Special Session 07 at CSNDSP 2026

Wearable light-emitting diodes (LEDs) have recently emerged as promising transmitters for optical camera communications (OCC), enabling data transmission by being integrated into garments or accessories. In this work, we investigate the use of fabrics as optical diffusers for wearable LED transmitters in OCC systems. First, we develop an experimental testbed for angular radiation pattern characterization of textile-covered LEDs, enabling systematic measurement of horizontal emission profiles. Secondly, we derive a fabric diffuser model that analytically relates the native LED radiation pattern to the resulting garment-level emission, capturing the angular redistribution introduced by the fabric in a physically motivated framework. Thirdly, we propose a sewing pattern design methodology that supports the practical embedding of LEDs in garments while preserving optical performance and wearability. Finally, we demonstrate that flexible fabrics have the potential to be used as efficient optical diffusers in wearable OCC devices, thereby providing possibilities for developing more user-friendly and robust devices.

This paper proposes a novel method to identify visible light beacons using rolling shutter Optical Camera Communication (OCC), particularly suited for Visible Light Positioning (VLP) scenarios. Instead of the standard approaches of modulating the light source with a square wave, binary sequence or M-Pulse Amplitude Modulation (PAM) sequence, we propose that each beacon transmits filtered pseudo-random noise samples with a unique spectral signature. This allows us to circumvent the problem of having a low number of samples per image and the lack of time synchronisation between them, since there is no need for temporal alignment of random samples. The proposed concept was experimentally validated for a distance of up to 5 m, and the results showed that the probability of correct beacon identification increased with the number of images used. Furthermore, all beacons were correctly identified when using at least 10 images. These results indicate that this new proposed approach increases the number of beacons that can be identified, provided that a suitable number of images are used.

Optical Camera Communication (OCC) is a candidate technology for short-range intra-satellite links due to electromagnetic immunity and reduced harness complexity. In frame-wise reception (global-shutter operation), OCC throughput is constrained by the camera frame rate, motivating higher spectral-efficiency modulation at a fixed symbol clock. This work investigates M-ary pulse-amplitude modulation (PAM) for frame-based OCC and presents an end-to-end GS-PAM system, including the transmitter/receiver architectures, a statistically driven training method for selecting PAM intensity levels under camera noise and quantization constraints, and a frame-based demodulation pipeline for synchronization, amplitude estimation, quantization, and symbol reconstruction. Laboratory line-of-sight experiments demonstrate error-free transmission of 1,000 random ASCII characters using 4-PAM, achieving a twofold throughput increase over binary modulation under identical reception settings. An estimated SNR of at least 22 dB indicates sufficient margin for reliable multi-level detection. These results support PAM as an effective approach for improving throughput in low-rate, high-reliability intra-satellite OCC links.

This work investigates Pulse-Width Modulation (PWM) and Frequency Modulation (FM) as analog modulation schemes suitable for rolling shutter cameras. A theoretical and simulation framework is developed to model the rolling-shutter sampling process and evaluate signal reconstruction performance. The influence of key system parameters, including carrier frequency, modulating signal bandwidth, modulation index, and camera line sampling rate, is analyzed using the root-mean-square error (RMSE). Additionally, the impact of rolling-shutter line timing jitter is examined. Results show that FM provides lower reconstruction error under nominal conditions, while PWM exhibits greater robustness under large timing jitter. These findings highlight important trade-offs when selecting modulation schemes for OCC-based sensing systems.

Grapevine diseases represent a major threat to vineyard productivity, with Black Rot being among the most destructive due to its rapid spread and visual similarity to other diseases. These diseases are associated with a diversity of pathogenic agents, namely fungi, oomycetes, bacteria and pests. While prior work frequently reports high accuracy in controlled multi-class classification, practical deployments commonly require selective detection of a target disease against a contaminated negative class. In this work, Black Rot detection is formulated as a binary classification task, where the negative class includes healthy leaves and other visually similar diseases. This study employed ImageNet pretrained Convolutional Neural Network (CNN) backbones, MobileNetV2, DenseNet121, ResNet50 and VGG16, using a two-stage transfer learning protocol. The ability of the CNN models to accurately identify Black Rot cases was evaluated using standard classification metrics, namely accuracy, precision, recall and F1-score. The results show clear differences in detection behaviour across architectures. ResNet50 achieves the highest overall performance, obtaining 100.0% precision, with no false positives while maintaining a high recall 96.3% and a F1-score of 98.1%, with an accuracy of 98.9%. Overall, the achieved performance is competitive and exceeds values reported in the literature, while addressing a more realistic contaminated-negative scenario.

Optical Camera Communication (OCC) has emerged as a promising branch of Optical Wireless Communications (OWC), leveraging the unlicensed optical spectrum and widespread camera-equipped devices to enable low-cost, secure, and interference-resilient communication. As Internet of Things (IoT) deployments grow, conventional radio-frequency (RF) technologies face challenges related to spectrum congestion and electromagnetic interference. OCC addresses these limitations by offering a complementary solution for IoT applications where moderate data rates can be traded for robustness, spatial selectivity, and seamless integration with existing infrastructure. This review provides a comprehensive overview of OCC technologies, examining both transmitter and receiver architectures. Furthermore, this work identifies technical challenges hindering large-scale adoption and outlines emerging research directions towards sixth-generation (6G) networks. Special emphasis is placed on Integrated Sensing and Communication (ISAC) paradigms, and on distributed intelligent OCC networks.

This paper presents the design and experimental validation of an energy-autonomous optical camera communication (OCC) transmitter node intended for intra-satellite links. The proposed prototype harvests optical energy using a photovoltaic cell and stores it in an ultracapacitor, enabling threshold-triggered burst transmissions without electrical connection to a power bus. A laboratory demonstrator is characterized in terms of charge-transmit operating cycles and energy budget metrics, showing repeatable autonomous behavior with a charging time of approximately 199 s, burst durations of approximately 21 s, payloads of 315 bits per burst, a duty cycle of 9.6%, and an effective throughput of 1.43 bps. The results highlight how energy availability governs the effective throughput and motivates energy-aware OCC design for modular spacecraft subsystems.

This paper presents a real-time Optical Camera Communication (OCC) system for sensor-data transmission using a side-emitting optical fiber as a distributed light transmitter and a rolling-shutter camera as the receiver. Sensor data are packetized and sequentially transmitted using On-Off Keying modulation with Manchester encoding, while all receiver-side processing is done in real time. Region of Interest (ROI) detection is achieved using a Minimal Spanning Tree (MST)-based approach, enabling reliable tracking of the side-emitting fiber under varying distances. Experimental evaluation demonstrates stable real-time operation at approximately 47.5 fps across all tested conditions. For transmitter-receiver distances up to about 150 cm, the system achieves a low Bit Error Rate (BER) and near-unity Success of Reception (SoR). The presented results confirm the feasibility of low-cost, real-time OCC links for short-range sensor-data transmission using side-emitting optical fibers and provide a solid foundation for future improvements.