The Experts below are selected from a list of 5487 Experts worldwide ranked by ideXlab platform
Xuefeng Liu - One of the best experts on this subject based on the ideXlab platform.
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Enhancing ZigBee throughput under WiFi interference using real-time Adaptive Coding
Proceedings - IEEE INFOCOM, 2014Co-Authors: Peng Guo, Jiannong Cao, Kui Zhang, Xuefeng LiuAbstract:Co-existing in the unlicensed ISM band, ZigBee transmissions can be significantly interfered by WiFi. Although several approaches recently are proposed to enable ZigBee transmission under WiFi interference, the ZigBee throughput still decreases to zero when WiFi throughput (generated by D-ITG) is over 8Mbps. In this paper, we propose a real-time (<; 5ms) Adaptive transmission (RAT) scheme to efficiently adapt forward error-correction Coding (FEC) on ZigBee devices in dynamic WiFi environment. We find that sizes of WiFi frames well follow the power law distribution model. With the model, corruption in ZigBee packets can be estimated to some extent, thus facilitating ZigBee device to choose a suitable FEC Coding to maximize the throughput. Extensive experimental results show that, compared with existing works, RAT achieves significant performance improvement of ZigBee transmissions in WiFi environment with different traffic load. Particularly, the ZigBee throughput of RAT can be about 10kbps when the WiFi throughput is 8Mbps.
Ivan B. Djordjevic - One of the best experts on this subject based on the ideXlab platform.
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OFC - SDN-Based Application Driven In-Band Adaptive Coding in Data Centers
Optical Fiber Communication Conference, 2020Co-Authors: Mingwei Yang, Houman Rastegarfar, Ivan B. DjordjevicAbstract:A software-defined Adaptive Coding scheme is experimentally implemented and evaluated for 50 Gbps 4-PAM optical switching in wavelength-routing DCs. Up to 1 dB reduction in transmission power is achieved with switching latencies of hundreds of milliseconds.
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OFC - Hysteresis-based Margin Allocation for Adaptive Coding in SDN-enabled Optical Networks
Optical Fiber Communication Conference, 2018Co-Authors: Yao Li, Mingwei Yang, Ivan B. Djordjevic, Weiyang Mo, Zhen Qu, Daniel C. KilperAbstract:Hysteresis-based margin-allocation for Adaptive Coding is experimentally investigated against PDL-induced OSNR fluctuations in a SDN-enabled multi-domain optical network. Up to 90% network outage reduction can be observed under different margins.
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SDN based in-band Adaptive Coding by distributed pseudonoise preamble detection in optical networks
Metro and Data Center Optical Networks and Short-Reach Links, 2018Co-Authors: Mingwei Yang, Ivan B. DjordjevicAbstract:In this paper, the challenges and problems for the in-band and off-band Adaptive Coding will be studied. To provide the agile and fast in-band Adaptive Coding, the information of the channel is inserted as the preamble into the each frame. Pseudorandom noise is utilized as the preamble and it is distributed and updated by the SDN controller to the transmitters and the receivers. Deploying the parallel preamble mapping distributed by the SDN controller is not only for the channel synchronization and the clock recovery but also for serving the in-band Adaptive Coding. The proposed scheme for the cross-layer design of the centralized SDN controller for the Adaptive Coding system is demonstrated and discussed. The proposed Adaptive Coding system is implemented and tested in the 100Gbps DP-QPSK fiber-optics transmission system. The performances of the system with different codes and Adaptive scheme in the system are examined and plotted. Also, the time-domain analysis for the LDPCs changing is performed to demonstrate its operational features based on the different channel conditions signal-to-noise ratio (SNR). By deploying the pseudonoise preamble detection, the system enables the rapidly in-band Adaptive Coding service with low overhead and short guard time. The cross-layer SDN controlling scheme, for updating the mapping between preamble and codes, provides the agile and robust service in the fiber-optics network.
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Adaptive modulation and Coding for free space optical channels
IEEE\ OSA Journal of Optical Communications and Networking, 2010Co-Authors: Ivan B. DjordjevicAbstract:Adaptive modulation and Coding can provide robust and spectrally efficient transmission over terrestrial free-space optical channels. Three Adaptive modulation schemes are considered in this paper: (i) variable-rate variable-power adaptation, (ii) channel inversion, and (iii) truncated channel inversion schemes. It is shown that a simple channel inversion scheme performs comparable to a variable-rate variable-power adaptation scheme in the weak turbulence regime but faces significant performance degradation in the strong turbulence regime. We further study Adaptive Coding based on large-girth quasi-cyclic low-density parity-check- (LDPC-) coded modulation. It is shown by simulation that deep fades of the order of 30 dB and above in the regime of strong turbulence can be tolerated with the proposed scheme. It is demonstrated that communication in the saturation regime is possible with the proposed Adaptive LDPC-coded modulation. We also determine the spectral efficiencies for the proposed Adaptive modulation and Adaptive Coding schemes.
