Reliable Sub-Nyquist Spectrum Sensing via Conformal Risk Control

TL;DR

This paper introduces a conformal risk control method for sub-Nyquist spectrum sensing that guarantees false negative rate constraints regardless of data size, improving reliability in wireless spectrum detection.

Contribution

It applies conformal risk control to spectrum sensing, providing formal FNR guarantees and enhancing detection performance over existing methods.

Findings

CRC guarantees user-specified FNR constraints

CRC achieves competitive true negative rate

Experimental validation confirms theoretical guarantees

Abstract

Detecting occupied subbands is a key task for wireless applications such as unlicensed spectrum access. Recently, detection methods were proposed that extract per-subband features from sub-Nyquist baseband samples and then apply thresholding mechanisms based on held-out data. Such existing solutions can only provide guarantees in terms of false negative rate (FNR) in the asymptotic regime of large held-out data sets. In contrast, this work proposes a threshold mechanism-based conformal risk control (CRC), a method recently introduced in statistics. The proposed CRC-based thresholding technique formally meets user-specified FNR constraints, irrespective of the size of the held-out data set. By applying the proposed CRC-based framework to both reconstruction-based and classification-based sub-Nyquist spectrum sensing techniques, it is verified via experimental results that CRC not only provides theoretical guarantees on the FNR but also offers competitive true negative rate (TNR) performance.