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arXiv 0905.4378math.STcs.ITmath.ITstat.TH
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稀疏估计的Cramer-Rao界

The Cramer-Rao Bound for Sparse Estimation

Zvika Ben-Haim, Yonina C. Eldar

摘要:

本文的目标是表征最好的可实现的性能的问题,估计一个未知的参数具有稀疏表示。具体而言,我们考虑设置中,稀疏表示的确定性参数向量是从高斯噪声损坏的测量估计,并推导出一个下界的均方误差(MSE),可实现在此设置。为此,在稀疏设置中的偏差的适当定义,并得到约束的克拉美-罗界(CRB)。这个界被证明是等于CRB的估计与知识的支撑集,几乎所有可行的参数值。因此,在无偏的情况下,我们的界与Oracle估计量的MSE相同。结合CRB是在高信噪比的最大似然技术实现的事实,我们的结果提供了一个新的解释的共同实践中使用的Oracle估计作为一个金标准,对实际的方法进行比较。

英文摘要:

The goal of this paper is to characterize the best achievable performance for the problem of estimating an unknown parameter having a sparse representation. Specifically, we consider the setting in which a sparsely representable deterministic parameter vector is to be estimated from measurements corrupted by Gaussian noise, and derive a lower bound on the mean-squared error (MSE) achievable in this setting. To this end, an appropriate definition of bias in the sparse setting is developed, and the constrained Cramer-Rao bound (CRB) is obtained. This bound is shown to equal the CRB of an estimator with knowledge of the support set, for almost all feasible parameter values. Consequently, in the unbiased case, our bound is identical to the MSE of the oracle estimator. Combined with the fact that the CRB is achieved at high signal-to-noise ratios by the maximum likelihood technique, our result provides a new interpretation for the common practice of using the oracle estimator as a gold standard against which practical approaches are compared.

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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