Section: Overall Objectives

Scientific challenges

Having a clear idea of relevant research areas in sdr is not easy because many parameters are not related to economical cost. For instance, military research has made its own development of sdr for its particular needs: US military sdr follows the sca communication architecture  [50] but this is usually not considered as a realistic choice for a commercial sdr handset. The targeted frequency band has a huge impact as sampling at high rates is very expensive, and trade-offs between flexibility, complexity, cost and power consumption have a big influence on the relative importance of the hot research topics.

Here are the relevant research domains where efforts are needed to help the deployment of sdr :

• Antennas and RF Front-Ends: This is a key issue for reducing interference, increasing capacity and reusing frequency. Hot topics such as wake-up radio or multi protocol parallel radio receivers are directly impacted by research on Antennas. Socrate has research work going on in this area.

• Analog to Digital Converters: Designing low-power high frequency adc is still a hot topic rather studied by micro-electronics laboratories (Lip6 for instance in France).

• Architecture of sdr systems: The ideal technology for embedded sdr still has to be defined. Hardware prototypes are built using fpga s, Asics and dsp s, but the real challenge is to handle a Hardware/Software design which includes radio and antennas parts.

• Middleware for sdr systems: How to manage, reconfigure, update and debug sdr systems is still an open question which is currently studied for each sdr platform prototype. Having a common programming interface for sdr systems in one research direction of Socrate.

• Distributed signal processing: Cognitive, smart or adaptive radios will need complex decision algorithms which, most of the time will need to be solved in a distributed manner. Socrate has clearly a strong research effort in that direction. Distributed information theory is also a hot research topic that Socrate wishes to study.