5 research outputs found

    Rapid prototyping and validation of FS-FBMC dynamic spectrum radio with simulink and ZynqSDR

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    This paper presents the research carried out in developing and targeting a novel real-time Dynamic Spectrum Access (DSA) Frequency Spread Filter Bank Multicarrier (FS-FBMC) transmitter prototype to programmable ‘ZynqSDR’ Software Defined Radio (SDR) hardware, and introduces a series of experiments used to validate the design’s ‘cognitive’ DSA capabilities. This transmitter is a proof of concept, that uses DSA techniques to enable Secondary Users (SUs) to access the band traditionally used for FM Radio broadcasting (88-108 MHz), and establish data communication channels in vacant parts of the FM Radio Primary User (PU) spectrum using a multicarrier modulation scheme with a Non Contiguous (NC) channel mask. Once implemented on the hardware, the transmitter is subjected to various FM Radio environments sampled from around Central Scotland, and it is demonstrated that it can dynamically adapt its NC transmitter mask in real time to protect the FM Radio signals it detects. A video is presented of this dynamic on-hardware spectral reconfiguration, and the reader is encouraged to view the video to appreciate the responsiveness of the design. An investigation into potential FBMC guardband sizes is carried out, with initial findings indicating a guardband of 200 kHz (either side of an FM Radio station) is required in order to prevent interference with the PUs. This paper also demonstrates the capabilities of the MATLAB¼/ Simulink ZynqSDR workflow, and provides a case study and reference design that we feel other researchers working in this field can benefit from

    Insect pollinators: linking research and policy. Workshop report.

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    EXECUTIVE SUMMARY Pollinators interact with plants to underpin wider biodiversity, ecosystem function, ecosystem services to agricultural crops and ultimately human nutrition. The conservation of pollinators is thus an important goal. Pollinators and pollination represent a tractable example of how biodiversity can be linked to an ecosystem service. This represents a case study for exploring the impacts of various policy instruments aiming to halt/reverse the loss of ecosystem services. There is a need to understand how multiple pressures (e.g. habitat loss, fragmentation and degradation, climate change, pests and diseases, invasive species and environmental chemicals) can combine or interact to affect diversity, abundance and health of different pollinator groups. Decision makers need to balance consideration of the effects of single pressures on pollinators against the suite of other pressures on pollinators. For instance, the threat from pesticide use (with its high public and media profile) also needs to be considered in the context of the other threats facing pollinators and balanced against the need for food security. An independent review of the balance of risks across pollinator groups from pesticide use would help synthesise current knowledge into an accessible form for decision makers. To manage or lessen these threats to pollinators (wild and managed) and pollination requires improved knowledge about their basic ecology. We still need to know where and in what numbers different pollinator species occur, how they use different environments, how they interact with each other through shared plants and diseases and how wild pollinator abundance is changing. Decision makers need clear factual evidence for i) the relative contribution of different managed and wild pollinator groups to wildflower and crop pollination and ii) how this varies across different land-uses, ecosystems and regions. Addressing these basic and applied questions will improve our ability to forecast impacts on pollination service delivery to agricultural crops arising from current and future environmental changes, pesticide use and emerging diseases. The development of a long-term, multi-scale monitoring scheme to monitor trends in pollinator (wild and managed) population size and delivery of pollination services (ideally tied to data collection on land-use, pesticide applications and disease incidence at relevant spatial scales) would provide the evidence base for developing the effectiveness of policy and management interventions over time. Such a monitoring scheme would benefit from including research council organisations (e.g. CEH), governmental departments (e.g. Fera), universities, museums and NGOs (e.g. BBKA,SBA, Bumblebee Conservation Trust etc) Insect Pollinators: linking research and policy Workshop Report | 5 In the context of agricultural intensification and conservation we need to establish what type, quality and quantity of interventions (e.g. agri-environment schemes, protected areas) are needed, where to place them and how they can sustain different pollinator populations and effective pollination services. Current monitoring of the risks from diseases and pesticides requires broadening to consider other insects aside from honey bees, unless we can demonstrate that honey bees are good surrogates for all other pollinators. There is a need to increase confidence in regulatory risk assessments pertaining to pathogens and pesticides by incorporating other pollinator species, investigating chronic exposure to multiple chemicals and using field relevant dosages (specific to regions, not using other data sources as surrogates). At present the effects of spatial, social and temporal scales on the benefits stakeholders receive from pollination services are only beginning to be understood. Economic valuation of pollination services can help optimise the cost-effectiveness of service management measures and offer new opportunities to incentivise action or raise awareness among stakeholders. Novel tools and instruments (e.g. education and training) are needed to translate broad international (e.g. CBD, EU Biodiversity Strategy) and national (e.g. England‟s Biodiversity Strategy) policies into local actor (e.g. beekeeper, farmer, citizen scientist) contributions to meet biodiversity commitments Refocusing some public funding to link basic science to development of practical solutions (e.g. better crop protection products, improved disease resistance or treatment) could help science deliver better-targeted evidence for pollinator protection. Scientists need to make more use of opportunities (e.g. POSTnotes1; practitioner guides) to transfer knowledge to a broad audience in order to better influence decision maker and practitioner behaviours. Improved knowledge exchange between scientists and decision makers is important to combating threats to pollination. Central to this is improved understanding of the respective positions of policy makers and scientists. For instance, policy-makers usually need to be presented with a range of options to balance against other areas of policy. Science does not always arrive at a consensus due to uncertainties in data or models. Policy-makers need to understand that scientists are communicating the “best available knowledge at present” and that consequently it is not always possible to give a definitive answer

    Concept design of the LiteBIRD satellite for CMB B-mode polarization

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    LiteBIRD is a candidate for JAXA's strategic large mission to observe the cosmic microwave background (CMB) polarization over the full sky at large angular scales. It is planned to be launched in the 2020s with an H3 launch vehicle for three years of observations at a Sun-Earth Lagrangian point (L2). The concept design has been studied by researchers from Japan, U.S., Canada and Europe during the ISAS Phase-A1. Large scale measurements of the CMB B-mode polarization are known as the best probe to detect primordial gravitational waves. The goal of LiteBIRD is to measure the tensor-to-scalar ratio (r) with precision of r < 0:001. A 3-year full sky survey will be carried out with a low frequency (34 - 161 GHz) telescope (LFT) and a high frequency (89 - 448 GHz) telescope (HFT), which achieve a sensitivity of 2.5 \u3bcK-arcmin with an angular resolution 30 arcminutes around 100 GHz. The concept design of LiteBIRD system, payload module (PLM), cryo-structure, LFT and verification plan is described in this paper
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