Imec says smart systems will solve challenges

In terms of the 'big picture' areas, imec is addressing healthcare, sustainable energy and a range of sectors bundled under the heading of 'smart systems'. One of the main themes within smart systems is cognitive – or 'green' – radio. Liesbet van der Perre, director of imec's green radios program, said: "An important element of the work is that it is aimed at next generation applications. We're not just looking for more throughput, we also looking to add more intelligence." The work is being done in the context of demand for higher wireless data rates and more network capacity. "The Wireless World Research Forum says that, by 2020, there will be 7trillion devices serving 7billion people," van der Perre continued. "To meet those requirements, radios in 2020 will need to be 3000 times better than today's." This improvement will come in a number of small ways – power amplifier efficiency will need to double, with a threefold improvement from scalable processing modes. But much larger gains will be needed. "For instance," van der Perre noted, "we will get a 50 fold improvement using hybrid small cell architectures and an x19 improvement in router and switch hardware efficiency." van der Perre believes one way forward is reconfigurable radios. "LTE is becoming a flexible standard on its own, using different frequencies. Even 4G won't be one standard and radios will connect using the best possible link." She believes there are a lot of underused frequencies in the radio spectrum. "We can find these and use them for communications. But we need to know where the spectrum is and to develop multimode devices that can use the spectrum." An initial approach has been developed in the shape of Cobra – a cognitive baseband radio. This flexible solution is targeted at 4G requirements, providing up to 1Gbit/s throughput and multiple asynchronous concurrent streams. "We have upgraded the interconnect for data and control to support several high capacity streams in parallel and have also upgraded the ADRES processor," she noted. Other areas include FlexFEC, a flexible forward error correction processor described by van der Perre as a 'future proof Swiss Army Knife approach', and an application specific integrated processor (asip) based digital front end. van der Perre added: "The digital front end supports flexible filtering, synchronisation and spectrum sensing." Working with Holst Centre, imec has developed highly sensitive integrated sensing elements for gas detection. The polymer coated microbridges, created in high density arrays, can detect gases at concentrations in the parts per million level using on chip integrated read out techniques. According to the researchers, the technology is suitable for miniaturisation and consumes less than 1µW per bridge. The design allows for rapid coating of a range of absorbents on individual microbridges using inkjet printing technology. The suspended structures vibrate individually and their resonance changes in proportion to the amount of a particular substance which absorbs on their coatings. Because the bridges have a high length to thickness ratio, they have high sensitivity to low concentration of gas.