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Wang Y.,National Key Laboratory of Blind Signals Processing | He L.,National Key Laboratory of Blind Signals Processing
Proceedings - 2014 IEEE Workshop on Advanced Research and Technology in Industry Applications, WARTIA 2014 | Year: 2014

Estimating network topology is a non-trivial task. Different from the state-of-art methods such as traceroute-like active probing, network tomography and network protocols analysis based passive measurement, this work proposes a novel method to estimate the network hidden topology using time to live (TTL) values extracted from IP packets. TTL contains the information about hops of the forward paths which can be fused to reconstruct the topology. The proposed estimating algorithm is described and its performance is illustrated using topology simulation data. Experimental results demonstrate the effectiveness of the newly developed technique. © 2014 IEEE.

Liu C.-G.,National Key Laboratory of Blind Signals Processing | Li L.-Z.,National Key Laboratory of Blind Signals Processing
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2012

The effects of carrier frequency offset on cross-correlation based timing algorithm were analyzed theoretically and an improved timing algorithm was proposed. The new method was neither sensitive to frequency offset nor dependable on the concrete preamble structure. Then, the distribution performances of the expectations and variances of the newly proposed timing metric were analyzed over different wireless channels through Monte-Carlo simulations. The algorithm was applied in IEEE 802.16d system and simulations were carried out. The simulation results show that the new method is less sensitive to frequency offset, and the timing effect is very accurate. © copyright.

Xin J.-R.,National University of Defense Technology | Xin J.-R.,National Key Laboratory of Blind Signals Processing | Lu L.-X.,National Key Laboratory of Blind Signals Processing | Bao X.,National Key Laboratory of Blind Signals Processing | Cheng J.,National Key Laboratory of Blind Signals Processing
Tien Tzu Hsueh Pao/Acta Electronica Sinica | Year: 2014

Noise estimation is the basis of the adaptive blind signal detection. It provides the thresholds of automatic detector based on the CFAR (Constant False Alarm Rate) rule. The traditional noise estimator was complicated and cannot be easily implemented in the on-line blind signal processing system for the satellite broadband frequency-hopping signal. Utilizing the sparseness of the frequency-hopping signal, a new algorithm was proposed to facilitate the noise estimation. The reliability and complexity of the algorithm was analyzed theoretically, and the effectiveness was verified through both simulations and real signal experiments. Compared to the classical algorithm, the proposed algorithm can provide similar noise estimation results, while its computational complexity and buffer consumption was significantly reduced. ©, 2014, Tien Tzu Hsueh Pao/Acta Electronica Sinica. All right reserved.

Zhao Y.,Zhengzhou University | Zhao Y.,National Key Laboratory of Blind Signals Processing | Luo S.-E.,National Key Laboratory of Blind Signals Processing | Wan J.,National Key Laboratory of Blind Signals Processing
International Conference on Signal Processing Proceedings, ICSP | Year: 2010

In the broadband communication systems, signals in intermediate frequency (IF) bandwidth usually have nonequal bandwidths and arbitrary carriers. The channelization architecture based on subband filterbanks is an efficient realization method to channelization these signals. The performance analysis of this channelization architecture is proposed in this paper. A channelization structure using complex-valued subband filterbanks is given out firstly, and the mathematic model of this structure is established. Then the channelization process is deduced theoretically and the expressions of channelization results are obtained. These expressions are divided into some addition terms, the error causations can be attained by analyzing these addition terms. Three error parameters are defined to describe different kinds of distortions. Simulations are carried out under the given channelization structure, and the results demonstrate the rationality of the deduction conclusions. This performance analysis method are also helpful on designing the optimal subband filterbanks for channelization. © 2010 IEEE.

Yuan X.-H.,National Key Laboratory of Blind Signals Processing | Zhang G.-G.,National Key Laboratory of Blind Signals Processing | Zheng H.,National Key Laboratory of Blind Signals Processing
2012 IEEE International Conference on Information and Automation, ICIA 2012 | Year: 2012

This paper analyzes the effect of large scale ionospheric tilts on the errors of single site location by establishing a simplified model for large scale ionospheric tilts in a three-dimensional coordinate. An equation including the coordinate of the reflection point and a numerical resolution to the equation based on Newton-Raphson iterative algorithm are given. Then the curves of error of single site location versus tilts angle, direction and target range is given by simulations. © 2012 IEEE.

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