Impact on radar probability of detection due to interference from 4G communication signals

In this paper, we quantify the degradation of probability of detection in radars due to interference from wideband communication signals. Two typical radar systems in L-band and S-band given in ITU-R Recommendations are simulated, and Long-term Evolution (LTE) signals are used as the interference source. The focus of this paper is to analyse how interference manifests in different radar signal processing stages which include pulse compression, Doppler processing, and constant false alarm rate (CFAR) detection, and to finally quantify the detection losses of the radars. Linear and non-linear chirp radar waveforms are used in the analysis. On average, 1.3 - 1.4 dB loss at detection probability of 0.5 is observed for the two radar systems considered at an interference level -6 dB below the noise floor. In the worst case, this detection loss is increased up to 4.7 dB. A Gaussian interferer is also applied, and results show that degradation in detection in the presence of LTE interference is more significant compared to the Gaussian interference.