Low complexity Turbo synchronization without initial carrier synchronization

Wireless data transmission results in frequency and phase offsets of the signal in the receiver. In addition the received symbols are corrupted by noise. Therefore synchronization and channel coding are vital parts of each receiver in digital communication systems. By combining the phase and frequency synchronization with an advanced iterative channel decoder (inner loop) like turbo codes in an iterative way (outer loop), the communications performance can be increased. This principal is referred to as turbo synchronization. For turbo synchronization an initial estimate of phase and frequency offset is required. In this paper we study the case, where the initial carrier synchronization is omitted and an approach with trial frequencies is chosen. We present novel techniques to minimize the number of trial frequencies to be processed. The communications performance and effort of our method is demonstrated. Furthermore the implementation complexity of the whole system is shown on a Xilinx FPGA

Design Space Exploration for Frequency Synchronization of BPSK/QPSK Bursts

Frequency synchronisation is a vital part of every inner receiver for wireless communication. In this paper we present different implementation alternatives for non data aided frequency estimation of BPSK/QPSK bursts with respect to implementation complexity and communications performance. Results with regard to different quantization levels, varying burstlengths, frequency offsets and modulation indices for different signal to noise ratios are presented. Implementation results are based on XILINX Virtex II Pro FPGA devices

Citizens' observatories for situation awareness in flooding

Citizens' observatories are emerging as a means to establish interaction and co-participation between citizens and authorities during both emergencies and the day-to-day management of fundamental resources. In this paper we present a case study in which a model of citizens' observatories is being been translated into practice in the WeSenseIt project. The WeSenseIt citizens' observatory provides a unique way of engaging the public in the decision-making processes associated with water and flood management through a set of new digital technologies. The WeSenseIt citizens' observatory model is being implemented in three case studies based in the UK, the Netherlands and Italy. We describe the findings and our experiences following preliminary evaluations of the technologies and the model of co-participation and describe our future research plans

Polar Code decoder exploration framework

The increasing demand for fast wireless communications requires sophisticated baseband signal processing. One of the computational intense tasks here is advanced Forward Error Correction (FEC), especially the decoding. Finding efficient hardware implementations for sophisticated FEC decoding algorithms that fulfill throughput demands under strict implementation constraints is an active research topic due to increasing throughput, low latency, and high energy efficiency requirements.This paper focuses on the interesting class of Polar Codes that are currently a hot topic. We present a modular framework to automatically generate and evaluate a wide range of Polar Code decoders, with emphasis on design space exploration for efficient hardware architectures. To demonstrate the efficiency of our framework a very high throughput Soft Cancellation (SCAN) Polar Code decoder is shown that was automatically generated. This decoder is, to the best of our knowledge, the fastest SCAN Polar Code decoder published so far.</p

A new Architecture for High Speed, Low Latency NB-LDPC Check Node Processing

International audience—Non-binary low-density parity-check codes have superior communications performance compared to their binary counterparts. However, to be an option for future standards, efficient hardware architectures must be developed. State-of-the-art decoding algorithms lead to architectures suffering from low throughput and high latency. The check node function accounts for the largest part of the decoders overall complexity. In this paper a new hardware aware check node algorithm and its architecture is proposed. It has state-of-the-art communications performance while reducing the decoding complexity. The presented architecture has a 14 times higher area efficiency, increases the energy efficiency by factor 2.5 and reduces the latency by factor of 3.5 compared to a state-of-the-art architecture

A code-aided synchronization IP core for iterative channel decoders

Synchronization and channel decoding are integral parts of each receiver in wireless communication systems. The task of synchronization is the estimation of the general unknown parameters of phase, frequency and timing offset as well as correction of the received symbol sequence according to the estimated parameters. The synchronized symbol sequence serves as input for the channel decoder. Advanced channel decoders are able to operate at very low signal-to-noise ratios (SNR). For small values of SNR, the parameter estimation suffers from increased noise and impacts the communication performance. To improve the synchronization quality and thus decoder performance, the synchronizers are integrated into the iterative decoding structure. Intermediate results of the channel decoder after each iteration are used to improve the synchronization. This approach is referred to as code-aided (CA) synchronization or turbo synchronization. A number of CA synchronization algorithms have already been published but there is no publication so far on a generic hardware implementation of the CA synchronization. Therefore we present an algorithm which can be implemented efficiently in hardware and demonstrate its communication performance. Furthermore we present a high throughput, flexible, area and power efficient code-aided synchronization IP core for various satellite communication standards. The core is synthesized for 65 nm low power CMOS technology. After placement and routing the core has an area of 0.194 mm2, throughput of 207 Msymbols/s and consumes 41.4 mW at 300 MHz clock frequency. The architecture is designed in such a way that it does not affect throughput of the system

Citizens observatories for effective Earth observations: the WeSenseIt approach

The WeSenseIt project defines citizen observatories as “A method, an environment and an infrastructure supporting an information ecosystem for communities and citizens, as well as emergency operators and policymakers, for discussion, monitoring and intervention on situations, places and events” . A collaborative approach has been taken to develop solutions that involve an exchange of information and expertise from all participants and where the focus is on arriving at practical solutions with a clear vision and direction. This has created a shared ownership scheme, and shifts power to the process itself rather than remaining within authorities, developers or decision-makers. The project’s emphasis is on delivering highly innovative technologies to support citizens, communities and authorities in developing a real-time situation awareness while ensuring all stakeholders play their part. Implementation has been through a combination of crowdsourcing, custom applications and dedicated web portals designed to foster collaboration, and which has created a shared knowledge base that facilitates decision-making processes and engages with communities. Data is captured via innovative sensors that are used directly by citizens, crowdsourcing from social networks (or by collective intelligence)

Knowledge for Change: A Decade of Citizen Science (2020–2030) in Support of the SDGs

In October 2020, the Museum für Naturkunde Berlin (MfN) with many partners, supported by the European Commission and the Federal Ministry of Education and Research (BMBF), held an international, hybrid conference in order to showcase, evaluate, and discuss the contribution of citizen science to frame and achieve the SDGs. The conference Knowledge for Change: A Decade of Citizen Science (2020-2030) in Support of the SDGs took place as an official event of Germany’s 2020 EU Council presidency. The SDGs are a scientifically based framework for the whole world to address hunger and malnutrition, health, environment as well as culture and justice, decided by the UN. Citizen Science, the contribution of lay people to scientific activities, may support the achievement of the SDGs – by providing data and insights, but also by adapting and prioritising research questions. Aim The conference presented, evaluated and discussed the exciting contributions that Citizen Science makes in framing and achieving sustainable development, specifically the UN SDGs. The conference brought together expertise from policy makers, institutional and citizen scientists, economists, NGOs and civil society to implement mechanisms and processes for the transition towards a more sustainable future. The Declaration A Declaration including policy recommendations resulted from the conference: "Our world – our goals: citizen science for the Sustainable Development Goals". The Declaration acts as a voluntary commitment by all partners to define the roles, competences and concrete potentials of Citizen Science to advance the SDGs. It was formulated in an open and participatory process. The Declaration groups the various important contributions of citizen science to the SDGs in three central recommendations: 1) Harness the benefits of citizen science for the SDGs, 2) strengthen citizen science and its connections with other communities, and 3) strengthen future citizen science systems