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Cyclostationary Property Based Spectrum Sensing Algorithms for Primary Detection in Cognitive Radio Systems

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Journal of Shanghai Jiaotong university(Science) 2009年第6期14卷 676-680页

作者：岳文静郑宝玉孟庆民 Department of Electronic Engineering Shanghai Jiaotong University institute of signal processing and transmission Nanjing University of Posts and Telecommunications

To implement the primary signal without interference in cognitive radio systems, cognitive radios can detect the presence of the primary user in low SNR. Currently, energy detector is the most common way of spectrum sensing because of its low computational complexity. However, performunce of the method will be possibly degraded due to the uncertainty noise. This paper illustrates the benefits of one-order and two-order cyclostationary properties of primary user＇s signals in time domain. These feature detection techniques in time domain possess the advantages of simple structure and low computational complexity comparing with spectral feature detection methods. Furthermore, performance of the one-order and two-order feature detection is studied and the analytical results are given. Our analysis and numerical results show that the sensing performance of the one-order feature detection is improved significantly comparing with conventional energy detector since it is robust to noise. Meanwhile, numerical results show that the two-order feature detection technique is better than the one-order feature detection. However, this benefit comes at the cost of hardware burdens and power consumption due to the additional multiplying algorithm.

关键词： cognitive radio spectrum sensing cyclostationary feature detection

Performance evaluation of half-duplex relay-based opportunistic cooperation diversity

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Science china(Information Sciences) 2010年第2期53卷 325-334页

作者： ZOU YuLong , ZHENG BaoYu & ZHU Jia institute of signal processing and transmission, nanjing university of posts and telecommunications, nanjing 210003, china 1. institute of signal processing and transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China

Cooperative diversity is proposed as a means to improve the wireless transmission performance, which can effectively combat the wireless fading through sharing the antennas between source and relay nodes. In this paper, considering the practicability, we investigate the use of half-duplex relay, rather than full-duplex relay, for the opportunistic cooperation diversity. Two combining methods, namely selection diversity combining (SDC) and maximum ratio combining (MRC), are utilized for the implementation of the half-duplex relay-based opportunistic cooperation. Closed-form expressions of outage probability are derived for the proposed oppor- tunistic cooperation as well as the known deterministic cooperation over Rayleigh fading channels. Numerical results show that the opportunistic cooperation is superior to the traditional deterministic cooperation in terms of outage probability and, moreover, the MRC-based case outperforms the SDC-based case no matter which duplex mode relay (i.e., half-duplex and full-duplex) is used for the opportunistic cooperation.

关键词： half-duplex relay cooperative diversity SDC MRC outage probability

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 telecommunications, nanjing 210003, china 2College 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

Robust cooperative spectrum sensing schemes for fading channels in cognitive radio networks

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Science china(Information Sciences) 2011年第2期54卷 348-359页

作者： YUE WenJing1,2, ZHENG BaoYu1,2, MENG QingMin1, CUI JingWu1 & XIE PeiZhong1 1institute of signal processing and transmission, nanjing university of posts and telecommunications, nanjing 210003, china 2Department of Electronic Engineering, Shanghai Jiaotong university, Shanghai 200240, 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 China

In cognitive radio systems, cooperative spectrum sensing can detect the presence of the primary user accurately. In practice, however, since the sensing observations are forwarded to a data collector through fading channels, the sensing performance is severely degraded. To deal with this problem, in this paper, we first propose a secondary user selection based cooperative spectrum sensing method to improve sensing performance by decreasing the reporting errors introduced by the fading channels. More specifically, only the secondary users with better signal-to-noise ratio (SNR) for reporting channels are allowed to send their local binary decisions (0 or 1) to the data collector while the others will send nothing. Additionally, we further propose a diversity based cooperative spectrum sensing method which applies existing space-time coding. By exploiting space diversity in CR network, the reporting errors introduced by the fading channel can be decreased and then the sensing performance is improved significantly. For either proposed cooperative spectrum sensing method, the sensing performance is derived and the analytical performance results are given. Our analysis and numerical results verify that proposed methods outperform the conventional cooperative spectrum sensing with OR-rule by taking into account the error effect on the reporting channels.

