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Characterizing Ultra-wide Band indoor line-of-sight wireless channel

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Journal of Systems Engineering and Electronics 2007年第4期18卷 673-678,697页

作者： Wang Yang zhang naitong zhang Qinyu zhang Zhongzhao Communication Research Center Harbin Institute of Technology Harbin 150001 P. R. China

By exploring the deterministic characteristics of the measurement data, a new propagation model with two deterministic clusters and stochastic arriving rays within each cluster is proposed. When considering the cumulative distribution function （CDF） of the three key channel statistics, the proposed model fits the measurement data better than SV/IEEE 802.15.3, a model which is known as a standard model for UWB indoor propagation channel. Therefore, with the additional knowledge of the specific environment geometry, the proposed model generating impulse responses ＂resemble＂ the measured channel impulse responses better than IEEE model. Moreover, the proposed model＇s parameters obtaining procedure is simplified by utilizing simple parameters of the environment.

关键词： UWB wireless channel propagation characteristic indoor channel.

Deterministic simulation of UWB indoor propagation channel

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Journal of Systems Engineering and Electronics 2008年第3期19卷 447-452页

作者： Wang Yang zhang naitong zhang Qinyu zhang Zhongzhao Communication Engineering Research Center Harbin Inst. of Technology Shenzhen Graduate School Shenzhen 518055 P. R. China Communication Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

A site-specific model of UWB pulse propagation in indoor environment is addressed. The simulation utilizes the principles of geometrical optics （GO） for direct and reflected paths＇ tracing and the time domain technique for describing the transient electromagnetic field reflected from wall, floor, ceiling, and objects. The polarization of the received waveform is determined by taking into account the radiation pattern of the transmitting and receiving antennas, as well as the polarization changes owing to every reflection. The model provides more intrinsical interpretations for UWB pulse propagation in realistic indoor environment.

关键词： UWB time domain indoor propagation channel diffraction.

Deconvolution techniques for characterizing indoor UWB wireless channel

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Journal of Systems Engineering and Electronics 2008年第4期19卷 688-693页

作者： Wang Yang zhang naitong zhang Qinyu zhang Zhongzhao Communication Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

A deconvolution algorithm is proposed to account for the distortions of impulse shape introduced by propagation process. By finding the best correlation of the received waveform with the multiple templates, the number of multipath components is reduced as the result of eliminating the ＂phantom paths＂, and the captured energy increases. Moreover, it needs only a single reference measurement in real measurement environment （do not need the anechoic chamber）, which by far simplifies the templates acquiring procedure.

关键词： ultra-wide band channel model CLEAN algorithm CIR deconvolution.

Simplified calculation of UWB signal transmitting through a finitely conducting slab

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Journal of Systems Engineering and Electronics 2008年第6期19卷 1070-1075页

作者： Wang Yang zhang naitong zhang Qinyu zhang Zhongzhao Communication Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

A simplified closed-form analytic solution for UWB impulse signal transmitting through a finitely conducting slab is proposed. The approach first requires evaluating the impulse response of the slab and then convolving it with the specified incident field waveform. To obtain the impulsive transmitting field, either for vertical or horizontal polarization, approximations to the refraction coefficients and propagation loss are made, which can be proved to be accurate enough, comparing with their frequency domain solutions. Thereby, it permits simplified closed-form expressions in the time domain for both terms. The resulting transient response for the transmitting impulse field is then given by convolution of the time domMn refraction coefficients and time domain propagation loss. A numerical example of an incident monocyele transmitting through a slab using this technique, is presented, to illustrate the effective use of the method.

关键词： ultra-wide band time domain indoor propagation channel multipath.

Performance analysis of an indoor UWB ranging system

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Journal of Systems Engineering and Electronics 2009年第3期20卷 450-456页

作者： zhang Tingting zhang Qinyu zhang naitong Xu Hongguang School of Electrical and Information Harbin Inst. of Technology Harbin 150001 P. R. China Harbin Inst. of Technology Shenzhen Graduate School Shenzhen 518055 P. R. China

To evaluate the ranging performance of impulse radio ultra wideband （IR-UWB） signals, an experiment is performed in a typical indoor environment. In order to mitigate the ranging error caused by theoretical algorithm and practical circuits, one way-time difference of the arrival （OW-TDOA） ranging method and corresponding approaches are proposed and carried out according to the structure of UWB transceivers. Generalized maximum likelihood （GML） estimator based on energy detection is applied for the time of arrival estimation. The obtained results show that this UWB ranging system can achieve a relative high ranging accuracy in a multipath environment （e.g. about 5 cm at ranges up to 6 m）, which is practical and meaningful for many sensor applications.

