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Graph theory based physical cell identity self-configuration for LTE-A network

The Journal of China Universities of Posts and Telecommunications 2013年第1期20卷 101-107页

作者： WEI Yao WANG Wen-bo PENG Mu-gen MIN Shi-jun Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Wireless Signal Processing and Network Laboratory Beijing University of Posts and Telecommunications

Self-configuration of physical cell identity （PCI） is a key feature for the long term evolution advanced （LTE-A） network. The PCI is used to identify the different cells in the system, becoming an essential cell configuration parameter. Considering the uncoordinated deployments of the evolved Node B （eNodeB） and the limited number of PCI, the PCI assignment for cells would be quite complex. This paper presents and puts forward a graph theory based centralized PCI self-configuration scheme （GT-PCIS）. The PCI self-configuration problem is mapped to the well-known minimum spanning tree （MST） problem in order to optimize the PCI reuse distance and decrease the multiplexing interference throughout the entire network. The proposal provides a greedy search to make the locally optimal selection of PCI at each stage, and to achieve a global optimum. To demonstrate the algorithm validity, performances of GT-PCIS and manual configuration are evaluated. Simulation results show that the proposed GT-PCIS outperforms other configuration algorithms even under the condition of severe PCI deficiency.

关键词： LTE-A PCI MST self-configuration

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A FULL-COOPERATIVE DIVERSITY BEAMFORMING SCHEME IN TWO-WAY AMPLIFIED-AND-FORWARD RELAY SYSTEMS

A FULL-COOPERATIVE DIVERSITY BEAMFORMING SCHEME IN TWO-WAY A...

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European signal processing Conference

作者： Zhongyuan Zhao Zhiguo Ding Mugen Peng H. Vincent Poor Wireless Signal Processing and Network Laboratory Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications School of Electrical Electronic and Computer Engineering Newcastle University School of Engineering and Applied Science Princeton University

ISBN: (纸本)9781479946037

Consider a simple two-way relaying channel in which two single-antenna sources exchange information via a multiple-antenna relay. For such a scenario, all the existing approaches that can achieve full cooperative diversity order are based on antenna/relay selection, for which the difficulty in designing the beamforming lies in the fact that a single beamformer needs to serve two destinations. In this paper, a new full-cooperative diversity beamforming scheme that ensures that the relay signals are coherently combined at both destinations is proposed. Both analytical and numerical results are provided to demonstrate the performance gains.

关键词： Two-way relay systems Beamforming Network coding Amplify-and-forward Cooperative diversity

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Delay aware cell association and user scheduling in heterogeneous overlay networks

Delay aware cell association and user scheduling in heteroge...

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2013 IEEE 24th International Symposium on Personal, Indoor and Mobile Radio communications, PIMRC Workshops 2013

作者： Li, Jian Li, Yuan Cheng, Aolin Peng, Mugen Wireless Signal Processing and Network Laboratory Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

ISBN: (纸本)9781479901227

In this paper, we propose a two timescale delay aware cell association and user scheduling design for downlink heterogeneous overlay networks. The cell association is adaptive to the global queue state information(QSI) over a longer timescale while the user scheduling is adaptive to both intra-cell queue state information(QSI) and intra-cell channel state information(CSI) and computed locally at each base stations(BSs) over a shorter timescale. The delay aware control is formulated as an infinite horizon partially observed Markov decision process(POMDP) and an equivalent Bellman equation in terms of cell association pattern Q-factor is derived. To reduce the computational complexity and facilitate distributed implementation, the cell association pattern Q-factor is approximated by the sum of per cell potential function, which can be further decomposed under specific assumption. After that, a novel distributed learning algorithm for potential function is proposed. The simulation results show that the proposed design outperforms the traditional cell association and user scheduling schemes and the learning algorithm converges surely. © 2013 IEEE.

