Detection of Gauss-Markov Random Fields with Nearest-Neighbor Dependency

Abstract—The problem of hypothesis testing against independence for a Gauss–Markov random field (GMRF) is analyzed. Assuming an acyclic dependency graph, an expression for the log-likelihood ratio of detection is derived. Assuming random placement of nodes over a large region according to the Poisson or uniform distribution and nearest-neighbor dependency graph, the error exponent of the Neyman–Pearson detector is derived using large-deviations theory. The error exponent is expressed as a dependency-graph functional and the limit is evaluated through a special law of large numbers for stabilizing graph functionals. The exponent is analyzed for different values of the variance ratio and correlation. It is found that a more correlated GMRF has a higher exponent at low values of the variance ratio whereas the situation is reversed at high values of the variance ratio.

• Type: Journal
• Year: 2007
• Where: CORR
• Authors: Animashree Anandkumar, Lang Tong, Ananthram Swami
• Keywords: CORR 2007, Dependency Graph, Education, Error Exponent, Variance Ratio