On the Cooperative LO Leakage Detection with Power Supply Control for Hidden Eavesdroppers

Detecting local oscillator (LO) leakage for hidden radio frequency (RF) devices is now the primary approach to countermeasure eavesdropping threats in wireless security. However, due to the low power and fast decay of LO leakage, the detection range and robustness of this approach are still limited. To overcome the above difficulties and improve the detection performance, this study presents a cooperative detection scheme for LO leakage utilizing multiple receivers simultaneously. Based on the defined power supply signal waveform for the device under test (DUT), the determination quantity for LO leakage in the spectrum is derived, and the detection performance indicators are derived based on the statistical analysis and assumed signal model. Considering the received signal quantity difference in multiple receivers, a simple yet robust performance optimization procedure is proposed to select a minimum number of receivers for best performance. Extensive numerical experiments are carried out to validate the correctness of the proposed methods and demonstrate the performance enhancement in LO leakage.