关键词： ranging impulse radio ultra wideband time of arrival energy detection multipath

BER analysis of STBC hybrid carrier system based on WFRFT with frequency domain equalization

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Science China(Information Sciences) 2018年第8期61卷 147-159页

作者： Zhenduo WANG Lin MEI Xuejun SHA naitong zhang Communication Research Center Harbin Institute of Technology Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory

The inherent characteristic of hybrid carrier(HC) scheme based on the weighted-type fractional Fourier transform(WFRFT) is revealed. The proposed linear combination of single carrier(SC) and multicarrier’s(MC) characteristics is helpful to balance the conflicting requirements and achieve the comparative analysis of SC/MC. As an example, analytical SER/BER expressions of HC system with zero forcing(ZF)and minimum mean square error(MMSE) equalization are derived. In addition, the derived BER expressions are extended to multi-input systems. A unified framework of space time block code(STBC) HC scheme is proposed with two WFRFT modules at the transmitter or receiver, where STBC-SC and STBC-MC systems are the special cases of the novel structure.

关键词： single carrier multi-carrier weighted-type fractional Fourier transform hybrid carrier zero forcing minimum mean square error space time block code

Partial intersection sphere decoding with weighted voting for sparse rotated V-OFDM systems

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Science China(Information Sciences) 2018年第2期61卷 77-89页

作者： Qi FENG Xiang-Gen XIA naitong zhang School of Electronic Science and Engineering Nanjing University College of Information Engineering Shenzhen University Department of Electrical and Computer Engineering University of Delaware School of Electronics and Information Engineering Harbin Institute of Technology

Vector orthogonal frequency division multiplexing(V-OFDM) is a general system that builds a bridge between OFDM and single-carrier frequency domain equalization in terms of intersymbol interference level and receiver complexity. In this paper, we focus on a rotated V-OFDM system over a broadband sparse channel owing to its large time delay spread and fewer nonzero taps. In order to collect the multipath diversity,a simple rotation matrix is designed, independent of the number of subchannels at the transmitter. For the rotated V-OFDM receiver, a partial intersection sphere decoding with weighted voting method is proposed by exploiting the sparse nature of the multipath channel. The proposed receiver chooses the transmitted vector from the set with the maximum likelihood estimation generated using the partial intersection sphere decoding method. For an extreme case, such as when a candidate set is empty, which usually occurs at a low signal-to-noise ratio(SNR), an efficient weighted voting system is used to estimate the transmitted vectors symbol-by-symbol. Simulation results indicate that the proposed receiver improves the symbol error rate performance with reduced complexity, especially for low SNR scenarios.

关键词： vector orthogonal frequency division multiplexing sparse multipath channel partial intersection sphere decoding weighted voting diversity order

Resource allocation based on subcarrier exchange in multiuser OFDM system

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Science China(Information Sciences) 2013年第1期56卷 184-197页

作者： WANG Ye zhang QinYu zhang naitong Harbin Institute of Technology Shenzhen Graduate School Communication Engineering Research Center Harbin Institute of Technology Communication Research Center

Multi-user orthogonal frequency division multiplexing(OFDM) is one of the most important techniques for next-generation wireless communication *** sum capacity and proportional fairness index are two important metrics in OFDM adaptive resource *** existing researches,the two metrics have individually yielded approximately optimal ***,as the two goals seem to contradict each other,it means that they cannot achieve optima *** paper presents a resource allocation algorithm based on subcarrier *** relaxing the fairness index,the proposed algorithm can dynamically adjust the fairness ***,By considering a criterion that minimizes the loss of sum capacity,the proposed algorithm can balance the tradeoff between fairness and sum *** contrast to existing algorithms,our proposal improves performance by approximately 30% in terms of sum capacity,at the expense of approximately 10% reduction in proportional ***,if a malicious user exists,each user in the system can obtain higher ergodic capacity compared with the conventional *** decrease the complexity,a low-complexity simplified alternative is presented,which outperforms the conventional algorithm with an increase in the number of *** numerical simulations are carried out to verify the efficiency and ***,we discuss in detail the computational complexity of the proposed algorithm.

关键词： multiuser OFDM resource allocation capacity proportional fairness computational complexity

IDMA based MAI mitigation scheme with low complexity and low latency

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Journal of Systems Engineering and Electronics 2012年第6期23卷 791-801页

作者： Zuoliang Yin Xingpeng Mao Jun Cai naitong zhang School of Electronics and Information Engineering Harbin Institute of Technology Harbin 150001 R R. China Department of Computer and Electrical Engineering University of Manitoba Winnipeg R3T 5V6 Canada

High complexity and high latency are key problems for multiuser detection （MUD） to be applied to a mobile station in cellular networks. To tackle these problems, an interleave division multiple access （IDMA） based multiple access scheme, grouped spread IDMA （GSIDMA）, is proposed. In a GSIDMA system, lower complexity and latency for mobile stations can be achieved by appropriately dividing active users into different groups. The system model of GSIDMA is constructed and followed by analysing on its system capacity, complexity and latency, and bit error rate （BER） performance. The extrinsic information transfer （EXIT） chart is used to analyze the convergence behavior of the iteration process. The grouping method and interleavers-reuse issue for GSIDMA are also discussed preliminarily. The analyses and simulation results indicate that the complexity and latency of the proposed scheme are much lower than those of IDMA, whereas its BER performance is close to the latter. The properties of low complexity and low latency make it more feasible for the practical implementation.

关键词： grouped spread interleave division multiple access(GSIDMA) iterative multiuser detector (IMUD) low complexity lowlatency multiple access interference (MAI) mitigation.