Distributed Detection Fusion via Monte Carlo Importance Sampling

TL;DR

This paper introduces a Monte Carlo importance sampling framework for distributed detection fusion in large sensor networks with dependent observations, providing efficient algorithms and analytical solutions for specific fusion rules.

Contribution

It proposes a novel Monte Carlo-based method for optimizing sensor decision rules in high-dimensional dependent observation scenarios, reducing computational complexity and deriving analytical solutions for certain fusion rules.

Findings

The new algorithm has complexity $O(LN)$, significantly lower than previous methods.

Analytical solutions are derived for AND and OR fusion rules.

Numerical examples confirm the effectiveness of the proposed approach.

Abstract

Distributed detection fusion with high-dimension conditionally dependent observations is known to be a challenging problem. When a fusion rule is fixed, this paper attempts to make progress on this problem for the large sensor networks by proposing a new Monte Carlo framework. Through the Monte Carlo importance sampling, we derive a necessary condition for optimal sensor decision rules in the sense of minimizing the approximated Bayesian cost function. Then, a Gauss-Seidel/person-by-person optimization algorithm can be obtained to search the optimal sensor decision rules. It is proved that the discretized algorithm is finitely convergent. The complexity of the new algorithm is $O(LN)$ compared with $O(LN^L)$ of the previous algorithm where $L$ is the number of sensors and $N$ is a constant. Thus, the proposed methods allows us to design the large sensor networks with general high-dimension dependent observations. Furthermore, an interesting result is that, for the fixed AND or OR fusion rules, we can analytically derive the optimal solution in the sense of minimizing the approximated Bayesian cost function. In general, the solution of the Gauss-Seidel algorithm is only local optimal. However, in the new framework, we can prove that the solution of Gauss-Seidel algorithm is same as the analytically optimal solution in the case of the AND or OR fusion rule. The typical examples with dependent observations and large number of sensors are examined under this new framework. The results of numerical examples demonstrate the effectiveness of the new algorithm.