。如果该假设被拒绝,则将识别引起拒绝的频带,并且该频带可能有用地与物理过程的已知属性相关。该测试需要相关的光谱矩阵,该矩阵可以通过使用例如$K$锥度的多锥度方法来估计。检验统计量的标准渐近分布没有用,因为它们需要$K \rightarrow \infty,$,但是随着$K$增加,分辨率带宽也增加,这会导致光谱模糊。在许多分析$K$是必须保持小,因此我们的努力是针对小$K.$的假设检验的实用和准确的方法。我们的广义似然比统计量结合精确的累积量匹配给出了非常准确的拒绝百分比,优于其他方法。我们还证明,统计检验的基础上,是由典型的相干性所产生的从我们的复值向量时间序列。我们的方法证明了在拉布拉多海不同深度收集的海流数据。总的来说,这项工作扩展的结果适当测试复值向量的复值向量时间序列设置。

英文摘要:

This paper proposes a frequency domain approach to test the hypothesis that a complex-valued vector time series is proper, i.e., for testing whether the vector time series is uncorrelated with its complex conjugate. If the hypothesis is rejected, frequency bands causing the rejection will be identified and might usefully be related to known properties of the physical processes. The test needs the associated spectral matrix which can be estimated by multitaper methods using, say, $K$ tapers. Standard asymptotic distributions for the test statistic are of no use since they would require $K \rightarrow \infty,$ but, as $K$ increases so does resolution bandwidth which causes spectral blurring. In many analyses $K$ is necessarily kept small, and hence our efforts are directed at practical and accurate methodology for hypothesis testing for small $K.$ Our generalized likelihood ratio statistic combined with exact cumulant matching gives very accurate rejection percentages and outperforms other methods. We also prove that the statistic on which the test is based is comprised of canonical coherencies arising from our complex-valued vector time series.Our methodology is demonstrated on ocean current data collected at different depths in the Labrador Sea. Overall this work extends results on propriety testing for complex-valued vectors to the complex-valued vector time series setting.

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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