ETD

• CFAR detection
• dynamic clutter
• generalized ambiguity function
• inter-pulse phase noise
• intra-pulse phase noise
• ISAC
• oscillator phase noise
• range-Doppler processing
• static clutter

This thesis investigates the impact of oscillator phase noise on the performance of an Integrated Sensing and Communication (ISAC) system operating in a cluttered radar scenario. The considered application is related to the detection of low-altitude aerial targets, such as drones or unmanned aerial vehicles, in the presence of both static and dynamic clutter. Starting from an ideal radar processing chain, a realistic phase noise model based on oscillator power spectral density specifications is introduced and incorporated into the received signal model. The analysis focuses on the effect of oscillator phase noise on matched filtering, ambiguity functions, range-Doppler processing, and CFAR target detection. Both inter-pulse and intra-pulse phase noise effects are considered, in order to distinguish between phase variations occurring from pulse to pulse and phase fluctuations within each transmitted pulse. Two oscillator configurations are analyzed: a common oscillator shared by transmitter and receiver, and a configuration with independent transmitter and receiver oscillators. Numerical simulations are performed under nominal oscillator specifications and under artificially amplified phase noise conditions used as stress tests. The results show that, under nominal phase noise levels, the target range-Doppler response and the CFAR detection performance are only marginally affected. In both oscillator configurations, the target remains correctly localized in range and Doppler, and the detection capability is preserved. However, under severe phase noise conditions, the degradation becomes more significant, especially when independent transmitter and receiver oscillators are considered. In this case, the target peak can be reduced, with possible missed detections and false alarms.
Overall, this work shows that the considered ISAC radar scenario is robust to nominal oscillator phase noise levels, while the oscillator configuration becomes relevant under severe phase noise conditions.