In the context of wireless sensor networks (WSN), our interest is focused on the physical layers for low complexity sensors or heterogeneous networks of sensors with scalable complexity. After having worked on  Ultra-Wide Band technology (UWB) in the past, now recent research lines are focused on low energy localization techniques, synergies between encoding and positioning, innovative strategies for spectrum management and interference reduction. The main goal is to contribute to the basis for the deployment of networks composed by numerous, heterogeneous devices with the characteristic of being energy efficient, self-configuring and possibily sensitive to the variation of the environment around their location. These studies are now considered also in the context of 5G integration of IoT and machine communication.

Publications

Projects and collaborations

Simulation tools

Encoding and positioning
	In the context of fingerprinting (FP) applications, we investigate the reduction of quantization in the Received Signal Strength Indicator (RSSI) till to the binary level. The computational complexity can be limited reducing the RSSI quantization till to a simple binary indicator at the expense of an increased number of reference points or beacons. This approach, usually not advanatageous for most of the wireless technologies, can be considered when we use very small, inexpensive beacons, like those based on BLE technology, RFID or in the future context of the Internet of Things. So, for the two level quantization, we propose a performance estimation method introducing the association of FP deployment to an error correcting code [16b][17f].
Low energy ranging and localization
	We are investigating ways for enhancing the integration between the estimate of the distance / angles with the data processing necessary to get the position of the nodes inside a network. Moreover ranging information can be used for other cross-optimization procedures. New ranging techniques that provide more information about distances and their reliabilities have been introduced in the past (soft ranging, [07d, 08d]). Now we are currently focusing on localization techniques with high energy efficiency [10c,13c,14a] and low complexity for microsensors or IoT applications.
Performance analysis
	Results have been obtained in the performance evaluation of RAKE receivers in the presence of multiple access interference with both exponential (Nakagami) and realistic (IEEE 802.15.3a for UWB-IR [06a, 09a]) multipath channel profiles.