Peng Guo - One of the best experts on this subject based on the ideXlab platform.
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Enhancing ZigBee throughput under WiFi interference using real-time Adaptive Coding
Proceedings - IEEE INFOCOM, 2014Co-Authors: Peng Guo, Jiannong Cao, Kui Zhang, Xuefeng LiuAbstract:Co-existing in the unlicensed ISM band, ZigBee transmissions can be significantly interfered by WiFi. Although several approaches recently are proposed to enable ZigBee transmission under WiFi interference, the ZigBee throughput still decreases to zero when WiFi throughput (generated by D-ITG) is over 8Mbps. In this paper, we propose a real-time (<; 5ms) Adaptive transmission (RAT) scheme to efficiently adapt forward error-correction Coding (FEC) on ZigBee devices in dynamic WiFi environment. We find that sizes of WiFi frames well follow the power law distribution model. With the model, corruption in ZigBee packets can be estimated to some extent, thus facilitating ZigBee device to choose a suitable FEC Coding to maximize the throughput. Extensive experimental results show that, compared with existing works, RAT achieves significant performance improvement of ZigBee transmissions in WiFi environment with different traffic load. Particularly, the ZigBee throughput of RAT can be about 10kbps when the WiFi throughput is 8Mbps.
Kui Zhang - One of the best experts on this subject based on the ideXlab platform.
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enhancing zigbee throughput under wifi interference using real time Adaptive Coding
International Conference on Computer Communications, 2014Co-Authors: Kui ZhangAbstract:33rd IEEE Conference on Computer Communications, IEEE INFOCOM 2014, Toronto, ON, 27 April-2 May 2014
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Enhancing ZigBee throughput under WiFi interference using real-time Adaptive Coding
Proceedings - IEEE INFOCOM, 2014Co-Authors: Peng Guo, Jiannong Cao, Kui Zhang, Xuefeng LiuAbstract:Co-existing in the unlicensed ISM band, ZigBee transmissions can be significantly interfered by WiFi. Although several approaches recently are proposed to enable ZigBee transmission under WiFi interference, the ZigBee throughput still decreases to zero when WiFi throughput (generated by D-ITG) is over 8Mbps. In this paper, we propose a real-time (<; 5ms) Adaptive transmission (RAT) scheme to efficiently adapt forward error-correction Coding (FEC) on ZigBee devices in dynamic WiFi environment. We find that sizes of WiFi frames well follow the power law distribution model. With the model, corruption in ZigBee packets can be estimated to some extent, thus facilitating ZigBee device to choose a suitable FEC Coding to maximize the throughput. Extensive experimental results show that, compared with existing works, RAT achieves significant performance improvement of ZigBee transmissions in WiFi environment with different traffic load. Particularly, the ZigBee throughput of RAT can be about 10kbps when the WiFi throughput is 8Mbps.
Rita Rinaldo - One of the best experts on this subject based on the ideXlab platform.
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Adaptive Coding and modulation for satellite broadband networks from theory to practice
International Journal of Satellite Communications and Networking, 2009Co-Authors: Hermann Bischl, Riccardo De Gaudenzi, Rita Rinaldo, Hartmut Brandt, Tomaso De Cola, Ernst Eberlein, Nicolas Girault, Eric Alberty, Stefan Lipp, Bjarne RislowAbstract:This paper presents the detailed design and the key system performance results of a comprehensive laboratory demonstrator for a broadband Ka-band multi-beam satellite system exploiting the new DVB-S2 standard with Adaptive Coding and modulation (ACM). This complete demonstrator allows in-depth verification and optimization of the ACM techniques applied to large satellite broadband networks, as well as complementing and confirming the more theoretical or simulation-based findings published so far. It is demonstrated that few ACM configurations (in terms of modulation and Coding) are able to efficiently cope with a typical Ka-band multi-beam satellite system with negligible capacity loss. It is also demonstrated that the exploitation of ACM thresholds with hysteresis represents the most reliable way to adapt the physical layer configuration to the spatial and time variability of the channel conditions while avoiding too many physical layer configuration changes. Simple ACM adaptation techniques, readily implementable over large-scale networks, are shown to perform very well, fulfilling the target packet-error rate requirements even in the presence of deep fading conditions. The impact of carrier phase noise and satellite nonlinearity has also been measured. Copyright © 2009 John Wiley & Sons, Ltd.
