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Proactive Spectrum Monitoring for Suspicious Wireless Powered Communications in Dynamic Spectrum Sharing Networks

China Communications 2021年第12期18卷 119-138页

作者： Yu Zhang Guojie Hu yueming cai College of Communications Engineering Army of Engineering UniversityNanjing 210007China Sixtythird Research Institute National University of Defense TechnologyNanjing 210007China Rocket Force University of Engineering Xi’an 710025China

This paper studies the proactive spec-trum monitoring with one half-duplex spectrum moni-tor(SM)to cope with the potential suspicious wireless powered communications(SWPC)in dynamic spec-trum sharing *** jamming-assisted spec-trum monitoring scheme via spectrum monitoring data(SMD)transmission is proposed to maximize the sum ergodic monitoring rate at *** SWPC,the suspi-cious communications of each data block occupy mul-tiple independent blocks,with a block dedicated to the wireless energy transfer by the energy-constrained suspicious nodes with locations in a same cluster(symmetric scene)or randomly distributed(asymmet-ric scene)and the remaining blocks used for the in-formation transmission from suspicious transmitters(STs)to suspicious destination(SD).For the sym-metric scene,with a given number of blocks for SMD transmission,namely the jamming operation,we first reveal that SM should transmit SMD signal(jam the SD)with tolerable maximum power in the given *** perceived suspicious signal power at SM could be maximized,and thus so does the correspond-ing sum ergodic monitoring ***,we further reveal one fundamental trade-off in deciding the op-timal number of given blocks for SMD *** the asymmetric scene,a low-complexity greedy block selection scheme is proposed to guarantee the optimal *** results show that the jamming-assisted spectrum monitoring schemes via SMD transmission achieve much better perfor-mance than conventional passive spectrum monitor-ing,since the proposed schemes can obtain more accu-rate and effective spectrum characteristic parameters,which provide basic support for fine-grained spectrum management and a solution for spectrum security in dynamic spectrum sharing network.

关键词： proactive spectrum monitoring sum er-godic monitoring rate jamming-assisted proactive spectrum monitoring half-duplex fundamental trade-off dynamic spectrum sharing network

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Maximum-likelihood detection based on branch and bound algorithm for MIMO systems

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Science in China(Series F) 2008年第3期51卷 306-319页

作者： LI Zi cai yueming Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

Maximum likelihood detection for MIMO systems can be formulated as an integer quadratic programming problem. In this paper, we introduce depth-first branch and bound algorithm with variable dichotomy into MIMO detection. More nodes may be pruned with this structure. At each stage of the branch and bound algorithm, active set algorithm is adopted to solve the dual subproblem. In order to reduce the complexity further, the Cholesky factorization update is presented to solve the linear system at each iteration of active set algorithm efficiently. By relaxing the pruning conditions, we also present the quasi branch and bound algorithm which implements a good tradeoff between performance and complexity. Numerical results show that the complexity of MIMO detection based on branch and bound algorithm is very low, especially in low SNR and large constellations.

关键词： multiple-input multiple-output (MIMO) detection branch and bound active set dual Cholesky factorization

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Secure Transmission for NOMA Systems with Imperfect SIC

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China Communications 2020年第11期17卷 67-78页

作者： Zhongwu Xiang Xiaobing Tong yueming cai College of Communications Engineering Army Engineering University of PLANanjing 210007China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of EngineeringWuhan 430033China

This paper investigates secure transmission for non-orthogonal multiple access(NOMA)systems where the imperfect successive interference cancellation(SIC)is considered at both legitimate users and eavesdropper(Eve).A power allocation scheme is designed for the legitimate users to mitigate the effect of the SIC error caused by imperfect *** characterizing the secrecy performance of the NOMA system,the closed-form expressions for connection outage probability(COP),secrecy outage probability(SOP),and effective secrecy throughput(EST)are derived over Nakagami-m fading channels in both NOMA and benchmark orthogonal multiple access(OMA)*** also provide security and reliability trade-off results(SRT)for the users in the NOMA and OMA *** results verify our analysis and show that the strong users achieve better secrecy performance but worse reliability performance and NOMA outperforms OMA in terms of SRT.

