OCDMA Codeword Switching Technique to Avoid Interference of Time-of-Flight LiDAR System for Autonomous Vehicles

Lee, Giyeon; Park, Jong Kang; Kim, Jong Tae

doi:10.1109/jsen.2022.3228257

Cited by 5 publications

(5 citation statements)

References 23 publications

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“…In that case, they are refracted at different angles depending on the location, making it possible to measure more locations simultaneously. Optical CDMA (OCDMA) and OOFDMA technology can eliminate mutual interference even when multiple LiDARs operate simultaneously [37]- [39], [41], [64], [70], [71]. In LiDAR sensors, the challenge of multipath or mutual interference arises when laser pulses encounter obstacles that cause reflection or scattering.…”

Section: Operating Characteristics Of Lidarsmentioning

confidence: 99%

“…The proposed LiDAR incorporates a variable FoV function that adjusts the scanning pattern and density of the point cloud to correspond to different sizes, distances, and distributions of objects. The proposed LiDAR employs multiple pulses generated by special coding techniques, rather than a single pulse, to ensure that only the pulses it emits are distinguishable, eliminating mutual interference [34], [35], [37]- [39], [71], [78]. However, coding techniques in optics can only use the presence of light, limiting them to represent only zeros and positives, unlike RF, which can represent negative numbers.…”

Section: Cycloid Scanning Lidar Using Risley Prism and Oofdmamentioning

confidence: 99%

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A Novel Cycloidal Scanning LiDAR Sensor Using Risley Prism and Optical Orthogonal Frequency-Division Multiple Access for Aerial Applications

Kim,

Ashraf,

Eom

et al. 2024

IEEE Access

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This study proposes a novel light detection and ranging (LiDAR) sensor. The sensor integrates a variable field-of-view (FoV) function by utilizing optical orthogonal frequency-division multiple access (OOFDMA) to generate laser pulse streams and a Risley prism for steering. Using this approach, the LiDAR sensor can adjust the scanning pattern and density of the point cloud to match different sizes, distances, and distributions of objects. To ensure security against external threats, the LiDAR sensor incorporates advanced encryption standards (AES) and wavelength selection techniques. Additionally, the sensor employs various methods to achieve accurate and reliable measurements while minimizing mutual interference between laser signals. This innovative sensor has the potential to enhance the reliability and accuracy of LiDAR technology in aerial applications, thus facilitating the development of more advanced urban air mobility (UAM) sensors for diverse applications. The study evaluated a prototype LiDAR sensor that utilizes a coded laser pulse stream and OOFDMA technology for distance measurement. The LiDAR sensor incorporates three laser diodes with different wavelengths and a Risley prism for steering. The experimental results demonstrate that the proposed LiDAR sensor outperforms existing sensors in terms of accuracy and precision.

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Section: Operating Characteristics Of Lidarsmentioning

confidence: 99%

Section: Cycloid Scanning Lidar Using Risley Prism and Oofdmamentioning

confidence: 99%

A Novel Cycloidal Scanning LiDAR Sensor Using Risley Prism and Optical Orthogonal Frequency-Division Multiple Access for Aerial Applications

Kim,

Ashraf,

Eom

et al. 2024

IEEE Access

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“…LiDAR systems that use a single laser pulse are subject to similar limitations, regardless of the chosen transmission method. Researchers have explored coded pulses using randomized or optical code division multiple access (OCDMA) techniques to overcome these limitations [9], [10], [11]. This method transmits a coded laser pulse stream with unique codes to distinguish each measurement location.…”

Section: B Lateral Angular Resolutionmentioning

confidence: 99%

“…This study presents a new LiDAR that utilizes optical orthogonal frequency division multiple access (OOFDMA) to generate a laser pulse stream, as illustrated in Figure 1. The proposed LiDAR employs pulse stream generated by special coding techniques, rather than a single pulse, to ensure that only the pulses it sends are distinguishable, eliminating mutual interference [9], [10], [11], [14], [15], [16], [17]. However, coding techniques in optics can only use the presence of light, limiting them to represent only zeros (''0''s) and positives (''+1''s), unlike RF which can represent negative numbers (''−1''s).…”

