Nonparametric Decentralized Detection and Sparse Sensor Selection via Multi-Sensor Online Kernel Scalar Quantization

TL;DR

This paper introduces an online kernel-based method for signal classification in wireless sensor networks, optimizing sensor quantization and selection to enhance accuracy and resource efficiency.

Contribution

It proposes a novel multi-sensor online kernel scalar quantization (MSOKSQ) algorithm with theoretical analysis and demonstrates its effectiveness in sensor selection and classification accuracy.

Findings

Improves classification accuracy through joint quantizer and sensor selection optimization.

Provides convergence analysis linking online and batch learning.

Shows robustness to sensor reduction in numerical experiments.

Abstract

Signal classification problems arise in a wide variety of applications, and their demand is only expected to grow. In this paper, we focus on the wireless sensor network signal classification setting, where each sensor forwards quantized signals to a fusion center to be classified. Our primary goal is to train a decision function and quantizers across the sensors to maximize the classification performance in an online manner. Moreover, we are interested in sparse sensor selection using a marginalized weighted kernel approach to improve network resource efficiency by disabling less reliable sensors with minimal effect on classification performance.To achieve our goals, we develop a multi-sensor online kernel scalar quantization (MSOKSQ) learning strategy that operates on the sensor outputs at the fusion center. Our theoretical analysis reveals how the proposed algorithm affects the quantizers across the sensors. Additionally, we provide a convergence analysis of our online learning approach by studying its relationship to batch learning. We conduct numerical studies under different classification and sensor network settings which demonstrate the accuracy gains from optimizing different components of MSOKSQ and robustness to reduction in the number of sensors selected.