059 - Application of photonics technology for PNT user equipment
The demand for seamless positioning of IoT devices both outdoors and indoors is an important requirement for many logistic applications relevant to the digital transformation of industry. This is becoming more relevant as the degree of automation in industrial operations increases, together with the need of permanently tracking the location of inputs from suppliers, to be able to forecast potential disruptions in the supply chain.
IoT seamless tracking raises fundamental issues:
- low power consumption of the receivers: PNT sensors used in IoT devices must able to work over long periods of time (in some cases over five years) with minimal battery;
- time to first fix (TTFF): in some applications, IoT devices have to be able to turn on and calculate a position fix as soon as possible, then reporting (or storing) position and turn off again. TTFF is critical for power consumption and battery durability.
- hybridization of PNT sensors, to ensure seamless outdoors and indoor interoperability.
Previous works have concluded that the main drivers to GNSS power consumption are the baseband processing (signal correlation, in particular at low signal to noise ratio level and in acquisition), the RFFE front-end functions (RF, ADC) and, idle mode (leak current and energy required to maintain the receiver in a state compatible with short TTFF and efficient acquisition upon wake-up). Efficient signal acquisition are also instrumental to the TTFF, in particular at low signal to noise ratio and/or for complex signals and waveforms.
Photonic technology offers the possibility of implementing RF signal processors with lower power consumption and broader bandwidths than traditional electronic RF signal processors. Photonic correlators are used nowadays in passive, synthetic aperture millimeter-wave (MMW) imaging, radars or electronic warfare systems. Exploring the potential of photonic technology for the implementation of hybrid PNT sensors potentially combining GNSS and other signals suitable for indoor positioning seems an interesting avenue to develop low power, low TTFF receivers for applications in IoT for industrial systems. In addition, the technology could spin into PNT to support more advanced acquisition engines, reducing power consumption.
The objective of the activity is to investigate and proof the concept of lowering the power consumption of PNT engines, for instance in IoT devices, or enhancing the processing capabilities without increasing power consumption, by using photonics technologies and processors.
The tasks to be performed include:
- assessment of which components of the traditional GNSS receivers (e.g. RF front end, AD converter, baseband correlator) could be suitably implemented and improved using photonic technology;
- analysis of RF signal processing combination with different localization systems (e.g. GNSS and WiFi) within the same photonic processors;
- implementation of a proof of concept, including breadboarding photonic circuits functions, testing performance and assessing achievable power saving;
The main results of the activity will provide:
- identification of opportunities offered by photonics processors and technologies in future PNT user equipment;
- breadboards of the photonics-based processors, associated PNT user equipment and testing environments;
- results of test campaigns for different use cases.