ViFi-Loc: Multi-modal Pedestrian Localization using GAN with Camera-Phone Correspondences

In Smart City and Vehicle-to-Everything (V2X) systems, acquiring pedestrians' accurate locations is crucial to traffic and pedestrian safety. Current systems adopt cameras and wireless sensors to estimate people's locations via sensor fusion. Standard fusion algorithms, however, become inapplicable when multi-modal data is not associated. For example, pedestrians are out of the camera field of view, or data from the camera modality is missing. To address this challenge and produce more accurate location estimations for pedestrians, we propose a localization solution based on a Generative Adversarial Network (GAN) architecture. During training, it learns the underlying linkage between pedestrians' camera-phone data correspondences. During inference, it generates refined position estimations based only on pedestrians' phone data that consists of GPS, IMU, and FTM. Results show that our GAN produces 3D coordinates at 1 to 2 meters localization error across 5 different outdoor scenes. We further show that the proposed model supports self-learning. The generated coordinates can be associated with pedestrians' bounding box coordinates to obtain additional camera-phone data correspondences. This allows automatic data collection during inference. Results show that after fine-tuning the GAN model on the expanded dataset, localization accuracy is further improved by up to 26%.