Impact of Uplink Traffic on 5G-Based Passive Radar

Several pioneering works have presented experimental results of 5G-based passive radars. In those works, the illumination source is a signal transmitted by the 5G base station (simulated and real-life). Therefore the uplink (UL) signal (transmitted from user equipment to the base station with a time division duplex (TDD)) was considered a source of interference and was cut to achieve successful target detection. This work presents an in-depth analysis of the impact of the uplink signal on the performance of the 5G-based passive radar. The study shows that in most scenarios, the implications of uplink traffic are insignificant, which is a valuable conclusion considering the real-time implementation of the 5G-based passive radar. It is shown that skipping the step of uplink cancelation in the TDD 5G network-based passive radar results in significant computational complexity reduction. The simulations were carried out under various conditions, including the different instantaneous amounts of resources allocated in both directions of wireless network traffic and the distance from the radar receiver to the base station and the user equipment. The experimental validation (using real-life 5G signals) of the conducted research proved the simulation results.