关键词： Channel state information

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An new optimal decision threshold criterion for broadband-based energy detection with performance constraints

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2013 International Conference on Advances in Materials Science and Manufacturing Technology, AMSMT 2013

作者： Liu, Wen Wen Yuan, Long Liu, Zi Yang Peng, Tao Wang, Wen Bo Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9783037857984

We study on the energy detection algorithm of spectrum sensing. The performance of energy detection in spectrum sensing is measured by the false alarm probability and the missing detection probability. In a certain spectrum sharing environment, whether the energy detection algorithm can meet our requirement is depending on the length of observation time and the decision threshold selected. Several experiment results have shown that: when the decision threshold is too low, it will cause much more false alarm;when the decision threshold is too high, it will bring many missing detection. Therefore, it is crucial that choosing an optimal decision threshold according to the length of observation time. In this paper, the closed-form solution of the minimum-cost decision threshold is deduced by using the methodology of mathematical derivation, and a new criterion about selecting an optimal decision threshold is also proposed. At last, the conclusion is proved by simulation. © (2013) Trans Tech Publications, Switzerland.

关键词： Alarm systems

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Quantum key distribution with the single-photon-added coherent source

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Physical Review A 2014年第6期90卷 062315-062315页

作者： Dong Wang Mo Li Feng Zhu Zhen-Qiang Yin Wei Chen Zheng-Fu Han Guang-Can Guo Qin Wang Key Laboratory of Quantum Information University of Science and Technology of China CAS Hefei Anhui 230026 China Synergetic Innovation Center of Quantum Information & Quantum Physics University of Science and Technology of China Hefei Anhui 230026 China Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China

In this paper, we present schemes on implementing the single-photon-added coherent source in quantum key distributions. We apply this source in either the standard BB84 protocol or the recently proposed measurement-device-independent quantum key distribution, comparing their performance with the cases of using other existing sources, e.g., the weak coherent source or the heralded single-photon source, and giving out corresponding numerical simulations. Our simulation results show that in both protocols the single-photon-added coherent source can greatly exceed all other existing sources. Moreover, even when taking statistical fluctuation into account, a high key generation rate can still be achieved at long distance by applying this source.

关键词： SINGLE photon generation QUANTUM measurement COHERENT scattering QUANTUM communication (Optics) QUANTUM states

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Improved SRS Design and Channel Estimation for LTE-Advanced Uplink

Improved SRS Design and Channel Estimation for LTE-Advanced ...

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2013 IEEE 5th International Symposium on Microwave,Antenna,Propagation and EMC Technologies for wireless communications

作者： Xingyu Xia Hui Zhao Chengcheng Zhang Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts & Telecommunications

ISBN: (纸本)9781467360760

In 3GPP long term evolution(LTE) specification for uplink,single antenna for transmission is adopted due to its ***,when it evolves to LTE-A,more transmit antennas are needed for higher spectrum efficiency,which means more reference *** the physical uplink share channel(PUSCH) of LTE-A,the estimated channel based on sounding reference signal(SRS) is used for precoder and modulation and coding scheme(MCS) *** this paper,an improved SRS design is proposed,which achieves minimum interference between different reference *** importantly,it is perfectly backwards compatible with the SRS in LTE *** addition,we propose an improved SRS channel estimation for multiple transmit *** results show that the proposed SRS design leads to less channel estimation error,and the proposed SRS channel estimation can reach similar accuracy to exponential power delay profile(PDP) channel estimation,while with much lower complexity.

关键词： LTE-A uplink SRS channel estimation MIMO channel estimation up link spectral efficiency minimum interference Reference signals Long Term Evolution

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Optimal Relay Location and Power Allocation for Rayleigh-fading Channels in Cognitive Relay Networks

Optimal Relay Location and Power Allocation for Rayleigh-fad...

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IEEE International Symposium on Personal, Indoor and Mobile Radio communications

作者： Lefei Wang Tao Peng Bo Peng Wenbo Wang Wireless Signal Processing and Network Lab Key laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts & Telecommunications

ISBN: (纸本)9781467362337

Cognitive relay networks have been studied for the advantages of improving the throughput of secondary users. Relay location and power allocation are the key issues in cognitive relay networks, which impact on the system performance. In this paper, we analyze the problem of optimal relay location and power allocation in cognitive relay networks. Firstly, we deduce an ergodic capacity formula for the secondary users reuse the resource of one primary user in Rayleigh-fading channels, and the formula is used in the terms of high signal-to-noise ratio (SNR) and high interference-to-noise ratio (INR). Then, the expressions for optimal relay location and power allocation are derived from the deduced formula when the distances among primary users and secondary users are known. At last, an ergodic algorithm for finding the results is given. The simulation proves the proposed ergodic capacity formula is correct. The ergodic algorithm is also verified by simulation, and the optimal relay location and power can be also determined.

