Huaxia Chen

Shanghai Institute of Microsystem And Information Technology, Shanghai, Shanghai Shi, China

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Publications (6)4.71 Total impact

  • Tianheng Xu, Huaxia Chen, Honglin Hu
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    ABSTRACT: Based on the bijective mapping between cyclostationary features and the cyclic delays in orthogonal frequency division multiplexing (OFDM) systems, cyclostationary signatures can be used for signal representation in statistical spectrum domain. However, the conventional detection method for this kind of statistical signals is hindered by huge computational complexity. In this letter, we propose a novel detection method for such statistical signals with cyclostationarity, which only extract local features on the cyclic autocorrelation function (CAF) coordinate plane. Analytical and simulation results show that the proposed method achieves significant performance gain over the conventional detection method under practical scenarios, even with the reduced computational complexity.
    IEEE Communications Letters 01/2014; 18(4):632-635. · 1.16 Impact Factor
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    ABSTRACT: Cooperative spectrum sensing has emerged as a promising solution to the hidden terminal problem in cognitive radio networks (CRNs). It could significantly promote the sensing capability of CRNs by exploiting space diversity gains in a fading environment. However, owing to the decision reporting overhead, there exists a tradeoff between the system throughput and performance of cooperative spectrum sensing. In this paper, we propose a cyclostationarity-based decision reporting scheme for cooperative spectrum sensing in CRNs with cyclic delay diversity orthogonal frequency division multiplexing (CDD-OFDM). Decision information would be embedded into the CDD-OFDM signals in terms of cyclostationary signatures and shared among cognitive radio (CR) users along with data transmissions. As a result, satisfied system throughput could be achieved without additional spectral or temporal resources consumption when the number of cooperative users increases. Numerical results are presented to show the system throughput enhancement.
    Wireless Personal Communications 02/2013; 68(3). · 0.43 Impact Factor
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    ABSTRACT: The energy consumption in radio access network is expected to increase significantly as the network expends to fulfill the explosively growing data traffics. However, when evaluating the energy saving mechanisms, the impact on other performance metrics such as spectral efficiency, should also be taken into account. In this paper, based on the multiple component carrier (CC) feature specified in Long Term Evolution-Advanced (LTE-A) systems, an energy-efficient coordinated scheduling mechanism is proposed to reduce the energy consumption in cellular networks by dynamically switching off CCs and base stations (BS) according to load variations, with special attention on the switching off order and BS transmit power adjustment to maintain service continuity of downlink users. Both the energy and spectral efficiency of the system under the proposed scheduling mechanism are analyzed. Simulation results show that when data traffics are below a quarter of the system capacity, with the proposed scheme more than half of the network power consumption can be saved, while the requirements for user data rate, service continuity, network coverage and spectral efficiency are guaranteed.
    IEEE Journal on Selected Areas in Communications 01/2013; 31(5):959-968. · 3.12 Impact Factor
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    ABSTRACT: Orthogonal frequency division multiplexing signals with cyclic delay diversity (CDD) exhibit distinguishable cyclostationarity that can be used to design cyclostationary signatures for cognitive radio networks. However, such cyclostationary signatures are seriously weakened over doubly-selective fading channels, which consequently causes remarkable performance degradation of cyclostationarity-based detectors. In this paper, we propose a new detector for CDD orthogonal frequency division multiplexing (CDD-OFDM) signals over doubly-selective fading channels. By modelling the doubly-selective fading channel with basis expansion model, we derive the second-order cyclic statistics of the received CDD-OFDM signal in close form. Not only the transmitter-induced cyclostationary characteristics but also the channel-spread cyclostationary features are exploited for sensing CDD-OFDM signals that experience doubly-selective fading. Simulation results indicate that the proposed detector provides substantial performance improvement. Copyright © 2011 John Wiley & Sons, Ltd.
    Transactions on Emerging Telecommunications Technologies. 04/2012; 23(3).
  • Yonglei Jiang, Huaxia Chen, Honglin Hu
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    ABSTRACT: The Cyclic Delay Diversity (CDD)-induced cyclostationary signature is considered to be a robust and cost-efficient scheme for self-coordination of Cognitive Radio Network (CRN). However, the performance of network coordination relies on the reliable detection of such cyclostationary signatures. In this paper, we deduce an exact covariance matrix to characterize the statistics of cyclostationary signature. Based on the covariance matrix, we propose an Asymptotically Optimal Likelihood (AOL) detector for the test of the CDD-induced cyclostationary signature. In addition, an Asymptotically Maximum Likelihood Probability (AMLP) criterion is provided to solve the multiple signatures identification issue. Comprehensive simulations verify that the proposed detector provides superior performance in detection probability and observation duration, compared with the existing Constant False Alarm Rate (CFAR) detector.
    Global Communications Conference (GLOBECOM), 2012 IEEE; 01/2012
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    ABSTRACT: In this paper, using cyclostationarity-based sensing method to detect the presence of Orthogonal Frequency Division Multiplexing (OFDM) signal over doubly-selective fading channels is studied. By approximating the channel with Basis Expansion Model (BEM), we derive the second-order cyclostationary statistics of the received OFDM signal over doubly-selective fading channels. Theoretical analysis indicates that new cyclostationary signatures produced by Doppler spread and multipath delay can be further exploited in the detecting process. Simulation examples demonstrate that the sensing methods using channel-induced cyclostationary features provide substantial improvements on detection performance. Key wordsSignal sensing–Cyclostationarity–Orthogonal Frequency Division Multiplexing (OFDM)–Doubly-selective fading
    Journal of Electronics (China) 01/2011; 28(1):1-7.