关键词： physical layer security non-orthogonal multiple access imperfect SIC security and reliability trade-off

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Outage performance of OFDM-based selective decode-and-forward cooperative networks over Weibull fading channels

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High Technology Letters 2011年第3期17卷 285-289页

作者： cai Chunxiao Yang Wendong cai yueming Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 P. R. China National Mobile Communications Research Laboratory Southeast University Nanjing 210096P. R. China

The outage performance of OFDM-based decode-and-forward cooperative networks is studied. The channels are modeled as independent Weibull distributed coefficients. A closed-form expression for the outage probability is obtained for three selective relaying schemes in the Weibull fading channels and a derived optimum power allocation method based on the closed form expressions of outage probability debases the outage probability. Monte Carlo simulations verify the analytical results.

关键词： OFDM cooperative communication Weibull fading channels decode-and-forward outage probability.

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Secure Short-Packet Transmission in Uplink Massive MU-MIMO Assisted URLLC Under Imperfect CSI

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China Communications 2023年第12期20卷 196-211页

作者： Tian Yu Xiaoli Sun yueming cai Zeyuan Zhu Army Engineering University of PLA Nanjing 210007China Unit 31401 of PLA Jinan 250002China PLA Strategic Support Force Information Engineering University Zhengzhou 450001China

Ultra-reliable and low-latency communication(URLLC)is still in the early stage of research due to its two strict and conflicting requirements,i.e.,ultra-low latency and ultra-high reliability,and its impact on security performance is still ***,short-packet communication is expected to meet the delay requirement of URLLC,while the degradation of reliability caused by it makes traditional physical-layer security metrics not *** this paper,we investigate the secure short-packet transmission in uplink massive multiuser multiple-inputmultiple-output(MU-MIMO)system under imperfect channel state information(CSI).We propose an artificial noise scheme to improve the security performance of the system and use the system average secrecy throughput(AST)as the analysis *** derive the approximate closed-form expression of the system AST and further analyze the system asymptotic performance in two ***,a one-dimensional search method is used to optimize the maximum system AST for a given pilot *** results verify the correctness of theoretical analysis,and show that there are some parameters that affect the tradeoff between security and ***,appropriately increasing the number of antennas at the base station(BS)and transmission power at user devices(UDs)can increase the system AST to achieve the required threshold.

关键词： average secrecy throughput imperfect CSI massive MU-MIMO physical-layer security short-packet

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Power allocation for non-orthogonal decode-andforward cooperation protocol

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Science in China(Series F) 2009年第6期52卷 1037-1042页

作者： ZHANG Yong XU YouYun cai yueming Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 China

This paper studies the power allocation problem for the non-orthogonal decode-and-forward （NDF） cooperation protocol with selection *** the availability of the magnitudes of all channel gains at the source, the power allocation is explored that maximizes the mutual information between the source and destination subject to a total power *** minimum power that avoids the outage of the relay is set as a condition, under which the power allocation problem becomes one of selecting the optimal one from several allocation factor *** is shown that the power allocation scheme can provide considerable performance gain, and the non-orthogonal cooperation protocol is superior to the orthogonal protocol and direct transmission.

关键词： non-orthogonal decode-and-forward power allocation relaying

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Cooperative multiple access channels: Achievable rates and optimal resource allocation

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Science in China(Series F) 2009年第8期52卷 1428-1438页

作者： PAN ChengKang cai yueming XU YouYun Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 China

We investigate the multiple access channels （MAC） where sources can cooperate via half-duplex relaying and refer to it as cooperative MAC channels （CMAC）. Assuming perfect channel state information （CSI） at the transmitters and the receivers, we determine the bounds on the achievable rate region of a Gaussian CMAC channel and an inner bound on the outage capacity region of a fading CMAC channel. Based on superposition modulation, a half-duplex cooperative relay scheme with optimal resource allocation is proposed to achieve the bounds of capacity region. Analytical results and simulation results show that the achievable rate region of a Gaussian CMAC channel is larger than that of a Gaussian MAC channel with direct transmission （DT） schemes. But they have the same achievable sum rate. Moreover, the proposed scheme can provide higher outage capacity region than DT schemes in a fading MAC channel due to the fact that sources can share the resources with each other to reduce outages.

