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LANDMARC Localization Algorithm Based on Weight Optimization

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Chinese Journal of Electronics 2018年第6期27卷 1291-1296页

作者： HU Bing PENG Huijun SUN Zhixin key laboratory of broadband wireless communication and sensor network technology Ministry of EducationNanjing University of Posts and Telecommunications

In order to solve the problem that the difference of Received signal strength(RSS) between tags will become large when tags are close to the reader, which exists in LANDMARC system, a LANDMARC localization algorithm based on weight optimization is proposed in the paper. We optimize the weight by redefining the formulas of in-weight and ex-weight. In-weight formula is discussed under the free space propagation model. The definition of ex-weight is obtained by analyzing the relationship between RSS and distance under the log-distance path loss model. We evaluate the performance of the proposed algorithm and compare it with the algorithm based on normalized weight. The simulation results show the superior performance of the proposed algorithm in terms of location accuracy.

关键词： Location identification based on dynamic active RFID calibration(LANDMARC) system Radio frequency identification(RFID) Indoor localization Weight optimization

Cross-layer resource allocation based on equivalent bandwidth in OFDMA systems

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Journal of Systems Engineering and Electronics 2016年第4期27卷 754-762页

作者： Su Pan Cheng Li Sheng Zhang Danwei Chen key Lab of broadband wireless communication and sensor network technology Nanjing University of Posts & Telecommunications

A quality of service（QoS） guaranteed cross-layer resource allocation algorithm with physical layer, medium access control（MAC） layer and call admission control（CAC） considered simultaneously is proposed for the full IP orthogonal frequency division multiple access（OFDMA） communication system, which can ensure the quality of multimedia services in full IP *** algorithm converts the physical layer resources such as subcarriers, transmission power, and the QoS metrics into equivalent bandwidth which can be distributed by the base station in all three layers. By this means, the QoS requirements in terms of bit error rate（BER）, transmission delay and dropping probability can be guaranteed by the cross-layer optimal equivalent bandwidth allocation. The numerical results show that the proposed algorithm has higher spectrum efficiency compared to the existing systems.

关键词： resource allocation equivalent bandwidth crosslayer optimization orthogonal frequency division multiple access(OFDMA)

Simplification of I-Vector Extraction for Speaker Identification

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Chinese Journal of Electronics 2016年第6期25卷 1121-1126页

作者： XU Longting YANG Zhen SUN Linhui broadband wireless communication and sensor network technology key Lab Nanjing University of Posts and Telecommunications

The identity vector(i-vector) approach has been the state-of-the-art for text-independent speaker recognition, both identification and verification in recent years. An i-vector is a low-dimensional vector in the socalled total variability space represented with a thin and tall rectangular matrix. This paper introduces a novel algorithm to improve the computational and memory requirements for the application. In our method, the series of symmetric matrices can be represented by diagonal expression,sharing the same dictionary, which to some extent is analogous to eigen decomposition, and we name this algorithm Eigen decomposition like factorization(EDLF). Similar algorithms are listed for comparison, in the same condition,our method shows no disadvantages in identification accuracy.

关键词： Speaker identification Closed-set I-vector Symmetric matrix factorization

Speech Signal Processing on Graphs: Graph Topology, Graph Frequency Analysis and Denoising

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Chinese Journal of Electronics 2020年第5期29卷 926-936页

作者： WANG Tingting GUO Haiyan LYU Bin YANG Zhen broadband wireless communication and sensor network technology key Lab Nanjing University of Posts and Telecommunications

The paper investigates the hidden relationships among speech samples by applying graph tools. Specifically, we first estimate an applicable graph topology for unstructured speech signals, which can map speech signals into the vertex domain successfully and construct as Speech graph signals(SGSs). On the basis, we define a new graph Fourier transform for SGSs, which can investigate its related graph Fourier analysis. Moreover,we propose a new Graph structure spectral subtraction(GSSS) method for speech enhancement under different noisy environments. Simulation results show that the performance of the GSSS method can be significantly improved than the classical Basic spectral subtraction(BSS) method in terms of the average Segmental signal-tonoise ratio(SSNR), Perceptual evaluation of speech quality(PESQ) and the computational complexity.

关键词： Graph signal processing Speech Graph Fourier transform Graph topology Denoising

Proportional Fairness-Based Energy-Efficient Power Allocation in Downlink MIMO-NOMA Systems with Statistical CSI

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China communications 2019年第12期16卷 47-55页

作者： Yonghai Lin Zhen Yang Haiyan Guo key laboratory of Ministry of Education in broadband wireless communication and sensor network technology Nanjing University of Posts and Telecommunications

In this paper, proportional fairness(PF)-based energy-efficient power allocation is studied for multiple-input multiple-output(MIMO) non-orthogonal multiple access(NOMA) systems. In our schemes, statistical channel state information(CSI) is utilized for perfect CSI is impossible to achieve in practice. PF is used to balance the transmission efficiency and user fairness. Energy efficiency(EE) is formulated under basic data rate requirements and maximum transmitting power constraints. Due to the non-convex nature of EE, a two-step algorithm is proposed to obtain sub-optimal solution with a low complexity. Firstly, power allocation is determined by golden section search for fixed power. Secondly total transmitting power is determined by fractional programming method in the feasible regions. Compared to the performance of MIMO-NOMA without PF constraint, fairness is obtained at expense of decreasing of EE.

