LCVAE-CNN: Indoor Wi-Fi Fingerprinting CNN Positioning Method Based on LCVAE

While Wi-Fi received signal strength indicator (RSSI) fingerprinting has emerged as a prominent solution for indoor positioning, its accuracy remains hindered by labor-intensive data collection and environmental variability. To overcome these challenges, we propose a novel LCVAE-CNN methodology that integrates a location-conditioned variational autoencoder (LCVAE) and a multitask convolutional neural network (CNN) to enhance data quality and positioning performance. The LCVAE employs a dual-encoder architecture to augment RSSI fingerprints by jointly modeling signal features and spatial dependencies, introducing three key innovations: 1) dual-stream encoding that decouples RSSI and location processing for more effective feature learning; 2) a geospatial loss function that enforces topological consistency in the generated data; and 3) conditional data augmentation that preserves physical constraints of indoor spaces. The multitask CNN then leverages shared feature extraction to jointly optimize classification and regression tasks, enabling efficient and accurate positioning. Extensive evaluations on the UJIIndoorLoc and Tampere datasets demonstrate the superiority of the LCVAE-CNN that achieves 98.80% floor classification accuracy with a mean positioning error (MPE) of 6.79 m on UJIIndoorLoc, whereas 97.22% accuracy with a MPE of 5.44 m on the Tampere dataset. Compared to five state-of-the-art methods, it improves floor accuracy by at least 1.9% and reduces MPE by over 19%, while maintaining comparable computational overhead, thereby achieving superior accuracy-efficiency tradeoffs.