Signal strength variations at 2 GHz for three sea paths in the British Channel Islands: observations and statistical analysis.

Measurements of signal strength are reported for a study of UHF propagation on three transhorizon sea paths in the British Channel Islands. Enhancements of up to 30 dB from the mean occur for periods of hours or days, especially in the summer, and constitute about 5% of the overall data. The probability distribution of received power is tabulated for the three paths and various antenna heights, and is compared with predictions of signal strength using ITU-R Recommendation P.1546-2. The difference between median and upper decile in the data is much less than predicted, whereas the difference between upper decile and the upper percentile is much greater than predicted

MIMO communications within the HF band using compact antenna arrays

Measurements have been made over a 255 km radio path between Durham and Leicester in the UK in order to investigate the potential applicability of multiple input multiple output (MIMO) techniques to communications within the HF band. This paper describes the results from experiments in which compact heterogeneous antenna arrays have been employed. The results of these experiments indicate that traditional spaced HF antenna arrays can be replaced by compact, active, heterogeneous arrays in order to achieve the required levels of decorrelation between the various antenna elements. An example case study is also presented which highlights the importance of the variable nature of the ionosphere in the context of HF-MIMO radio links

Transhorizon radiowave propagation due to evaporation ducting: the effect of tropospheric weather conditions on VHF and UHF radio paths over the sea

A detailed description of evaporation ducts and their relevance to radiowave propagation over the sea has been presented. The constantly changing weather conditions over the sea mean that marine and coastal environments, in particular, are prone to these unusual tropospheric phenomena that facilitate radio waves to have higher signal strengths and to travel longer distances than expected. Therefore, the influence of evaporation ducts on over-sea radiowave propagation needs to be thoroughly investigated. Research in this area will have implications for maritime communication systems used in coastal cellular telephone networks, commercial shipping, naval radar operations and sea-rescue

The use of heterogeneous antenna arrays in experimental HF-MIMO links

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International Dimension of research collaboration

Grand challenges, such as global warming or chronic and infectious diseases, are increasingly global and complex. Solving these challenges often requires international research collaboration. The European Commission is playing an increasing role in supporting research and innovation through Horizon 2020, the European Union's comprehensive Framework Programme for Research and Technological Development. This policy brief provides an overview of the main research priorities, the main collaborative efforts in international research collaboration regarding grand challenges, and summarises the outcomes of an expert and stakeholders' workshop conducted on the 3rd of April 2014. The brief is written to inform the European Research and Innovation Area Board regarding the state of research collaboration on grand challenges and what the EU could do to further improve research collaboration on these grand challenges