Section: Oofdma-based Lidar a Design Conceptmentioning

confidence: 99%

Coded Pulse Stream LiDAR Based on Optical Orthogonal Frequency-Division Multiple Access

Kim,

Ashraf,

Eom

et al. 2023

IEEE Access

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In future mobility, robust obstacle detection is imperative for autonomous vehicles, fostering a reliance on vision-based data and the emergence of light detection and ranging (LiDAR) as a pivotal sensor. Despite challenges of cost and novelty, LiDAR's unique capabilities find favor among automakers, except Tesla. Offering 3D imaging with superior resolution than radar, LiDAR holds potential significance as a perception sensor for safe and efficient transportation. Its 3D distance measurement using laser pulses and waveform analysis is vital for obstacle detection in autonomous vehicles. Techniques like scanning and flash LiDAR optimize point cloud acquisition, albeit with challenges in balancing resolution and frame rates. Because LiDAR measures the distance to an object using the time-of-flight, the idle listening time required to detect reflected waves increases in proportion to the maximum distance. Both, lateral angular resolution and frame rates are dependent on this idle listening time. Lateral angular resolution impacts LiDAR's ability to detect objects. This study proposes an optical orthogonal frequency-division multiple access (OFDMA) LiDAR with a coded pulse technique to enhance the detection accuracy of objects. Simulation results demonstrate that the proposed OFDMA LiDAR overcoming false positives and mutual interference through pulse stream LiDARs and strategic approaches is crucial in LiDAR's integration into future mobility systems. INDEX TERMSAutonomous vehicles, LiDAR, optical communication, optical OFDMA, time-of-flight, discrete Hartley transform.

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“…The results show the optimized resource utilization by FPGA after generating RTL in system design. Utilization of the lookup table (LUT) and the flip flop is nearly equal in all the edge detection [26], [27]. DSP(digital signal processing) uses is much more in edge detection using Gaussian filter and very less in median filter edge detection and moderate in bi-lateral filter edge detection [28], [29].…”

Section: ) Resource Utilizationmentioning

confidence: 99%

FPGA based object parameter detection for Embedded Vision Application

Mo,

Singh

2023

IJCDS

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Real-time image/video processing contains complex algorithms, and the number of computation operations such as a number of additions and the number of multiplications, which are solved by CPU, results decrease in processing speed and consume more power. On the other hand, FPGA has high processing speed and low power consumption and it also has the capability to work with CPU. Hence, sharing the load and performing complex tasks, results increase the system performance. In this work, there is the development of IPs for single object detection and canny edge detection using different filters. These IPs can be used in FPGA for real-time image processing. The tool which is used is Vivado HLS, to generate the hardware accelerator and the library which is used is the xfOpenCV library. Both are developed by Xilinx. XfOpenCV library is the optimized version of OpenCV means to reduce the complexity of an algorithm for fast performance. Single object detection detects the object in real-time by using FPGA based system and xfOpenCV APIs. Similarly, edge detection using a different filter shows the effect of filters, which means removing noise in the image and making it smooth, for edge detection. Smoothing image also reduces the number of computations (Addition and Multiplication). Resource utilized by the generated IPs is very less which makes the system less heavy and more reliable.

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OCDMA Codeword Switching Technique to Avoid Interference of Time-of-Flight LiDAR System for Autonomous Vehicles

Cited by 5 publications

References 23 publications

A Novel Cycloidal Scanning LiDAR Sensor Using Risley Prism and Optical Orthogonal Frequency-Division Multiple Access for Aerial Applications

A Novel Cycloidal Scanning LiDAR Sensor Using Risley Prism and Optical Orthogonal Frequency-Division Multiple Access for Aerial Applications

Coded Pulse Stream LiDAR Based on Optical Orthogonal Frequency-Division Multiple Access

FPGA based object parameter detection for Embedded Vision Application

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