Beijing University Of Posts And Telecommunications Research Articles

Reference-frame-independent quantum key distribution of wavelength division multiplexing with multiple quantum channels* *Project supported by the Fundamental Research Funds for the Central Universities, China (Grant No. 2019XD-A02), the State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (BUPT) (Grant No. IPOC2021ZT10), and BUPT Innovation and Entrepreneurship Support Program (Grant No. 2021-YC-A315).

Reference-frame-independent quantum key distribution (RFI-QKD) can allow a quantum key distribution system to obtain the ideal key rate and transmission distance without reference system calibration, which has attracted much attention. Here, we propose an RFI-QKD protocol based on wavelength division multiplexing (WDM) considering finite-key analysis and crosstalk. The finite-key bound for RFI-QKD with decoy states is derived under the crosstalk of WDM. The resulting secret key rate of RFI-QKD, which is more rigorous, is obtained. Simulation results reveal that the secret key rate of RFI-QKD based on WDM is affected by the multiplexing channel number, as well as crosstalk between adjacent channels.

Polarization dependence of gain and amplified spontaneous Brillouin scattering noise analysis for fiber Brillouin amplifier**Project supported by the National Natural Science Foundation of China (Grant Nos. 61531003, 61690195, 61701040, and 61427813), the Fund of State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications (BUPT), China, and the Youth Research and Innovation Program of BUPT,

The polarization dependences of gain and amplified spontaneous Brillouin scattering (ABS) noise for fiber Brillouin amplifier (FBA) are analyzed through theories, simulations, and experiments. Modified vector propagation equations for calculating the gain of the probe signal and the ABS noise are derived and analyzed in the Stokes spaces. In simulations and experiments, we prove that the gain of the probe signal and the ABS noise are strongly dependent on the relative state of polarization (SOP) of the pump and probe signals. The closer the relative SOP of the pump and probe signals is, the more obvious ABS noise suppression effect will be brought by increasing the power of the input probe signal.

Marketing Promotion Feasibility of College Students' Innovation Projects

Nowadays, Students' Innovation Projects are very popular in most colleges. However, only few can be launched into the market. In this essay, the marketing promotion of college students' innovation projects was discussed in order to improve the fairness and efficiency of the selection of innovation projects. 100 innovative project data were selected as a sample, which is from Beijing University of Posts and Telecommunications (BUPT) in 2015. The evaluation indexes were obtained by the method of investigation and research. Then the AHP method was used to get the weight of each index according to the relative importance of the indexes. For the calculation of the final weight, the method of combining the subjective and objective, that is, at the same time the Entropy Method was used to determine the weight of each index. Finally, the project evaluation was done using the evaluation method they have proposed. There is a strong positive correlation between their evaluation results and the results of experts. As a result, the validity of evaluation method has been successfully proved.

Evolution of Limited-Feedback CoMP Systems from 4G to 5G: CoMP Features and Limited-Feedback Approaches

Coordinated multipoint (CoMP) transmission/reception has been adopted as a key technology to alleviate the intercell interference (ICI) in fourthgeneration (4G) mobile communication. This article reviews the state of the art in limited-feedback CoMP systems research. We first give an overview of recent related work in feedback-based coordinated transmission and then provide a performance analysis of typical feedback schemes and sensitivity to the channel state information (CSI) delay. To back up the discussion, we have validated the benefits of CoMP using field-test results from a CoMP trial network built at the Beijing University of Posts and Telecommunications (BUPT) campus. Furthermore, since mobile systems evolving to fifth generation (5G) have to bear a huge quantity of irregularly distributed wireless data traffic, cooperative communication will be more widely applied not only to address the ICI but also to improve the system resource utilization and data rate. We summarize the recent trend on 5G network architectures enabling the novel CoMP features, and we discuss the potential evolution directions of limited-feedback approaches motivated by CoMP development toward future 5G networks.

