Direct Time-of-Flight (d-ToF) Pulsed LiDAR Sensor With Simultaneous Noise and Interference Suppression

This article presents a direct time-of-flight (d-ToF) pulsed light detection and ranging (LiDAR) sensor with interference suppression and a linear-mode receiver implemented using discrete components. The sensor achieves 0.3 degrees (horizontal) x 1 degrees (vertical) angular resolution with 60 (H) \times 8 (V) pixels using 2-D mechanical scanning, covering 18 degrees (H) \times 8 degrees (V) field of view (FoV). Measurements, up to the range of 4.5 m using 1-D line scanning and a 100-kHz laser source, show a frame rate of 16 frames/s and a precision of 0.2%. Furthermore, a novel coding mechanism is introduced that effectively suppresses interference signals, while adding minimal complexity to the regular time-correlated single-photon counting (TCSPC) processing and without compromising the sensor specifications, such as the maximum range and frame rate. The proposed technique can effectively suppress even very strong interference signals. In general, the proposed technique can provide up to 2(N) times interference suppression using N-bit pseudorandom codes. The measurement results show an interference suppression of 15.29 dB using 3-bit pseudorandom coding, which follows the claimed 2(N) rule with a good approximation.