Analysis and Compensation of Phase Noise in FMCW LiDAR Sensors

Light detection and ranging (LiDAR) sensors bring remarkable features to the automotive industry, enabling the development of autonomous vehicles. More concretely, frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR) sensors offer several advantages over their time-of-flight (ToF) counterparts in terms of maximum achievable distance, interference immunity, and velocity detection. Nonetheless, FMCW LiDAR systems are inevitably affected by phase noise, limiting the sensor performance. One evident solution consists in using narrow linewidth lasers, at the expense of overall sensor cost. Therefore, in this work, a thorough analysis of the phase noise is conducted for FMCW LiDAR sensors. Moreover, a novel and low-complex phase noise compensation algorithm based on pre-estimation and feedforward correction (PNC-PEFC) is proposed. The PNC-PEFC algorithm is extensively evaluated in an experimental setup under different target distances and additive white Gaussian noise (AWGN) conditions. The experimental results show excellent performance when applying the proposed PNC-PEFC algorithm, proving its robustness across all evaluated conditions.