Table of Content

30 May 2012, Volume 30 Issue 3

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Communication Engineering

Energy-Efficient Distributed Relay Selection Based on Statistical Channel State Information

JIANG Hai-fang, ZHANG Si-hai, ZHOU Wu-yang

2012, 30(3):  221-226.  doi:10.3969/j.issn.0255-8297.2012.03.001

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In this paper, we propose a distributed relay selection algorithm based on statistical channel state information (CSI) in amplify-and-forward (AF) cooperative networks. A tradeoff is made between energy efficiency and system outage performance. A forwarding threshold is obtained by minimizing the average total power consumption. Each relay individually decides whether to participate in forwarding the source signals according to a forwarding threshold. A distributed multiple relay selection (DMRS) algorithm is proposed, in which all candidate relays have the possibility of forwarding the signals and the threshold is obtained by numerical search. The DMRS algorithm obtains good outage performance with low power consumption.
A distributed single relay selection (DSRS) algorithm with low complexity is then investigated under the assumption that only one relay forwards the signals. Simulation results indicate that the proposed algorithms provide significant performance gain in terms of energy efficiency over the existing AF relay selection algorithms.

Cross-Layer Optimization for Wireless Mesh Network with Multi-packet Reception

SHI Lei1, HAN Jiang-hong1, SHI Yi2, WEI Zhen-chun1

2012, 30(3):  227-233.  doi:10.3969/j.issn.0255-8297.2012.03.002

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Multi-packet reception (MPR) technique can effectively increase throughput of wireless networks.We establish a suitable cross-layer design model for a wireless mesh network. It is a mixed integer programming model, which cannot be solved within polynomial time in general. We then propose a near-optimal solution to be solved in polynomial time. In this solution, integer variables are released into the space of a real number field,
and the original mixed integer programming model becomes a linear programming model. We can obtain the near-optimal solution by iteration. Compared with optimal solutions without MPR, we show that throughput is increased by about 300% when using MPR.

Low-Complexity Probability Generation Algorithm for Stochastic Decoding of Non-binary LDPC Codes

PANG Bao-mao1;2, SHI Hao-shan1, HE Guang-hua3

2012, 30(3):  234-238.  doi:10.3969/j.issn.0255-8297.2012.03.003

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Stochastic decoding algorithms for non-binary LDPC codes have good performance, but high computational complexity in probability generation. In this paper, we propose a simple method for fast generation of the probability, especially in high-order modulation schemes. The algorithm calculates probability using the quantized Euclidean distances between constellation points and the received signal points. It can avoid the probability calculation for all constellation points and the arithmetic of powers. Simulation results show that the proposed algorithm has low complexity and incurs less performance degradation, which is advantageous in hardware implementation.

Modeling and Analysis of Survivability of IP Multimedia Subsystem Based on SPN

ZHAO Ming-feng1;2, ZHOU Ya-jian2, REN Dong-xiao1, YANG Yi-xian1;2

2012, 30(3):  239-244.  doi:10.3969/j.issn.0255-8297.2012.03.004

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As one of network and business integration standard, IP multimedia subsystem (IMS) plays an important role in network convergence. It is important to analyze the authentication and registration process, and build a survivability model for IMS. Having defined survivability and its attributes, this paper proposes a survivability stochastic Petri net (SPN) model and its simplified version, and analyzes the survivability attributes including reliability, maintainability and availability. Simulation results show that the measures of survivability vary with time, failure rate and repair rate, respectively. Reliability is reduced with the increase of time and failure rate, and maintainability enhanced with the increase of time and repair rate. This study
provides useful clue for improving survivability of IMS systems.

Mie Scattering in Ultraviolet Communication

HE Hua, KE Xi-zheng

2012, 30(3):  245-250.  doi:10.3969/j.issn.0255-8297.2012.03.005

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Aerosols contributes much to the ultraviolet non-line-of-sight communication. Based on the Mie theory, this paper derives recurrence functions of Mie scattering coefficient and angle scattering coefficient, and uses the recurrence functions to compute the ultraviolet scattering phrase function. The results show that the larger the scattering particle radius, the stronger the forward and backward scattering effects. When scattering particles are smaller, ultraviolet forward scattering is weaker than back scattering, and the range of phrase function is not large. However, when scattering particles become larger, the ultraviolet forward scattering is much stronger than scattering in the backward and other directions.

 

Signal and Information Processing

Acoustic Feedback Cancellation Based on Parallel Gradient Projection in Hearing Aids

LIANG Rui-yu1;3, ZHAO Li3, WANG Qing-yun2, XI Ji1, ZHANG Xue-wu1

2012, 30(3):  256-262.  doi:10.3969/j.issn.0255-8297.2012.03.007

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 Adaptive feedback cancellation is an effective way to suppress echo howling in hearing aids. However,when the external input signal is correlated with the receiver input signal, the estimate of the feedback path contains a large error. This paper proposes a linear prediction-parallel gradient projection algorithm,which generates a FIR filter to obtain the decorrelation signal by linear prediction of the output signals. The decorrelation signal is then used to build a convex optimization equation. With the parallel gradient projection algorithm, the equation is solved to evaluate the echo path. Simulation results show clear improvement in convergence, stability and precision.

