Automotive Frequency Modulated Continuous Wave Radar Interference Reduction Using Per-Vehicle Chirp Sequences

Abstract

Recently, many automobiles adopt radar sensors to support advanced driver assistance system (ADAS) functions. As the number of vehicles with radar systems increases the probability of radar signal interference and the accompanying ghost target problems become serious. In this paper, we propose a novel algorithm where we deploy per-vehicle chirp sequence in a frequency modulated continuous wave (FMCW) radar to mitigate the vehicle-to-vehicle radar interference. We devise a chirp sequence set so that the slope of each vehicle’s chirp sequence does not overlap within the set. By assigning one of the chirp sequences to each vehicle, we mitigate the interference from the radar signals transmitted by the neighboring vehicles. We confirm the performance of the proposed method stochastically by computer simulation. The simulation results show that the detection and false alarm performance is improved significantly by the proposed method.

Generating and Detecting Solvable Chaos at Radio Frequencies with Consideration to Multi-User Ranging

“…User "A" transmits a waveform to measure distance, however, user "A" also receives transmissions generated by other users ("B" and "C"). As discussed earlier, FMCW schemes require new slopes to form a chirp sequence [29] with randomization in order to minimize mutual interference [15]. Here, we show that solvable chaos-based ranging efficiently generates unique signals that may be optimally detected and mitigate against interference/jamming.…”

“…Ultimately, this problem occurs because many systems must share a limited natural resource: the electromagnetic spectrum. Thus, the need for user-specific waveforms is motivated by the combined effects from both mutual interference issues due to multiple sensors and multitarget returns problems [15].…”

“…As interference increases with multiple users, the reliability of assisted driving systems can degrade [9]. These issues motivate the use of specialized, less-predictable waveforms [10][11][12][13][14][15]. Thus, we propose the use of solvable chaos as it exhibits noise-like properties and may be optimally detected using a simple matched filter [16].…”

“…This issue is common in many realistic scenarios involving vehicles [6][7][8][9], mobile robots [23,24], and drones [25][26][27]. One successful mitigation technique requires user-specific [15], entropic (noisy) waveforms for spread spectrum techniques such as those used in sonar [10,11] and radar [12][13][14]28] systems. Throughout this section, we provide a brief description of the limitations of FMCW ranging in order to motivate the use of user-specific, noisy waveforms generated from a solvable chaotic source.…”

An Elaborated Signal Model for Simultaneous Range and Vector Velocity Estimation in FMCW Radar

“…A significant disadvantage of the method is the appearance of false radar targets (false alarms) [ 12 ]. One of the ways to combat false targets is the use of a segmented structure of a sounding radio signal with variable modulation parameters: chirp duration, frequency deviation and initial generation frequency [ 13 , 14 , 15 , 16 , 17 ]. The creation of a segmented structure of the sounding radio signal can significantly reduce the likelihood of false targets.…”