New developments in how antennas handle signals in today's crowded airwaves should help make wireless communication and location services faster and vastly more accurate. Emergency services, e-health, cyber security and other areas depending on reliable data transmission stand to benefit from a breakthrough EU-funded research that improves location estimation accuracy by 60%.
The better a radio antenna can capture signals, the more reliable the data transfer. Good data transfer improves the quality of reception in the case of a cell phone or the ability to use proximity or location-based services, such as in emergency situations, tracing cyber-security threats, or for advertising and marketing.
For example, if you are searching for a pharmacy, accurate proximity could take you to within 40 metres of the store. But if you are lost in rough seas, nothing less than, say, three-metre accuracy would do. The EU-funded project, 'Research on location estimation in multi-carrier systems' (Realmars), is expected to help mobile carriers keep ahead of the growing demand being put on the airwaves.
"There is only so much traffic that can pass through the airwaves before signals start interfering with one another and affecting the quality of service," explains Günes Karabulut Kurt of Istanbul's Technical University's Faculty of Electrical and Electronics Engineering who headed the Realmars project.
The telecom sector needs to find smarter ways to use the available spectrum – the radio frequencies on which all communication signals travel – more efficiently. According to the Digital Agenda for Europe's mid-term review, greater data consumption and a shift to mobile technologies, such as smartphones and mobile services, are the most significant trends in the telecoms sector.
Clever way of boosting signals
Realmars' breakthrough is expected to help telecom carriers deliver better services despite the added pressure on mobile systems caused by greater demand for data and better transmission quality. The project developed algorithms (tiny programs) which read the data being transmitted to and from antennas much better, thus greatly improving the accuracy of signal approximation.
"This could make a big difference in life-saving situations," says Dr Kurt. She came up with the idea for Realmars following her PhD studies on signal estimation and later work with the Turkish telecom giant Turkcell on multi-carrier (MC) systems – these tackle the crowding of radio waves by splitting and sending data over separate carrier signals.
Under Dr Kurt's guidance, Realmars examined a clever way of boosting 'Orthogonal frequency division multiplexing' (OFDM). This is an MC technology used today in many wireless platforms like WiMAX and late-generation mobile internet (3G, 4G, LTE). The project's focus was on how to upgrade OFDM antenna systems to make them more adaptive or indeed 'receptive' to incoming signals.
Dr Kurt worked on ways to enhance incoming signal strength by improving an antenna's ability to judge or 'estimate' the angles of arrival (AOA). This, she predicted (correctly), would create more possibilities for location-based services, especially in important areas such as e-health, emergency response and cyber security.
"Using MC signals and our AOA algorithms and tools, we can improve location estimation accuracy by 60% compared to current technologies on the market," notes Dr Kurt. These results were reached through a complex process, including innovative use of physical layer characteristics with higher application layers and the integration of so-called "tree search structures" into these algorithms to further boost performance.
Realmars developed a toolbox or framework that is easy to use for marketing and high-tech applications, for instance. Part of the work carried out by the team is available on the project website as open source for anyone to use or further develop. Other commercially protected parts are being further developed by Dr Kurt's former employer Turkcell. Patents have also been filed for Realmars' location estimation system.