{'fraction_non_alphanumeric': 0.027555555555555555, 'fraction_numerical': 0.0035555555555555557, 'mean_word_length': 5.584795321637427, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Line-of-sight distance extension of rolling-shutter OCC using dual-camera spatial luminance distribution

Rolling-shutter (RS) optical camera communication (OCC) increases the symbol rate much faster than the frame rate of the image sensor. However, transmission distance extension while maintaining sufficient throughput is a technical issue to resolve for indoor OCC. In this study, to increase line-of-sight (LOS) transmission distance and to improve maximum data rate further, RS OCC based on symbol decision using dual-camera spatial luminance distribution is demonstrated. Even at long distance where conventional pixel value threshold is not available for symbol decision and distance extension, two-step thresholds based on spatial luminance distribution are effective for the decision and extension. In addition, ensemble averaging in spatial luminance distribution with dual cameras increases the symbol rate further. In RS OCC using dual-camera spatial luminance distribution, LOS transmission distance increases up to 2.4 meters under error-free conditions. Throughput degradation is suppressed within 36 percent.