关键词： MIMO-NOMA energy efficiency proportional fairness fractional programming method golden section search

Multimodal fusion recognition for digital twin

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Digital communications and networks 2024年第2期10卷 337-346页

作者： Tianzhe Zhou Xuguang Zhang Bing Kang Mingkai Chen key laboratory of broadband wireless communication and sensor network technology Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing210003China

The digital twin is the concept of transcending reality,which is the reverse feedback from the real physical space to the virtual digital *** hold great prospects for this emerging *** order to realize the upgrading of the digital twin industrial chain,it is urgent to introduce more modalities,such as vision,haptics,hearing and smell,into the virtual digital space,which assists physical entities and virtual objects in creating a closer ***,perceptual understanding and object recognition have become an urgent hot topic in the digital *** surface material classification schemes often achieve recognition through machine learning or deep learning in a single modality,ignoring the complementarity between multiple *** order to overcome this dilemma,we propose a multimodal fusion network in our article that combines two modalities,visual and haptic,for surface material *** the one hand,the network makes full use of the potential correlations between multiple modalities to deeply mine the modal semantics and complete the data *** the other hand,the network is extensible and can be used as a universal architecture to include more *** show that the constructed multimodal fusion network can achieve 99.42%classification accuracy while reducing complexity.

关键词： Digital twin Multimodal fusion Object recognition Deep learning Transfer learning

Fairness-oriented physical layer network coding in cooperative multiple access channels due to MRC and SIC

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The Journal of China Universities of Posts and Telecommunications 2012年第6期19卷 45-51页

作者： CHENG Yu-lun YANG Long-xiang Jiangsu key laboratory of wireless communications Nanjing University of Posts and Telecommunications key laboratory of broadband wireless communication and sensor network technology Nanjing University of Posts and Telecommunications

This paper investigates the impacts of network coding （NC） on user fairness from the network perspective in multiple access channels. Firstly, simultaneous outage is exploited as the metric to evaluate user fairness. To optimize it, a fairness-oriented physical layer NC scheme is proposed, in which users＇ signals are superimposed in specific calculated proportion at relay and then decoded by maximal ratio combination （MRC） and serial interference cancellation （SIC） at destination. Furthermore, the influence of power allocation coefficient error on simultaneous outage is also analyzed to reveal its correlation with user fairness. Simulation results indicate that the proposed scheme can supply approximately equal performance promotion for each cooperation-participated user and outperform those without fairness consideration in terms of the employed metric.

关键词： cooperative system user fairness simultaneous outage MRC SIC

Load Balanced Coding Aware Multipath Routing for wireless Mesh networks

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Chinese Journal of Electronics 2015年第1期24卷 8-12页

作者： SHAO Xing WANG Ruchuan HUANG Haiping SUN Lijuan College of Computer Nanjing University of Posts and Telecommunications College of Information Engneering Yancheng Institutue of Technology Jiangsu High technology Research key laboratory for wireless sensor networks key Lab of broadband wireless communication and sensor network technology

The growth of network coding opportunities is considered the unique optimization goal by most current network coding based routing algorithms for wireless mesh networks. This usually results in flows aggregation problem in areas with coding opportunities, and degrades the network performance. This paper proposes a Load balanced coding aware multipath routing(LCMR)for wireless mesh networks. To facilitate the evaluation of discovered multiple paths and the tradeoffs between coding opportunity and load balancing, a novel routing metric, Load balanced coding aware routing metric(LCRM) is presented, which considers the load degree of nodes when detects coding opportunities. LCMR could spread traffic over multipath to further balance load. Simulation results demonstrate that LCMR could evenly spread the traffic over the network with increasing network throughput in a heavy load at the expense of some coding opportunities.

关键词： Load balanced Coding aware Multipath Routing wireless mesh networks.

Secure P2P topology based on a multidimensional DHT space mapping

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Science China(Information Sciences) 2013年第5期56卷 224-237页

作者： SUN ZhiXin LUO BingQing CHEN YaDang BU Kai key laboratory of broadband wireless communication and sensor network technology(Nanjing University of Posts and Telecommunications) Ministry of Education State key laboratory for Novel Software technology Nanjing University

Distributed search and routing algorithms based on the DHT(distributed hash table) protocol have attracted considerable attention in structured P2P(peer-to-peer) research as a result of favorable properties such as distribution,self-organization,and high *** with a traditional C/S(client/server) network,the probability of peers initiating malicious behavior increases dramatically because of their self-governing and dynamic characteristics,which also make it harder to satisfy the peers’ security required by *** this paper,we propose a new secure DHT protocol based on a multidimensional mapping *** mechanism maps peers to a multidimensional space by dividing the identifiers into ***,a series of secure methods and routing algorithms are provided to achieve secure DHT in smaller *** with state-ofthe-art approaches,the theoretical analysis and experimental results show that the multidimensional mapping mechanism can effectively improve the average success rate of a resource search by inhibiting malicious behavior.

关键词： multidimensional mapping DHT(distributed hash table) structured P2P(peer-to-peer) network routing attack security