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On power allocation for a cognitive radio network with hybrid spectrum sharing

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science china(Information sciences) 2011年第11期54卷 2425-2434页

作者： ZHANG Jing 1,2.3 & ZHU HongBo 1 1 Key Laboratory of Wireless Communications of Jiangsu Province,nanjing University of posts & {2.,nanjing 2.0003,china 2.college of electronic science & engineering,nanjing University of posts & {2.,nanjing 2.0003,china 3 State Key Laboratory of Millimeter Waves,nanjing 2.0096,china 1. Key Laboratory of Wireless Communications of Jiangsu Province Nanjing University of Posts & Telecommunications Nanjing 210003 China2. College of Electronic Science & Engineering Nanjing University of Posts & Telecommunications Nanjing 210003 China3. State Key Laboratory of Millimeter Waves Nanjing 210096 China

In this study we propose a hybrid spectrum sharing scheme based on power control by combining Overlay with Underlay schemes,to improve radio spectrum *** the scheme,the secondary users dynamically switch their operational states between Overlay and Underlay according to the spectrum *** the dynamics of the primary network is first modeled with a discrete-state Markov process to find the time fraction of secondary users in the Overlay state and that in the Underlay state,which leads to the capacity model of the hybrid spectrum sharing *** the criterion of maximizing capacity,the power allocation of the cognitive network is researched and the optimum power allocation for secondary users is *** a result,the maximum achievable capacity of the cognitive network is *** are given to prove the analysis *** and simulated results indicate that hybrid spectrum sharing based on power control provides a higher capacity than single Overlay and Underlay systems for the cognitive network,i.e.,hybrid spectrum sharing can further improve radio spectrum efficiency.

关键词： cognitive radio network hybrid spectrum sharing primary network dynamics power allocation achievable capacity

A new measure to characterize multifractality of sleep electroencephalogram

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science Bulletin 2006年第24期51卷 3059-3064页

作者： MA Qianli1,2.NING Xinbao1,WANG Jun2.& BIAN Chunhua1 1. State Key Laboratory of Modern Acoustics,Department of electronics science and {2.,Institute for Biomedical electronic Engi-neering,nanjing University,nanjing 2.0093,china 2. Province Key Laboratory of Image Processing & Image Communica-tion,college of telecommunications and Information {2.,nanjing University of posts & telecommunications,nanjing 2.0003,china State Key Laboratory of Modern Acoustics Department of Electronics Science and Engineering Institute for Biomedical Electronic Engineering Nanjing University Nanjing 210093 China Province Key Laboratory of Image Processing & Image Communication College of Telecommunications and Information Engineering Nanjing University of Posts & Telecommunications Nanjing 210003 China

Traditional methods for nonlinear dy-namic analysis,such as correlation dimension,Lyapunov exponent,approximate entropy,detrended fluctuation analysis,using a single parameter,cannot fully describe the extremely sophisticated behavior of electroencephalogram (EEG). The multifractal for-malism reveals more “hidden” information of EEG by using singularity spectrum to characterize its nonlin-ear dynamics. In this paper,the zero-crossing time intervals of sleep EEG were studied using multifractal analysis. A new multifractal measure Δasα was pro-posed to describe the asymmetry of singularity spec-trum,and compared with the singularity strength range Δα that was normally used as a degree indi-cator of multifractality. One-way analysis of variance and multiple comparison tests showed that the new measure we proposed gave better discrimination of sleep stages,especially in the discrimination be-tween sleep and awake,and between sleep stages 3 and 4.

关键词： sleep electroencephalogram multifractality.

Achievable bit rates of cognitive user with Vandermonde precoder in cognitive radio network

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science china(Information sciences) 2011年第7期54卷 1471-1480页

作者： XU XiaoRong 1,ZHANG JianWu 1 & ZHENG BaoYu 2.1 college of Telecommunication engineering,Hangzhou Dianzi University,Hangzhou 310018,{2. 2.Institute of Signal Processing and Transmission,nanjing University of posts and telecommunications,nanjing 2.0003,{2. 1. college of Telecommunication engineering Hangzhou Dianzi University Hangzhou 310018 China2. Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China

In cognitive radio network (CRN) where primary user (PU) and secondary user (SU) wish to communicate with their corresponding receivers simultaneously over frequency selective fading channels,the interference between PU and SU should be eliminated in order to realize spectrum *** division multiple access (PDMA) that implements Vandermonde precoder in cognitive orthogonal frequency division multiplexing (OFDM) is proposed,which benefits from the frequency selectivity of the cognitive channel to form a frequency *** precoder enables SUs to achieve higher bit rate with optimal power allocation strategy under the condition of PU interference *** and simulation results are presented to prove theoretical *** is shown that,achievable bit rates (ABR) of SU could be achieved with optimal power allocation scheme in ***,it is also verified that,with Vandermonde precoder to form PDMA,SU’s signal-to-noise ratio (SNR) and the target rate of PU could impact the ABR of SU significantly in CRN.

