This paper considers a multi-antenna transmission strategy for high speed railway communications. In order to achieve better performance than conventional space-frequency block coding schemes, we propose a directional...
This paper considers a multi-antenna transmission strategy for high speed railway communications. In order to achieve better performance than conventional space-frequency block coding schemes, we propose a directional beamforming strategy for the High-speed railway (HSR) communication by exploiting some characteristic of the railway system including predetermined moving tracks and real-time positioning information. Moreover, for alleviating the effect of Doppler shift due to the moving train, a frequency offset precorrection method is also incorporated with direction beamforming. Theoretical Signal-to-noise ratio (SNR) gain of the proposed beamforming scheme over traditional HSR communication schemes is also derived for illustrating the performance enhancement. Numerical results verify the effectiveness of our proposed scheme even with some kind of imperfect position information availab.e at the transmitter.
In existing metro systems,the train ground radio communication system for different applications are deployed *** and constructing the communication infrastructures repeatedly wastes substantial social resources,and i...
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In existing metro systems,the train ground radio communication system for different applications are deployed *** and constructing the communication infrastructures repeatedly wastes substantial social resources,and it brings difficulties to maintain all these *** present the communication Quality of service(Qo S) requirement for different train ground radio *** integrated TD-LTE based train ground radio communication system for the metro system(LTE-M) is designed *** order to test the LTEM system performance,an indoor testing environment is set *** channel simulator and programmable attenuators are used to simulate the real metro *** test results show that the designed LTE-M system performance satisfies metro communication requirements.
This paper considers a multi-antenna transmission strategy for high speed railway communications. In order to achieve better performance than conventional space-frequency block coding schemes, we propose a directional...
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This paper considers a multi-antenna transmission strategy for high speed railway communications. In order to achieve better performance than conventional space-frequency block coding schemes, we propose a directional beamforming strategy for the High-speed railway(HSR) communication by exploiting some characteristic of the railway system including predetermined moving tracks and real-time positioning information. Moreover,for alleviating the effect of Doppler shift due to the moving train, a frequency offset precorrection method is also incorporated with direction beamforming. Theoretical Signalto-noise ratio(SNR) gain of the proposed beamforming scheme over traditional HSR communication schemes is also derived for illustrating the performance *** results verify the effectiveness of our proposed scheme even with some kind of imperfect position information availab.e at the transmitter.
This paper proposes a method to design a robust reinforcement learning-based tracking control scheme for the wheeled mobile robot. A policy iteration algorithm and a neural network are used to design an adaptive criti...
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According to the standard for the GSM for railway(GSM-R) wireless systems in China train controlsystem level 3(CTCS-3),the control data transfer delay should be no larger than 500 ms with greater than99% *** of both ...
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According to the standard for the GSM for railway(GSM-R) wireless systems in China train controlsystem level 3(CTCS-3),the control data transfer delay should be no larger than 500 ms with greater than99% *** of both non-redundant networks and intercross redundant networks and cases of single Mobile terminals(MTs) and redundant MTs on one train are considered,and the corresponding vehicle-ground communication models,delay models,and fault models are *** simulation results confirm that the transfer delay can meet the standard requirements under all *** particular,the probability is greater than 99.996% for redundant MTs and networks,and the standard of transfer delay in CTCS-3 will be improved inevitably.
In this paper, we focus on the problem of community detection on TSina: the most popular microblogging network in China. By characterizing the structure and content of microgroup (community) on TSina in detail, we rev...
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ISBN:
(纸本)9783642258558
In this paper, we focus on the problem of community detection on TSina: the most popular microblogging network in China. By characterizing the structure and content of microgroup (community) on TSina in detail, we reveal that different from ordinary social networks, the degree assortativity coefficients are negative on most microgroups. In addition, we find that users from the same rnicrogroup likely exhibit some similar attributes (e.g., sharing many followers, tags and topics). Inspired by these new findings, we propose a united method for microgroup detection without losing the information of link structure and user attribute. First, the link direction is converted to the weight by giving higher value to the more surprising link, while attribute similarity between two users is measured by the Jaccard coefficient of common features like followers, tags, and topics. Then, above two factors are uniformly converted to the edge weight of a newly generated network. Finally, many frequently used community detection algorithms that support weighted network would be employed. Extensive experiments on real social networks show that the factors of link structure and user attribute play almost equally important roles in microgroup detection on TSina.. Our newly proposed method significantly outperforms the traditional methods with average accuracy being improved by 25%, and the number of unrecognized users decreasing by about 75%.
Unmanned surface vehicles (USV) has become popular around the world with their capabilities in complicated and low-cost applications, also reduce the danger to humans especially in the environmental field. The environ...
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Environmental monitoring plays a very important role in the activities of predicting and protecting environments and society. The activities are included of monitoring environmental parameters continuously, predicting...
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This paper discusses an approach to automated evaluation of multi-document summarization by computing the similarities of automated summaries and human summaries and scoring the automated summaries by their similariti...
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Frequency synthesizer plays an important role in frequency hopping communication system. In this paper, we derivate the conditions for a system to become the chaotic based on the phase model of phase-locked synthesize...
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