Advanced MIMO Techniques in the Heterogeneous Networks

1 Beijing Key Lab of New Generation Broadband Wireless Mobile Communication Technology, Standard and Verification, China Academy of Telecommunication Research of MIIT (CATR), Beijing 100191, China 2 Faculty Development Center, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, China 3 School of Telecommunications and Information Engineering, Xi’an University of Posts and Telecommunications, Xi’an 710121, China 4The Communications Group, Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK 5McGill University, 3480 Rue University, Montreal, Canada H3A 0E9

Internet quality abnormal analysis with k-means clustering

The anomaly detection using data mining techniques has widely aroused interests in recent years. This paper proposes a novel algorithm to do the Internet quality abnormal analysis. The algorithm is developed with k-means clustering method to analyze the real-time data of Internet quality acquired at the testbed of Beijing University of Posts and Telecommunications (BUPT) for the first time. The main objective of this paper is to construct a statistical Internet quality abnormal analysis system capable of classifying the Internet quality data as normal or abnormal. For this purpose the algorithm constructs a model in training process. The data of Internet quality are compared with the model and data with distinct deviation from the model is marked as abnormal. The algorithm can split the abnormal data which are applied as a guide to further investigation of Internet anomaly root cause. And the result proved to be credible, which will be useful for the network administrators to manage the network.

Exploring Cultural Knowledge in EFL Teaching in an EAVSC

Teaching cultural knowledge of the target language has been an ever-increasing focus in English as a foreign language (EFL) teaching in China during the last two decades. Apart from cultivating students’ four basic skills, more and more attention has been paid to the enhancement of their cross-cultural competence. To achieve the goal, EFL teachers and researchers have been exploring both reasonable theoretical frameworks and effective practical measures. This paper aims to analyze a way of teaching cultural knowledge based on an English audio-video speaking course (EAVSC) at Beijing University of Posts and Telecommunications (BUPT). It presents the specific teaching modal from five aspects: the teaching material, the teaching context, the teaching principles and approach, students’ speaking activities (both in-class and off-class speaking tasks), and the method to evaluate students’ achievement. Through such a systematic organization and arrangement, this case study proves to be an effective way of cultural teaching.

LTE/LTE‐Advanced Cellular Communication Networks

1Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4 2Centre for Wireless Network Design, University of Bedfordshire, Bedfordshire LU1 3JU, UK 3NSN Research, Nokia Siemens Networks, 02610 Espoo, Finland 4Key Laboratory of Universal Wireless Communication, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, China

An Integrated Quasi-optical Analysis Method and Its Experimental Verification

This paper gives an overview on the design and analysis technique for quasi-optical systems developed at Queen Mary, University of London and Beijing University of Posts and Telecommunications (BUPT) in collaboration with Beihang University. The design and analysis technique in question is an integration of two numerical methods. One applies Gaussian beam mode analysis to transport signal beams between focusing reflectors while accounting for diffractive processes, the other computes the emergent beam fields of either transmission and/or reflection for signal conditioning components interleaved between reflectors. A three dimensional visual software is developed based on the integrated method. The paper also presents the experimental verification of this design and analysis technique based on a dual-path quasi-optical network.

IIN model: modifications and case study

Referring to IN/Internet interworking models proposed by International Telecommunication Union and Telecommunication standardization sector (ITU-T) and the Internet Engineering Task Force (IETF), a new model is proposed based on the China Mobile Intelligent Network version 02 (CMIN02) system from Beijing University of Posts and Telecommunications (BUPT). This model adds modifications and refinements to the former two reference models. This model can be divided into three layers horizontally and three sections vertically. Emphasis is put on the gateways due to their importance. Moreover, a novel notion called information flow trail is proposed, which is helpful in designing complex gateways. So far, most work on gateways focuses on studying simple cases where gateways have only two interfaces towards the outside. However, Management Gateway Function (MGF), Service Control Gateway Function (SCGF) and Call/Bearer Gateway Function (C/BGF) have more than two interfaces. In this case, the novel notion is quite helpful. During the implementation of Project 863 the modified model has been tested and proved viable.