关键词： achievable bit rates (ABR) Vandermonde precoder precoder division multiple access (PDMA) optimal power allocation cognitive radio network (CRN)

Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

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science china(Information sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2.& FENG GuangZeng3 1Department of electronic and Information engineering, Zhejiang Institute of Media and Communications, Hangzhou 310018, {2. 2.epartment of Information engineering, Jiangsu City Vocation college, nanjing 2.0036, {2. 3college of Communication and Information engineering, nanjing University of posts and telecommunications, {12., {2. 1. Department of electronic and Information engineering Zhejiang Institute of Media and Communications Hangzhou 310018 China2. Department of Information Engineering Jiangsu City Vocation College Nanjing 210036 China3. College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding

Research on heart sound identification technology

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science china(Information sciences) 2012年第2期55卷 281-292页

作者： CHENG XieFeng1,3,MA Yong2.LIU Chen1,ZHANG XueJun1 & GUO YuFeng11School of electronic science and {2.,nanjing University of posts and telecommunications,nanjing 2.0003,china 2.chool of Computer science and Technology,nanjing University of science and Technology,nanjing 2.0094,china 3Key Lab of Broudbard Wireless Communication and Sensor Network Technology(nanjing University of posts and telecommunications),Ministry of Education,nanjing 2.0094,china 1. School of electronic science and {2. Nanjing University of Posts and Telecommunications Nanjing 210003 China3. Ministry of Education Key Lab of Broudbard Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications) Nanjing 210094 China2. School of Computer Science and Technology Nanjing University of Science and Technology Nanjing 210094 China

In this article,both the basic principles and the experimental methods of identity recognition technology based on heart sounds are ***,the characteristics of heart sounds and the feasibility of heart sounds as a biometric were analyzed.A synthetic model of heart sounds was then developed based on a family of wavelets;Finally,the characteristic parameters of heart sounds were extracted by using the heart sounds linear band frequency cepstra(HS-LBFC)with a specified configuration,and the similarity distance was adopted for heart sound *** highlight the difference in two heart sound signals between the time and frequency domains,a construction method of the heart sound wavelet,a calculation method of the parameters of a synthetic model,selection of the characteristic parameters of heart sounds and the corresponding data processing technology were *** experimental results showed that the proposed method exhibited excellent performance and practicability.

关键词： biometric wavelet family of heart sounds synthetic model of heart sounds heart sounds linear band frequency cepstra(HS-LBFC)

A novel multi-relay cross-layer cooperative communication strategy based on Jackson queuing model

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science china(Information sciences) 2010年第4期53卷 842-853页

作者： XU XiaoRong1,2. & ZHENG BaoYu1 1Institute of Signal Processing and Transmission, nanjing University of posts and {2., nanjing 2.0003, china 2.5} of Telecommunication engineering, Hangzhou Dianzi University, Hangzhou 310018, china Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China college of Telecommunication engineering Hangzhou Dianzi University Hangzhou China

A novel multi-relay cooperative communication strategy based on Jackson queuing model is pro-posed, which is implemented via a cross-layer design between the physical (PHY) layer and the medium access control (MAC) layer. In the PHY layer, we focus mainly on system outage performance by analyzing in detail the relationship between the SNR threshold and the outage probabilities. While in the MAC layer, system model is treated as a Jackson queuing network, and the queue discipline for each node is assumed to be GI/M/1 model. System throughput and delay performance for the proposed strategy are also illustrated. Simulation results of the proposed cross-layer scheme are presented to validate our theoretical derivations. It is revealed that, the number of cooperative nodes influences system outage performance at high spectral efficiency regimes in the PHY layer while the proposed strategy provides a better throughput and delay performance than conventional schemes in the MAC layer.

