Discussion of the operating range of frequency modulated radars in the presence of interference

Abstract

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.

Interference of chirp sequence radars by OFDM radars at 77 GHz

“…This is because the window function applied in signal processing takes a different influence on the power of each interfering subcarrier, depending on the carrier's frequency. This is a similar effect as it was reported for CW radar interference in [4]. For the modulation order analysis, PSK modulations of k = 2, 4, 8, 16 are analyzed.…”

“…Using equation (17) of [4], the maximum power of an interfering CW radar in the rangeDoppler spectrum yields…”

“…Similar interference effects can be shown for chirp sequence radars, cf. [4]. Multiple countermeasures already exist to this kind of interferences, like time domain signal repair [5], digital beamforming [6], [7], or frequency hopping [8].…”

Automotive radar interference mitigation using a sparse sampling approach

“…For the very common FMCW (frequency modulated continuous wave) radars, a high chance for interference has been predicted if the sensors have different ramp slopes [1]. Although the occurrence of ghost targets is very unlikely [1], [2], interferences lead to a wide-band increase of the noise floor in the baseband signals, and therefore can severely decrease the detection capability of the sensors [3]. Even if interferences are received only through the side-lobes of a sensor, their effect is not negligible [4].…”

Simulative Prediction of the Interference Potential Between Radars in Common Road Scenarios

“…However, he mentioned that interference between radars should already be taken into account during the process of system design. Subsequent to Hischke's publication, several works dealt with the topic of radar interference [3]- [11]. The publications [7]- [9], [11] can be seen in the context of an European research project, which was started in 2010 to enhance the communities' knowledge about interference between automotive radars (MOSARIM project).…”