Real-time applications such as video and audio streaming popularly in the public network require the guarantee of Quality of Services(QoS). But most of the current QoS routing optimization algorithm such as Ant Colony...
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In this paper, a Distortion-guaranteed Energy Saving (D GES) power allocation scheme is proposed for multiuser video transmission. The multiuser downlink Orthogonal Frequency-division Multiple-access (OFDMA) system is...
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The measurement and analysis of wideband mobile channel are the foundations of network coverage and wireless network optimization. An outdoor propagation measurement campaign in which the sounding signal is PN sequenc...
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The measurement and analysis of wideband mobile channel are the foundations of network coverage and wireless network optimization. An outdoor propagation measurement campaign in which the sounding signal is PN sequence at 2.6GHz has been performed in beijing recently, and the result shows that slippage correlation based on PN sequence is capable to probe the channel impulse response (CIR). However, considering the inter-path interference that affects the result, an amplitude distortion correction algorithm is proposed to eliminate inter-path interference and enhance the accuracy of channel parameters. Moreover, results including the effect of the correction algorithm are analyzed and compared with that of traditional algorithm.
The increasing interest that has been drawn to wireless sensor network technology is therefore required measurement and analysis of wideband mobile channel with near ground antennas. Using slippage correlation algorit...
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The increasing interest that has been drawn to wireless sensor network technology is therefore required measurement and analysis of wideband mobile channel with near ground antennas. Using slippage correlation algorithm, nine typical indoor and outdoor scenarios were analyzed to compare the system performance in 2.28-2.32GHz, with antenna elevation and scenario as only variables. Both large and small-scale characteristics, such as channel impulse response, power delay profile, path loss exponent and shadowing parameter are extracted, evaluated and reported. The relationship between channel attenuation and antenna elevation, as well as the specific impact on fading channel behaviors by different measurement scenarios are concluded.
In this paper, a Best-M feedback scheme using Kalman filter is proposed to reduce the uplink feedback overhead in the presence of feedback delay. Best-M feedback scheme is an effective method to reduce the number of t...
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ISBN:
(纸本)9781849194709
In this paper, a Best-M feedback scheme using Kalman filter is proposed to reduce the uplink feedback overhead in the presence of feedback delay. Best-M feedback scheme is an effective method to reduce the number of the channel quality information (CQI) feedback. However, the CQI feedback after the conventional Best-M decision is inaccurate for base station (BS) scheduling due to the feedback delay and the time varying nature of the channel. A modified limited feedback scheme is proposed to use a Kalman filter to compensate for the performance degradation caused by the feedback delay in Best-M feedback scheme. In the proposed scheme, the user equipment (UE) exploits a Kalman filter to predict the signal to interference plus noise ratio (SINR). Then, the UE makes the Best-M decision based on this predicted SINR and sends the corresponding CQI back to the BS. The simulation results show that the Best-M feedback scheme using Kalman filter, which achieves the same feedback reduction as the conventional scheme, improves the system spectral efficiency.
60GHz millimeter wave communication systems usually use directional beamforming to compensate high propagation loss in this band. To fully exploit its potential of spatial reuse owing to directivity, an interference a...
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ISBN:
(纸本)9781467318808
60GHz millimeter wave communication systems usually use directional beamforming to compensate high propagation loss in this band. To fully exploit its potential of spatial reuse owing to directivity, an interference alignment scheme based on subarray partition is proposed in this paper. In this scheme, the whole antenna array is partitioned into M subarrays, where beamforming is performed within each subarray, and interference alignment is implemented among M subarray pairs. Simulation results have shown that the proposed scheme can further mitigate the interference on the basis of inner-subarray beamforming, and significantly improve the sum-capacity of the network in high transmit SNR region.
In this paper, we implement a prototype of smart-home system based on the IPv6 over Low power Wireless Personal Area networks, 6LoWPAN. The seamless connection is built between the wireless sensor networks (WSNs) and ...
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In this paper, we implement a prototype of smart-home system based on the IPv6 over Low power Wireless Personal Area networks, 6LoWPAN. The seamless connection is built between the wireless sensor networks (WSNs) and the Internet, which makes users visit the smart-home system through other IP-based networks. We also implement a routing protocol based on AODV-jr and embed it into 6LoWPAN. Imote2 platforms are used to verify our system. Meanwhile, this system provides a user-friendly interface to monitor and control the whole system by using web service technology. Furthermore, the system can be deployed easily and experimental results show that the design of our smart-home system can be served timely and reliably.
In recent years, with the rapid evolution of the next generation network (NGN), next generation service (NGS) has been proposed almost at the same time. In the coming NGN era, end users have more and more requirements...
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In recent years, with the rapid evolution of the next generation network (NGN), next generation service (NGS) has been proposed almost at the same time. In the coming NGN era, end users have more and more requirements for NGS. They desire not only the service can be accessed anywhere and anytime, but also the service is personalized to adapt to their different devices, heterogeneous networks and their contexts about activities and locations. This paper proposes a creation approach of user centric service session basing on the Virtual Private Service network (VPSN) model to ensure the service personalization. It also tries to guarantee the quality of the service according to the different environment by context-aware management. In the end, the paper introduces a new idea to define the service performance and finish the paper with a conclusion and perspective.
This paper addresses the cross-tier interference issue in two-tier OFDMA femtocell networks using hybrid spectrum allocation. Firstly, we propose a classification method for users. The macro users are classified into ...
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ISBN:
(纸本)9781467318808
This paper addresses the cross-tier interference issue in two-tier OFDMA femtocell networks using hybrid spectrum allocation. Firstly, we propose a classification method for users. The macro users are classified into several categories based on their geographic location, and femto users are classified according to the categories of macro users. Then, based on such user classifications, a hybrid spectrum allocation (HSA) scheme is proposed. HSA employs a dynamic orthogonal spectrum allocation for macro user categories according to the number of MUEs in two-tier networks, and fractional spectrum reuse for femto user categories based on their different communication environments. Simulation results show that the proposed scheme can improve outage and throughput performance of macro users with less impact on femto users.
Multimedia computing has caused increasing resource consumption and computational overhead. This article pays its considerable attention to cloud computing in handling multimedia applications and services effectively ...
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Multimedia computing has caused increasing resource consumption and computational overhead. This article pays its considerable attention to cloud computing in handling multimedia applications and services effectively and efficiently. First, we present a solution to reconstruct the networkarchitecture of multimedia field based on cloud computing to integrate multi-service platforms for the heterogeneous terminals. Then we deploy a Sub-cloud computing platform with the central-control type of Sub-cloud architecture, the distributed way to save data in the Sub-cloud and the cloud proxy server setting on the edge of Sub-cloud, to satisfy the various QoS demands of the services. Finally, Sub-cloud platform is presented, and 3D shading map on mobile phone is adopted as case studies to demonstrate the feasibility and high efficiency of the proposed Sub-cloud design.
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