关键词： multi-relay cooperative communication cross-layer design Jackson queuing model outage prob- abilities GI/M/1 model system throughput delay performance

An Exact Virtual Network Embedding Algorithm Based on Integer Linear Programming for Virtual Network Request with Location Constraint

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china Communications 2016年第8期13卷 177-183页

作者： Zeheng Yang Yongan Guo School of Computer science and engineering University of Electronic Science and Technology of China(UESTC) college of telecommunications and Information {2. Nanjing University of Posts and Telecommunications

Network virtualization is known as a promising technology to tackle the ossification of current Internet and will play an important role in the future network area. Virtual network embedding(VNE) is a key issue in network virtualization. VNE is NP-hard and former VNE algorithms are mostly heuristic in the *** exact algorithms have been developed in recent years. However, the constraints of exact VNE are only node capacity and link *** on these, this paper presents an exact VNE algorithm, ILP-LC, which is based on Integer Linear Programming(ILP), for embedding virtual network request with location constraints. This novel algorithm is aiming at mapping virtual network request(VNR) successfully as many as possible and consuming less substrate *** topology of each VNR is randomly generated by Waxman model. Simulation results show that the proposed ILP-LC algorithm outperforms the typical heuristic algorithms in terms of the VNR acceptance ratio, at least 15%.

关键词： network virtualization virtual network embedding exact VNE algorithm integer linear Programming location constraint VNR acceptance ratio

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Optimal power allocation for cognitive relay networks: amplify-and-forward versus selection relay

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science china(Information sciences) 2011年第4期54卷 861-872页

作者： YUE WenJing 1,2.ZHENG BaoYu 1,2.MENG QingMin 1,YUE WenJie 3 & CUI JingWu 1 1 Institute of Signal Processing and Transmission,nanjing University of posts and {2.,nanjing 2.0003,china 2.Department of electronic engineering,Shanghai Jiaotong University,Shanghai 2.02.0,china 3 Shanxi Institute of Educational science,Taiyuan 030009,china 1. Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China2. Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China3. Shanxi Institute of Educational Science Taiyuan 030009 China

We consider a cognitive relay network which is defined by a source,a destination,and cognitive relay nodes and primary user *** this network,a source is assisted by cognitive relay nodes which allow coexisting with primary user nodes by imposing severe constraints on the transmission power so that they operate below the noise floor of primary user *** this paper,we mainly study the power allocation strategies of this system to minimize the outage probability subject to total and individual power constraints for cognitive relay nodes and subject to interference constraints for primary user nodes.A relay transmission scheme,namely amplify-and-forward (AF),is *** first present an optimal power allocation (OPA) scheme to minimize the system outage probability,based on instantaneous channel state information among the source,destination and relay nodes and mean channel gains between primary user nodes and cognitive ***,we propose a selection AF scheme (S-AF) where the single best relay is chosen to assist in the transmission and study power allocation strategy for S-AF to minimize outage *** analytical power allocation strategies have been validated through numerical *** results indicate that the AF with OPA and S-AF with OPA have significantly better outage behavior and average throughput than AF and S-AF schemes *** also find that S-AF with OPA achieves a higher throughput,and hence lower outage probability than AF with OPA.

关键词： cognitive radio (CR) relay networks power allocation outage probability

Asymptotic SEP of MIMO beamforming in two-hop AF relaying systems

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science china(Information sciences) 2012年第2期55卷 377-383页

作者： FU YouHua1,HAN YuJie2.YANG LvXi2.ZHU WeiPing3 & LIU Chen1 1School of electronic science and {2.,nanjing University of posts and telecommunications,nanjing 2.0003,china 2.chool of Information science and {2.,Southeast University,nanjing 2.0096,china 3Department of Electrical and Computer {2.,Concordia University,Montreal H3G 1M8,Canada 1. School of electronic science and {2. Nanjing University of Posts and Telecommunications Nanjing 210003 China2. School of Information Science and Engineering Southeast University Nanjing 210096 China3. Department of Electrical and Computer Engineering Concordia University Montreal H3G 1M8 Canada

This paper derives an asymptotic average symbol error probability(SEP)expression for multiple-input multiple-output(MIMO)two-hop amplify-and-forward(AF)relay systems with optimal *** analysis at high signal-to-noise ratio(SNR)quantifies the diversity order and array gain,which are valid for any antenna numbers of the terminals and arbitrary channel fading *** is also proved that the system performance is dominated by the relatively degraded one of the two-hop *** results based on the simple expressions provide valuable insights into the performance and practical design considerations of MIMO AF networks.

关键词： MIMO relay networks optimal beamforming symbol error probability(SEP) diversity order