关键词： Relay location Power allocation Ergodic capacity Rayleigh-fading channels Cognitive relay networks

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Performance Analysis of Device-to-Device Underlay communication in Rician Fading Channels

Performance Analysis of Device-to-Device Underlay Communicat...

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IEEE Global communications Conference

作者： Yuan Li Jian Li Jiamo Jiang Mugen Peng Wireless Signal Processing and Network Laboratory Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications

ISBN: (纸本)9781479913510

Device-to-device (D2D) communication has been developed as a promising technology to meet the unrelenting demand for high data rate services by providing a direct link between users. In this paper, we investigate the performance of D2D communications underlaying cellular networks using stochastic geometry, where Rician fading is modeled to characterize the line-of-sight (LoS) component in the D2D direct link. In order to avoid causing harmful interference to the cellular network, we divide the whole bandwidth into two parts, namely shared subchannels, which are jointly used by the cellular network and D2D connections, and dedicated subchannels, which are exclusively used by the cellular network. The cellular and D2D performances are evaluated in terms of both success probability and average achievable throughput. Furthermore, we provide insights into the optimal subchannel allocation ratio under the quality-of-service (QoS) guarantee of the cellular network. Numerical results demonstrate the impact of Rician K-factor on the D2D performance as well as the benefit provided by the subchannel allocation scheme.

关键词： Device-to-device Stochastic geometry Success probability Average achievable throughput Interference management

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Importance sampling estimation on call dropping probability for a handover scheme under poisson assumption

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Information Technology Journal 2013年第16期12卷 3639-3644页

作者： Liang, D. Xue, W.Q. Peng, M.G. Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications Beijing 100876 China

The process of changing the channel associated with the current connection while a call is in progress is under consideration. The estimation of call dropping probability in handover process of a one dimensional traffic system in 3GPP LTE is discussed. The analytical probability of call dropping is deduced and then estimated by Monte Carlo simulation. As the call dropping probability is always very small, it can be considered as rare event. To reduce the sample size of simulation, importance sampling is used by increasing the probability of average coming rate for handover traffic and decreasing the probability of available channels. The simulation results suggest the sample size can be tremendously reduced by using importance sampling. © 2013 Asian Network for Scientific Information.

关键词： Poisson distribution

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Trade-off of average area spectrum efficiency and energy efficiency

Trade-off of average area spectrum efficiency and energy eff...

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IEEE Conference on wireless communications and networking

作者： Long Zhao Hui Zhao Kan Zheng Xingyu Xia Chengcheng Zhang Key Laboratory of Universal Wireless Communication Ministry of Education Wireless Signal Processing & Network Lab Beijing University of Posts and Telecommunications Beijing China

ISBN: (纸本)9781467359382

Green communications is put forward to decrease the operational expenditure (OpEx) and carbon emission of communication networks in recent years. The relationship between spectrum efficiency (SE) and energy efficiency (EE) has induced more attentions in academic field, however, most efforts are spent on SE-EE trade-off of link-level not system-level. In this paper, we analyze the trade-off between average area SE (A 2 SE) and EE under the realistic power consumption model (PCM) in system-level perspective. First, we give the theoretical closed-form expression of A 2 SE for a cell as a function of edge SNR. And then, closed-form approximation (CFA) of A 2 SE is derived, and it largely coincides with theoretical A 2 SE and is reversible. Based on the CFA, we find the closed-form trade-off of A 2 SEEE concisely. Further, the optimal EE, corresponding A 2 SE and transmission power of BS under different cell radiuses are got according to the A 2 SE-EE trade-off. These results are helpful to design cell radius and transmission power which meet different needs for A 2 SE and EE of wireless networks.

关键词： Phase change materials signal to noise ratio Computer architecture wireless networks Microprocessors Power demand

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