This paper proposes a methodology for designing and optimizing the performance of adaptive coding and modulation (ACM) schemes for the forward link of unicast satellite broadband networks. The proposed technique of ge...
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This paper proposes a methodology for designing and optimizing the performance of adaptive coding and modulation (ACM) schemes for the forward link of unicast satellite broadband networks. The proposed technique of general applicability is based on the overall system capacity maximization conditioned on meeting a certain service area coverage for a given outage probability. The paper first derives in detail the method for computing the Shannon-based capacity of a multi-beam satellite system adopting ACM. Then the link efficiency is optimized under different physical layer constraints allowing a more realistic system performance assessment. Finally, to exemplify the methodology application and to quantify the ACM system performance improvement capabilities a study case corresponding to a Ka-band state-of-the-art bent pipe satellite network is provided. The example illustrates the very substantial capacity gain offered by state-of-the-art adaptivemodulation and coding schemes utilization compared to current broadband satellite system design approach. Copyright (C) 2004 John Wiley Sons, Ltd.
The paper discusses cross-layer issues of DVB-S2 networks with adaptive coding and modulation (ACM) on the physical layer forward link. Also future return channel via satellite (RCS) systems employing adaptive schemes...
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The paper discusses cross-layer issues of DVB-S2 networks with adaptive coding and modulation (ACM) on the physical layer forward link. Also future return channel via satellite (RCS) systems employing adaptive schemes on the return link are analysed. Cross-layer issues focus on medium access control (MAC) and encapsulation layer effects. Recent work of the S2 encapsulation over generic streams (GS) is described, and the effects on quality of service (QoS) scheduling for the forward link are analysed by means of simulation. A performance comparison between DVB-S and S2, both for transport streams (TS) and GS shows a significant gain by new encapsulation and fragmentation protocols that allow fragmentation across BBFrames. Here, realistic traffic scenarios with a mix of several services as well as rain fading are taken into account. For the return link, an adaptive scheme is discussed, going beyond the current RCS standard. Several approaches for access burst structures are presented and their impact on link efficiency through padding and encapsulation overhead is simulated. Finally, burst segmentation impact on jitter is investigated. Copyright (c) 2006 John Wiley & Sons, Ltd.
This paper deals with the design, evaluation and performance comparison of smart framing strategies that complement the packet scheduler in DVB-S2 systems with adaptive coding and modulation. Provided that user data p...
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ISBN:
(纸本)9781424403561
This paper deals with the design, evaluation and performance comparison of smart framing strategies that complement the packet scheduler in DVB-S2 systems with adaptive coding and modulation. Provided that user data packets are transmitted grouped in frames, each of them using a modulation and coding setting (ModCod), the inherent spectral efficiency of the selected ModCod can be cancelled by a poor framing efficiency, i.e. transmitting frames with large padding component. For this reason, smart framing strategies are proposed in this paper, which optimize the framing efficiency.
The paper discusses cross-layer issues of DVB-S2 networks with adaptive coding and modulation (ACM) on the physical layer forward link. Also future return channel via satellite (RCS) systems employing adaptive schemes...
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The paper discusses cross-layer issues of DVB-S2 networks with adaptive coding and modulation (ACM) on the physical layer forward link. Also future return channel via satellite (RCS) systems employing adaptive schemes on the return link are analysed. Cross-layer issues focus on medium access control (MAC) and encapsulation layer effects. Recent work of the S2 encapsulation over generic streams (GS) is described, and the effects on quality of service (QoS) scheduling for the forward link are analysed by means of simulation. A performance comparison between DVB-S and S2, both for transport streams (TS) and GS shows a significant gain by new encapsulation and fragmentation protocols that allow fragmentation across BBFrames. Here, realistic traffic scenarios with a mix of several services as well as rain fading are taken into account. For the return link, an adaptive scheme is discussed, going beyond the current RCS standard. Several approaches for access burst structures are presented and their impact on link efficiency through padding and encapsulation overhead is simulated. Finally, burst segmentation impact on jitter is investigated. Copyright (c) 2006 John Wiley & Sons, Ltd.
This paper presents a novel solution optimizing satellite access lower layers and system performances called variable size packets (VSPs) designed for the transport of Internet protocol (IP) datagrams or any packet ty...
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This paper presents a novel solution optimizing satellite access lower layers and system performances called variable size packets (VSPs) designed for the transport of Internet protocol (IP) datagrams or any packet type from the network layers characterized by a highly variable size. VSP objective is to maximize the, efficiency of layers 1 and 2 thrbugh a joint optimization of access and transport mechanisms mainly for satellite systems addressing residential or corporate terminals market through a multiple-access scheme. It, is particularly attractive for, the return link of next-generation satellite systems to be IP-based, as a possible evolution of the digital video broadcast-return channel via satellite (DVB-RCS) standard. The VSP solution relies on the definition of multiple encapsulation sizes, and is associated to a waveform and an access adapted to variable size packets' transport. It uses the traffic's variable size nature to increase encapsulation efficiency, coding, and spectral,efficiency performances, and system flexibility. It is well adapted to systems using an adaptive waveform leading to system capacity's increase and better performances. This paper describes the VSP principle, advantages and possible high-level system tradeoffs. It then focuses on one critical issue, the, coding, and presents a suitable coding scheme's choice with regards to performances and implementation complexity.
This paper introduces two alternative layered-coding (LC) structures suitable for a combination of a geostationary (GEO) satellite and a terrestrial system providing multicasting multimedia services. Both schemes incl...
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This paper introduces two alternative layered-coding (LC) structures suitable for a combination of a geostationary (GEO) satellite and a terrestrial system providing multicasting multimedia services. Both schemes include a RAKE receiver and their performance results are presented under realistic satellite and terrestrial channel conditions. The structures are based on mapping the coded bits either onto 8-PSK symbols or onto QPSK symbols. The LC parameters (such as the interleaver design and the convolutional encoder structures) are analysed and their effect on performance is quantified, especially in cases of highly correlated channels (low vehicular speeds). The various impairments that are associated to the transmission through both terrestrial and satellite correlated fading channels will be taken into account and link level performance results as well as a complexity discussion will be presented. Copyright (C) 2004 John Wiley Sons, Ltd.
Link adaptation techniques, such as power control and adaptive coding and modulation, aim at maximizing the throughput in wireless networks while maintaining the signal quality in terms of the signal to interference r...
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ISBN:
(纸本)0780379543
Link adaptation techniques, such as power control and adaptive coding and modulation, aim at maximizing the throughput in wireless networks while maintaining the signal quality in terms of the signal to interference ratio. However, fair resource allocation among different users must be taken into consideration, particularly in fixed broadband wireless access networks. The low/no mobility of users in such networks can lead to location-dependent resource utilization, which causes a significant variation in the performance from a user to another. For instance, adaptive coding and modulation schemes increase the aggregate throughput in the network;however, they also increase the variation of the throughput among users. In this paper, we propose, and analyze the performance of, three fairness enhancement schemes that can be integrated with link adaptation techniques. Results show that the three proposed scheme can enhance the fairness of link adaptation techniques with different degrees without causing (or with minor) degradation to the total network throughput.
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