Proper management of mutual interference plays an important role in the successful simultaneous operation of automotive frequency-modulated continuous-wave (FMCW) radar sensors at different vehicles. Compared to traditional interference handling concepts such as detect-and-mitigate or detect-and-avoid, the detect-and-exploit paradigm turns the originally interfering signals into signals of interest and uses them to obtain information about the environment. Following this idea, a method that implements such an interference exploitation strategy in terms of joint passive spectral sensing and localization of surrounding objects is elaborated and presented in this work. In summary, the method consists of a dedicated radar operational mode and a corresponding signal processing chain including pre-processing, beam steering-based signal component separation, maximum likelihood (ML)–inspired signal parameter estimation, and joint direction of arrival (DoA)-time difference of arrival (TDoA) based object localization. The unique advantage of the presented concept compared to over-the-air synchronization (OTAS)-based solutions is that it can also deal with interferers that change their ramp parameters over time. The applicability of the concept is both theoretically analyzed as well as practically demonstrated by means of measurements in an anechoic chamber, where the position of the interferer and an additional object in the surrounding can be determined with an accuracy of a few centimeters.

Maritime traffic has significantly increased in recent decades due to its advantageous costs, delivery rate and environmental compatibility. With the advent of the new generation of marine radars, based on the solid-state transmitter technology that calls for much longer transmitted pulses, the interference problem can become critical. Knowing the positions and the heights of the ships, the mean number of the vessels in radar range can be estimated to evaluate the effects of their mutual radar interferences. This paper aims to estimate the probability density function of the mutual distances. The truncation of the density function within a limited area related to horizon visibility leads to a simple single-parameter expression, useful to classify the ships as either randomly distributed or following a defined route. Practical results have been obtained using Automatic Identification System (AIS) data provided by the Italian Coast Guard in the Mediterranean Sea.

This paper discusses the operating range of frequency modulated (FM) radars in the presence of interference. For this purpose, radar- and path loss equations are used to draw the equipotential lines for a given signal-to-interference ratio as a function of the spatial distribution of targets and interferers in order to identify relevant scenario constellations. Further the factors influencing the gain of signal versus deterministic interference are discussed based on measurements and simulations. Finally, the influence of different kinds of interference on the spectrum of a frequency modulated continuous wave radar is shown.