Sensors for locating and identifying people indoors are currently extensively designed to monitor and automate systems. In the field of home automation, location sensors have become a key factor. There are different types of sensors that differ in their distinctive features: data processing, ease of installation, ease of use, privacy management: the latter is really important due to scalpers of the data of users in modern society. For these reasons, a localization system should have some particular features such as being tagless, secure the user's privacy and passive. In fact some localization systems require people to wear or carry a tag to be monitored.