关键词： multiple access channel cooperative communication rate region resource allocation

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Channel-aware multi-user uplink transmission scheme for SIMO-OFDM systems

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Science in China(Series F) 2009年第9期52卷 1678-1687页

作者： PAN ChengKang cai yueming XU YouYun Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 China

The problem of medium access control （MAC） in wireless single-input multiple-output-orthogonal frequency division multiplexing （SIMO-OFDM） systems is addressed. Traditional random access protocols have low overheads and inferior performance. Centralized methods have superior performance and high overheads. To achieve the tradeoff between overhead and performance, we propose a channelaware uplink transmission （CaUT） scheme for SIMO-OFDM systems. In CaUT, users transmit requestto-send （RTS） at some subcarriers whose channel gains are above a predetermined threshold. Using the channel state information provided by RTS, access point performs user selection with receive beamforming to decide which users can access and then broadcasts the selection results via clear-to-send （CTS） to users. We present a distributed power control scheme by using a simple fixed modulation mode. We optimize the modulation order and channel gain thresholds to maximize the separable packets subject to the bit-error-rate （BER） and temporal fairness requirements and the individual average transmit power constraints. The performance of CaUT scheme is analyzed analytically and evaluated by simulations. Simulation results show that CaUT can achieve more significant throughput performance than traditional random access protocols.

关键词： SIMO-OFDM medium access control signal processing receive beamforming

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Distributed space-time-frequency coding for cooperative OFDM systems

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Science in China(Series F) 2009年第12期52卷 2424-2432页

作者： YANG WeiWei cai yueming WANG Lei Institute of Communications Engineering PLA University of Science and Technology Nanjing 210007 China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

A distributed space-time-frequency （STF） coding scheme is proposed for cooperative OFDM （C-OFDM） systems with three terminals over quasi-static frequency-selective Rayleigh fading channels, The outage probability is derived and its tight closed-form lower bound is presented. Asymptotic analysis indicates that the proposed scheme can achieve both spatial and multipath （frequency） diversity. The theoretical analysis of the proposed STF coded scheme is further implemented by the distributed group STF block coding （D-GSTFBC） scheme based on the subcarrier grouping technique, Simulation results confirm the previously introduced theoretical analysis.

关键词： cooperative diversity multipath channel space-time-frequency (STF) coding

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Dynamic Update Scheme of Spectrum Information Based on Spectrum Opportunity Incentive in the Database-Assisted Dynamic Spectrum Management

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China Communications 2024年第3期21卷 75-90页

作者： Zhang Yu Chen Yong He Panfeng cai yueming Sixty-third Research Institute National University of Defense TechnologyNanjing 210007China College of Communications Engineering Army of Engineering UniversityNanjing 210007China

To solve the problem of delayed update of spectrum information(SI) in the database assisted dynamic spectrum management(DB-DSM), this paper studies a novel dynamic update scheme of SI in DB-DSM. Firstly, a dynamic update mechanism of SI based on spectrum opportunity incentive is established, in which spectrum users are encouraged to actively assist the database to update SI in real time. Secondly, the information update contribution(IUC) of spectrum opportunity is defined to describe the cost of accessing spectrum opportunity for heterogeneous spectrum users, and the profit of SI update obtained by the database from spectrum allocation. The process that the database determines the IUC of spectrum opportunity and spectrum user selects spectrum opportunity is mapped to a Hotelling model. Thirdly, the process of determining the IUC of spectrum opportunities is further modelled as a Stackelberg game by establishing multiple virtual spectrum resource providers(VSRPs) in the database. It is proved that there is a Nash Equilibrium in the game of determining the IUC of spectrum opportunities by VSRPs. Finally, an algorithm of determining the IUC based on a genetic algorithm is designed to achieve the optimal IUC. The-oretical analysis and simulation results show that the proposed method can quickly find the optimal solution of the IUC, and ensure that the spectrum resource provider can obtain the optimal profit of SI update.

关键词： database-assisted dynamic spectrum management Hotelling information updating contribution spectrum information updating Stackelberg

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