关键词： cognitive radio (CR) spectrum sensing energy detection diversity technique space-time coding

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 telecommunications,nanjing 210003,china 2 Department of Electronic Engineering,Shanghai Jiaotong university,Shanghai 200240,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

BLIND CHANNEL AND SYMBOL JOINT ESTIMATION IN COOPERATIVE MIMO FOR WIRELESS SENSOR NETWORK

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Journal of Electronics(china) 2008年第4期25卷 439-444页

作者： Yan Zhenya Zheng Baoyu institute of signal processing ＆ transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China

In this paper,application of Sequential Quasi Monte Carlo(SQMC)to blind channel andsymbol joint estimation in cooperative Multiple-Input Multiple-Output(MIMO)system is proposed,which does not need to transmit training symbol and can save the power and channel ***,an improved version of SQMC algorithm by taking advantage of current received signal *** results show that the SQMC method outperforms the Sequential Monte Carlo(SMC)methods,and the incorporation of current received signal improves the performance of theSQMC obviously.

关键词： Cooperative Multiple-Input Multiple-Output (MIMO) Sensor network Sequential Quasi Monte Carlo (SQMC)

Linear beamformer schemes with simple relay selection in MIMO relay networks

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The Journal of china Universities of posts and telecommunications 2008年第4期15卷 24-29+39页

作者： MENG Qing-min 1,2, PAN Su1, ZHENG Bao-yu1, ZHU Hong-bo1, YOU Xiao-hu2 1. Jiangsu Key Laboratory of Wireless Communications and institute of signal processing and transmission, nanjing university of posts and telecommunications, nanjing 210003, china 2. National Mobile Communications Research Lab, Southeast university, nanjing 210096, china [a]Jiangsu Key Laboratory of Wireless Communications and institute of signal processing and transmission nanjing university of posts and telecommunications nanjing 210003 china [b]National Mobile Communications Research Lab Southeast university nanjing 210096 china

This article considers a wireless multi-hop/mesh network where single multi-antenna source-destination pair communicates through a selected relay subset using simple relay selection under the constraint of fixed relay’s number. Compared with random selection, the simple relay selection can yield certain capacity advantages while linear zero-forcing (ZF) receiver and linear beamformer are considered at the relay. For match-filter (MF) beamformer and amplified-and-forward (AF) beamformer with a fixed number of relays, the capacities are given. Furthermore, we extend the simple selection methods to the relaying scheme with orthogonal-triangular (QR) beamformer and investigate these linear beamformer schemes over spatially correlated multi-input multi-output (MIMO) links for both the backward and forward channel over the two-hop MIMO relay networks.

关键词： wireless mesh networks multi-hop relaying capacity beamformer

Multi-Radio Cooperation Technology and Heterogeneous Network Convergence

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ZTE Communications 2008年第3期6卷 29-33页

作者： Huang Chuan, Zheng Baoyu (institute of signal processing and transmission, nanjing university of posts and telecommunications, nanjing 210003, china)

The heterogeneous network convergence is the trend of future network development. However, many bottlenecks exist in the converged system such as high time delay, high energy consumption, and low data rate. Multi-Radio Cooperation (MRC) technology is specially designed to overcome these bottlenecks and to satisfy the requirements of heterogeneous network convergence. MRC can improve network capacity, reduce the energy consumption of radio devices, and decrease handover latency between heterogeneous networks by the cooperation of multiple radios, and by efficient management and feasible allocation of multi-radio resources. MRC makes real seamless heterogeneous network convergence possible.

关键词： Radio rate data Multi-Radio Cooperation Technology and Heterogeneous Network Convergence MRC WMN

Recognition of Continuous Digits by Quantum Neural Networks

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The Journal of china Universities of posts and telecommunications 2003年第1期10卷 29-33页

作者： LI Fei, ZHAO Sheng-mei, ZHENG Bao-yu (institute of signal & Information processing, nanjing university of posts and telecommunications, nanjing 210003, P.R. china) institute of signal & Information processing Nanjing University of Posts and Telecommunications Nanjing 210003

This paper describes a new kind of neural network-Quantum Neural Network(QNN) and its application to recognition of continuous digits. QNN combines the advantages of neuralmodeling and fuzzy theoretic principles . Experiment results show that more than 15 percent errorreduction is achieved on a speaker-independent continuous digits recognition task compared with BPnetworks.

关键词： quantum neural net-work quantum neuron speech recognition