Multi-Path Interference Challenges and Suggested Solution for Correlation-Assisted Direct Time-of-Flight

The correlation-assisted direct time-of-flight (CA-dToF) pixel offers a promising approach for low-power consumption, ambient light robustness, and high-resolution depth sensing. However, as with other time-of-flight systems based on global phase estimation, its reliability is compromised by multi-path interference (MPI) of the emitted light, leading to depth estimation errors. In this work, the impact of MPI on CA-dToF pixel performance is systematically analyzed. Furthermore, a multi-frequency modulation algorithm is proposed to mitigate MPI effects. The proposed method improves depth accuracy and enhances the overall reliability of the CA-dToF system.