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channel estimation and physical layer adaptation techniques for satellite networks exploiting Adaptive Coding and modulation
International Journal of Satellite Communications and Networking, 2008Co-Authors: Stefano Cioni, Riccardo De Gaudenzi, Rita RinaldoAbstract:The exploitation of Adaptive Coding and modulation techniques for broadband multi-beam satellite communication networks operating at Ka-band and above has been shown to theoretically provide large system capacity gains. In this paper, the problem of how to accurately estimate the time-variant channel and how to adapt the physical layer taking into account the effects of estimator errors and (large) satellite propagation delays is analyzed, and practical solutions for both the forward and the reverse link are proposed. A novel pragmatic solution to the reverse link physical layer channel estimation in the presence of time-variant bursty interference has been devised. Physical layer adaptation algorithms jointly with design rules for hysteresis thresholds have been analytically derived. The imperfect physical layer channel estimation impact on the overall system capacity has been finally derived by means of an original semi-analytical approach. Through comprehensive system simulations for a realistic system study case, it is showed that the devised adaptation algorithms are able to successfully track critical Ka-band fading time series with a limited impact on the system capacity while satisfying the link outage probability requirement. Copyright © 2008 John Wiley & Sons, Ltd.
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Adaptive Coding and modulation for the dvb s2 standard interactive applications capacity assessment and key system issues
IEEE Wireless Communications, 2007Co-Authors: Eric Alberty, Rita Rinaldo, S Defever, Cyrille Moreau, R De Gaudenzi, S Ginesi, G Gallinaro, A VernucciAbstract:Point-to-point multibeam satellite systems based on the DVB-S standard are currently designed for link closure in the worst-case propagation and location conditions. The DVB-S standard, conceived for broadcasting applications, considers a fixed Coding rate and modulation format that are selected according to the assumed coverage and availability requirements. This approach implies the occurrence of high margins in the majority of the cases, when interference and propagation conditions allow for higher signal-to-noise-plus-interference ratio. The Adaptive Coding and modulation (ACM) introduction in the new DVB-S2 standard for the interactive service profile opens up a number of appealing opportunities for the design and development of satellite broadband networks. In this article we show how the ACM introduction in the satellite downlink enables greatly enhanced system performance but also has a profound impact on the way the system and some of the key system components are designed.
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capacity analysis and system optimization for the forward link of multi beam satellite broadband systems exploiting Adaptive Coding and modulation
International Journal of Satellite Communications and Networking, 2004Co-Authors: Rita Rinaldo, Riccardo De GaudenziAbstract:This paper deals with the system capacity analysis and assessment of the potential advantages provided by the introduction of Adaptive Coding and Modulation (ACM) in the reverse link of multi-beam broadband satellite systems. ACM is intended to increase the system throughput for a given terminal EIRP power by optimizing the individual links physical layer to the current channel conditions. The physical layer adaptation will be driven by the inbound demodulator signal over noise plus interference ratio (SNIR) estimation. A general methodology for ACM physical layer optimization based on the system capacity maximization is also illustrated. A theoretical analysis of ACM systems capacity is performed for both time division multiple access (TDMA) and code division multiple access (CDMA) schemes. As the exact analytical capacity computation results to be very complex while Monte Carlo approach leads to very time consuming simulations, a simplified semi-analytic approach is devised. Numerical results showing the huge improvement in terms of capacity by the ACM adoption are obtained for both the semi-analytic and the Monte Carlo approaches in a realistic study case corresponding to a Ka-band multibeam satellite system. A good match between the two approaches is also demonstrated. Copyright © 2004 John Wiley & Sons, Ltd.
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Adaptive Coding and Modulation for Next Generation Broadband Multimedia Systems
20th AIAA International Communication Satellite Systems Conference and Exhibit, 2002Co-Authors: Riccardo De Gaudenzi, Rita RinaldoAbstract:This paper investigates the potential advantages provided by Adaptive Coding and modulation (ACM) for next generation broadband satellite communication systems operating at Ka-band and above. The problem tackled in the manuscript is how to find an optimal physical layer structure able to efficiently support packet type of traffic and to adapt to the varying propagation channel conditions and location dependent signal-tointerference plus noise ratio (SNIR). In particular, the physical layer and key system parameters optimization problem (i.e. Coding rate, modulation order, spreading factor, frequency and polarization reuse factors) is tackled for the general case of the downlink of a multibeam satellite system. Eventually, the average system capacity and bit rate distribution for the proposed Adaptive coded modulation scheme is derived in a realistic scenario with different frequency reuse factors. The resulting large capacity advantage with respect to solutions currently envisioned for satellite multimedia systems is proved.