The Locally Most Powerful Test for Multiantenna Spectrum Sensing With Uncalibrated Receivers
Spectrum sensing is a key component of the Cognitive Radio (CR) paradigm. Among CR detectors, multi-antenna detectors are gaining popularity since they improve the detection performance and are robust to noise uncertainties. Traditional approaches to multi-antenna spectrum sensing are based on the Generalized Likelihood Ratio Test (GLRT) or other heuristic detectors, which are not optimal in the Neyman-Pearson sense. In this paper, the authors derive the Locally Most Powerful Invariant Test (LMPIT), which is the optimal detector, among those preserving the problem invariances, in the low SNR regime. In particular, they apply Wijsman's theorem, which provides one an alternative way to derive the ratio of the distributions of the maximal invariant statistic.