Fig. 2
From: Block-sparsity-based localization in wireless sensor networks

Illustration of training phase (left) and runtime phase (right): in the training phase, each RP transmits T times to the BSs, which in turn send the data to the central unit that collects the signature map; in the runtime phase, a device is placed in cell and transmits to the BSs, which forward the information to the central unit, which tries to localize the device using the database