New terrestrial broadcast TV networks are being rolled out around the world, and broadcast network operators and regulators are looking closely at the efficiency and performance of these networks. The pressure is on to review the existing uses of the radio spectrum, and to see if there are better ways to achieve the same service, using new techniques and the development of second generation standards for the coding and modulation of the broadcast TV signals. This session will look in detail at some of the most innovative proposals that are being trialled and evaluated.
“Time Frequency Slicing” (TES) is a technique that achieves increased frequency diversity by allowing each service to be transmitted by frequency hopping over several RF channels – potentially spreading the service over hundreds of MHz. Theoretical results indicate improved robustness and a spectral efficiency gain of around 50%.
Another frequency agile system under investigation in several countries is based on the use of “White Space Devices” (WSD) which take advantage of locally unused spectrum within the UHF broadcast TV band. A number of WSD technologies are now emerging, and operating scenarios are being assessed for both rural and suburban environments.
The important issues for these techniques are the protection of existing primary broadcast services from interference, and the need for a geo-location database of permitted frequencies and powers.
We are becoming familiar in our homes with new WiFi standards that employ multiple input multiple output (MIMO) communication channels between the internet router and our PCs. Broadcast TV networks can benefit too from the additional robustness of such multiple antenna configurations, and multiple input single output systems (MISO) can be deployed to overcome the spectrum ripples and gaps that appear for single antenna systems due to multipath interference.
This session will explain the background to these new technologies and provide delegates with a unique insight into their potential impact.
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