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Ping L.,PLA University of Science and Technology | Lu R.,Nanjing Telecommunication Institute
QR2MSE 2013 - Proceedings of 2013 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering | Year: 2013

In this paper, an improved Variable Step-Size Affine Projection Algorithm (VS-APA) is used in adaptive filters for narrowband interference suppression of direct sequence spectrum spreading (DSSS). Compared with traditional VS-APA and NLMS, this algorithm uses exponential function to vary the step-size, which can estimate NBI more accurately and a better tradeoff between performance and complexity. Computer simulations are shown to verify the analyses and compare the performance of the proposed Narrow-band Interference (NBI) suppression scheme with traditional VS-APA and NLMS adaptive algorithm. © 2013 IEEE.

Weng N.,PLA University of Science and Technology | Diao X.,Nanjing Telecommunication Institute | Feng J.,PLA University of Science and Technology | Wang Z.,PLA University of Science and Technology | Chen D.,Chinese Ministry of Water Resources
ICIME 2010 - 2010 2nd IEEE International Conference on Information Management and Engineering | Year: 2010

In distributed heterogeneous scenarios, querying data from various sources efficiently and concisely is always a key challenge. In this paper, we analyze the characteristics of hydrological data and study the data integration in grid environment. We propose a query processing procedure based on domain topics and grid infrastructure. Domain topics are defined according to domain query patterns, and data sources are described for each domain topic. In the following schema mapping procedure, we only focus on a small subset of schemas. A topic query is decomposed into sub-queries against global schema and then mapped to local queries against local schemas in the query processing procedure. Performance metrics are retrieved from grid infrastructure to generate an optimum query plan. And query answers are cached and described as new sources for new queries. Empirical results have shown that our approach works well in the hydrological science grid environment. © 2010 IEEE.

Zhu Y.-Y.,Commanding Communications Academy | Li X.,Commanding Communications Academy | Chen J.-Z.,Nanjing Telecommunication Institute | Zhu Y.-G.,Nanjing Telecommunication Institute
2010 International Conference on Wireless Communications and Signal Processing, WCSP 2010 | Year: 2010

To improve the convergence rate, multiple input vectors are used to update the filter coefficients in the affine projection algorithm (APA) family, however, different input vector affects the convergence differently. The ideal selection criterion of the input vectors is derived by the largest decrease of the mean-square deviation. This selection condition fits for different algorithms of the APA family. Based on the ideal selection criterion, a family of APAs which dynamically select input vectors is presented. The experimental results show that the proposed algorithms have fast convergence speed, small steady-state error compared to the conventional APAs. In addition, the proposed algorithms retain low overall computational complexity. ©2010 IEEE.

Xia B.,Zhenjiang Watercraft College | Wu L.-S.,Shanghai JiaoTong University | Mao J.,Nanjing Telecommunication Institute | Yang L.,Nanjing Telecommunication Institute
Journal of Electromagnetic Waves and Applications | Year: 2014

In this paper, a new quad-band Wilkinson power divider (WPD) is proposed and designed with an analytical method. A quad-band impedance transformer built up by three transmission lines and two loaded shorted-stubs is firstly proposed. The related design equations are deduced by matrix transformation. With proper assumption, a simple analytical design method is presented for the quad-band WPD, and the derived equations and plotted curves can be used for the design. The designed quad-band WPD is an equal power division structure and only one surface-mounted resistor is needed. It has been demonstrated that our proposed WPD possesses simple configuration, small size, low cost, and good performance, i.e. high isolation, low insertion, and return losses, for the quad bands simultaneously from the simulated and measured results. © 2014 Taylor and Francis.

Wang K.,PLA University of Science and Technology | Chen J.,Nanjing Telecommunication Institute | Niu Y.,Nanjing Telecommunication Institute | Zhu Y.,Nanjing Telecommunication Institute
Journal of Networks | Year: 2013

To estimate the wideband or multi-channel signals' spectrum swiftly and exactly is a key technology to improve the performance of wideband spectrum sensing. The paper was proposed a novel spectrum estimation algorithm based on compressed sensing (CS) and multitaper method (MTM), which is called CS-MTM. The new algorithm was validated by single-tone, multi-tone and QPSK signals. Meanwhile, the paper has validated six common random meaurement matrixes which can be used in compressed spectrum estimation algorithm successfully. Simulation results show that the proposed approach can potentially achieve better performance than multi-taper method combined with singular-value decomposition based on compressed sensing(CS-MTM-SVD) in complexity, accuracy and real-time property. © 2013 ACADEMY PUBLISHER.

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