814 research outputs found

    Near-Instantaneously Adaptive HSDPA-Style OFDM Versus MC-CDMA Transceivers for WIFI, WIMAX, and Next-Generation Cellular Systems

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    Burts-by-burst (BbB) adaptive high-speed downlink packet access (HSDPA) style multicarrier systems are reviewed, identifying their most critical design aspects. These systems exhibit numerous attractive features, rendering them eminently eligible for employment in next-generation wireless systems. It is argued that BbB-adaptive or symbol-by-symbol adaptive orthogonal frequency division multiplex (OFDM) modems counteract the near instantaneous channel quality variations and hence attain an increased throughput or robustness in comparison to their fixed-mode counterparts. Although they act quite differently, various diversity techniques, such as Rake receivers and space-time block coding (STBC) are also capable of mitigating the channel quality variations in their effort to reduce the bit error ratio (BER), provided that the individual antenna elements experience independent fading. By contrast, in the presence of correlated fading imposed by shadowing or time-variant multiuser interference, the benefits of space-time coding erode and it is unrealistic to expect that a fixed-mode space-time coded system remains capable of maintaining a near-constant BER

    Adaptive Wireless Networking

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    This paper presents the Adaptive Wireless Networking (AWGN) project. The project aims to develop methods and technologies that can be used to design efficient adaptable and reconfigurable mobile terminals for future wireless communication systems. An overview of the activities in the project is given. Furthermore our vision on adaptivity in wireless communications and suggestions for future activities are presented

    Utilizing code orthogonality information for interference suppression in UTRA downlink

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    IST-2000-30148 I-METRA: D4 Performance evaluation

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    This document considers the performance of multiantenna transmit/receive techniques in high-speed downlink and uplink packet access. The evaluation is done using both link and system level simulations by taking into account link adaptation and packet retransmissions. The document is based on the initial studies carried out in deliverables D3.1 and D3.2.Preprin

    IST-2000-30148 I-METRA: D6.1 Implications in re-configurable systems beyond 3G (Part 1)

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    In this activity MIMO HSDPA is evaluated as the UMTS evolution that could allow a combination of high bit rate services, coverage and mobility with a good trade-off between cost and performance. This evaluation requires the definition of an objective framework for comparison between competing air interface technologies for Systems beyond 3G, and should be carried out in cooperation with other IST projects. The deliverable is complemented by analytically assessing channel capacity in flat Rician- and Rayleigh fading when ideal proportional fast scheduling, optimal rate adaptation, and various transmit diversity techniques are used.Preprin

    IST-2000-30148 I-METRA: D3.1 Design, analysis and selection of suitable algorithms

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    This deliverable contains a description of the space-time coding algorithms to be simulated within the I-METRA project. Different families of algorithms have been selected and described in this document with the objective of evaluating their performance. One of the main objectives of the I-METRA project is to impact into the current standardisation efforts related to the introduction of Multiple Input Multiple Output (MIMO) configurations into the High Speed Downlink and Uplink Packet Access concepts of UMTS (HSDPA and HSUPA). This required a review of the current specifications for these systems and the analysis of the impact of the potential incorporation of the selected MIMO schemes.Preprin

    IST-2000-30148 I-METRA: D3.2 Implementation of relevant algorithms

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    This deliverable provides a high level description of the software developed within the I-METRA project following the selection reported in D3.1 "Design, Analysis and Selection of Suitable Algorithms".Preprin

    EVEREST IST - 2002 - 00185 : D23 : final report

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    Deliverable públic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version
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