72 research outputs found

    Timing and Carrier Synchronization in Wireless Communication Systems: A Survey and Classification of Research in the Last 5 Years

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    Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to sample the incoming signal. Carrier synchronization is the process by which a receiver adapts the frequency and phase of its local carrier oscillator with those of the received signal. In this paper, we survey the literature over the last 5 years (2010–2014) and present a comprehensive literature review and classification of the recent research progress in achieving timing and carrier synchronization in single-input single-output (SISO), multiple-input multiple-output (MIMO), cooperative relaying, and multiuser/multicell interference networks. Considering both single-carrier and multi-carrier communication systems, we survey and categorize the timing and carrier synchronization techniques proposed for the different communication systems focusing on the system model assumptions for synchronization, the synchronization challenges, and the state-of-the-art synchronization solutions and their limitations. Finally, we envision some future research directions

    D 3. 3 Final performance results and consolidated view on the most promising multi -node/multi -antenna transmission technologies

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    This document provides the most recent updates on the technical contributions and research challenges focused in WP3. Each Technology Component (TeC) has been evaluated under possible uniform assessment framework of WP3 which is based on the simulation guidelines of WP6. The performance assessment is supported by the simulation results which are in their mature and stable state. An update on the Most Promising Technology Approaches (MPTAs) and their associated TeCs is the main focus of this document. Based on the input of all the TeCs in WP3, a consolidated view of WP3 on the role of multinode/multi-antenna transmission technologies in 5G systems has also been provided. This consolidated view is further supported in this document by the presentation of the impact of MPTAs on METIS scenarios and the addressed METIS goals.Aziz, D.; Baracca, P.; De Carvalho, E.; Fantini, R.; Rajatheva, N.; Popovski, P.; Sørensen, JH.... (2015). D 3. 3 Final performance results and consolidated view on the most promising multi -node/multi -antenna transmission technologies. http://hdl.handle.net/10251/7675

    D3.2 First performance results for multi -node/multi -antenna transmission technologies

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    This deliverable describes the current results of the multi-node/multi-antenna technologies investigated within METIS and analyses the interactions within and outside Work Package 3. Furthermore, it identifies the most promising technologies based on the current state of obtained results. This document provides a brief overview of the results in its first part. The second part, namely the Appendix, further details the results, describes the simulation alignment efforts conducted in the Work Package and the interaction of the Test Cases. The results described here show that the investigations conducted in Work Package 3 are maturing resulting in valuable innovative solutions for future 5G systems.Fantini. R.; Santos, A.; De Carvalho, E.; Rajatheva, N.; Popovski, P.; Baracca, P.; Aziz, D.... (2014). D3.2 First performance results for multi -node/multi -antenna transmission technologies. http://hdl.handle.net/10251/7675

    5G – Wireless Communications for 2020

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    Interference mitigation using group decoding in multiantenna systems

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    Cooperative Radio Communications for Green Smart Environments

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    The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin

    Kanavien yhdistämistekniikan suorituskyvyn arviointi edistyneissä LTE-järjestelmissä

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    Carrier Aggregation (CA) is an essential technology component in LTE-Advanced (LTE-A). CA is capable of combining up to five Long Term Evolution (LTE) carriers to be used for multicarrier transmission in both downlink and uplink. CA provides increased throughputs, additional capacity and possibilities for load balancing. This thesis presents the key features of CA. Furthermore, the results from CA performance measurements are analyzed and presented. The measurements were conducted in live network to evaluate the end-user experience. The objective was to determine whether CA is capable of delivering the performance that could be theoretically expected. The performance was measured in LTE-A radio network using 2x20 MHz bandwidth with 2x2 MIMO configuration and Category 6 User Equipment (UE). Only downlink CA was measured, since uplink CA capable UEs were not commercially available. The performance was evaluated with stationary and mobility measurements. The results indicate that CA is capable of providing the expected performance gain. In good radio conditions the maximum downlink throughput is close to the 300 Mbit/s. Furthermore, CA performs well in poor radio conditions. The performance gain can be more than 100 %, if the additional carrier is on an unused band. In CA, a secondary component carrier is configured for the UE, in addition to the primary carrier. The operation is performed in connected state either after connection setup or radio handover. The delay in secondary carrier addition was measured to evaluate the impact on user experience. The results indicate that the secondary carrier addition after connection setup or handover is sufficiently fast, and do not have an impact to the user experience.Kanavien yhdistäminen (engl. Carrier Aggregation) on oleellinen tekniikka edistyneessä Long Term Evolution järjestelmässä. Sen avulla on mahdollista yhdistää enintään viisi LTE taajuutta käytettäväksi monikanavaiseen ala- ja ylälinkin lähetykseen. CA mahdollistaa aiempaa suuremmat siirtonopeudet, lisää verkon kapasiteettia sekä antaa mahdollisuuden kuormanjakoon eri taajuuksien välillä. Tässä työssä esitellään CA:n keskeiset ominaisuudet. Lisäksi CA:n suorituskykymittauksien tulokset on analysoitu ja esitelty. Mittaukset toteutettiin operaattorin tuotantoverkossa, jotta loppukäyttäjän saamaa kokemusta on mahdollista arvioida. Tavoitteena oli selvittää, pystyykö CA tarjoamaan sellaista suorituskykyä, jota voidaan teorian perusteella odottaa. Suorituskykyä mitattiin LTE-radioverkossa käyttäen 2x20 MHz kaistanleveyttä ja 2x2 MIMO:n kokoonpanoa sekä kategorian 6 päätelaitetta. Mittaukset suoritettiin vain alalinkissä, sillä ylälinkin CA-kykyisiä päätelaitteita ei ollut kaupallisesti saatavilla. Suorituskykyä on arvioitu sekä piste- että mobiliteettimittauksilla. Tulokset osoittavat, että CA pystyy tarjoamaan oletetun suorituskyvyn parannuksen. Hyvissä radio olosuhteissa maksimi datanopeus alalinkissä on lähes 300 Mbit/s. Lisäksi CA toimii hyvin myös huonoissa radio-olosuhteissa. Suorituskyvyn parannus voi olla enemmän kuin 100 %, jos lisätty toinen kanava on vähemmän käytetyllä taajuuskaistalla. CA:ssa toissijainen kanava konfiguroidaan päätelaitteelle ensisijaisen lisäksi. Operaatio suoritetaan yhteystilassa joko yhteyden muodostamisen tai solunvaihdon jälkeen. Toissijaisen kanavan lisäämisen aiheuttama viive mitattiin, jotta sen vaikutus käyttökokemukseen voitiin arvioida. Tulokset osoittavat, että toissijaisen kanavan lisääminen yhteyden muodostamisen tai solunvaihdon jälkeen on riittävän nopea operaatio, eikä sillä ole vaikutusta käyttökokemukseen
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