Coexistent Evaluation on the Effects of Radar PRF and 5G Symbol Based Scheduling

The increasing demand for spectrum necessitates the shared use of frequency bands between commercial wireless systems and incumbent radar operations. The 3.5 GHz Citizens Broadband Radio Service (CBRS) band in the United States is a prime example where 5G New Radio (NR) deployments must coexist with federal radar systems. This paper explores the relationship between pulsed sensor interference, particularly its Pulse Repetition Frequency (PRF), and the resulting effects on 5G downlink throughput. We present a comprehensive research approach combining a simulation framework utilizing open-source 5G software stacks and custom radar modeling in MATLAB, validated by over-the-air (OTA) experiments with a commercial UE and Software Defined Radios (SDRs). Our findings demonstrate that 5G and radar coexistence is achievable under certain conditions, and critically, not all radar interference scenarios result in complete blockage of 5G communications. The simulations reveal that for low radar PRFs (below 3 kHz) and under 15% duty cycle, strategic adjustment of 5G symbol-based scheduling can lead to notable improvements in downlink throughput. Furthermore, the results from our real-world OTA testing show good alignment with the simulation outcomes, confirming the viability of our modeling approach. This work identifies specific sensor PRF ranges that are more conducive to cellular coexistence and highlights the potential for preserving 5G performance under high duty cycle conditions by adapting TTI boundaries and symbol allocations.