Tracking a Variable Number of Targets in Cluttered Environment

WU Hao, SU Wei-min, GU Hong

2012, 30(3):  263-269.  doi:10.3969/j.issn.0255-8297.2012.03.008

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In this paper, a passive bistatic radar system using television as opportunistic illuminator is presented. When considering the existence of clutters, a new method is proposed to track a variable number of targets in a cluttered environment. A clustering algorithm is first introduced to judge whether a new target appears or an existing target vanishes, and then the UKF based cheap joint probabilistic data association method (UKFCJPDA) is used to track the targets. Numerical simulation shows good performance of this algorithm.

Joint 2D-DOD and 2D-DOA Estimation in Bistatic MIMO Radar

XU Ling-yun, ZHANG Xiao-fei, XU Zong-ze

2012, 30(3):  270-274.  doi:10.3969/j.issn.0255-8297.2012.03.009

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A new algorithm for multi-angle estimation in bistatic MIMO radar with an L-shaped array is presented. According to the characteristics of received signals, different cost functions are constructed. The transmitting and receiving array matrices are obtained using an iterative least square algorithm. Using a structure of L-shaped array and the least square method, the 2D-DOA and 2D-DOD of multi-target involved in the receiving array from the target to the transmitter and receiver can be estimated based on the decomposed matrices. The method does not need to search spectral peaks or pair parameters. In comparison with the ESPRIT method, the proposed algorithm has high precision in the parameter estimation, which is close to the
Cramer-Rao bound. It can works well in small sizes. Simulation results verify its effectiveness.

Gaussian Noise Reduction with Tetrolet and Active Random Field Model

WANG Rui-ling, SHI Jun

2012, 30(3):  275-280.  doi:10.3969/j.issn.0255-8297.2012.03.010

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In this study, an image denoising algorithm is proposed by combining Tetrolet transform and active random field (ARF). An image with Gaussian noise is decomposed with Haar wavelets, and the ARF algorithm is used to reduce Gaussian noise in the wavelet domain. After inverse wavelet transform, the Tetrolet transform is used for further denoising. The proposed method is compared with other denoising algorithms including wavelet algorithm, Tetrolet algorithm, Markov random field based algorithm and ARF based algorithm. Experimental results indicate that the proposed approach can effectively reduce Gaussian noise at various levels, and achieve better results than other algorithms.

Zero-Norm Sparse Coding in Face Recognition

LANG Li-ying, XIA Fei-jia

2012, 30(3):  281-286.  doi:10.3969/j.issn.0255-8297.2012.03.011

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To avoid conflict between algorithmic efficiency and recognition effectiveness in face recognition,this paper proposes a zero-norm sparse coding algorithm. The algorithm uses zero-norm to describe sparsity of a sparse coding model and applies a strategy of continuous extension of discontinuity points to speed convergence. A test based on the ORL database show that the algorithm is more efficient in adjusting sparsity so that the computation time is reduced, and gives higher recognition rate as compared with the methods of nonnegative sparse coding and non-negative matrix factorization with sparseness constraints.

Molecular Classification of Acute Leukemia Using EHW with Filter-Based Gene Selection

WANG Jin1;3, DING Ling1, SUN Kai-wei1, LEE Chong-ho2

2012, 30(3):  287-293.  doi:10.3969/j.issn.0255-8297.2012.03.012

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A virtual reconfigurable architecture-based intrinsic evolvable hardware (EHW) is proposed for the molecular classification of cancer. To efficiently process DNA microarray datasets and cooperate with the hardware realization of EHW, five different filter-based gene selection methods are compared and discussed in this paper. The EHW classification system handles the selected informative genes through two stages: system
learning and system classification. Empirical studies on a human acute leukemia dataset demonstrate that classification accuracy of the gene selection scheme based on signal-to-noise ratio outperforms its competitors. Classification accuracy of the proposed EHW is high comparable with other state-of-the-art pattern recognition methods. The system recognition time is reduced to 0.12 ms.

Passive Ranging of Small Infrared Target in Airborne Reconnaissance

FU Xiao-ning1, WANG Jie1, REN Bao-wen2

2012, 30(3):  294.  doi:10.3969/j.issn.0255-8297.2012.03.013

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 To overcome the problems in passive ranging of infrared small targets used in photoelectric countermeasure
systems, a passive ranging scheme is proposed based on the distance-ratio between two adjacent
sampling times and the direction information about the azimuth and pitch angles of the target. A model of
motion is build to describe the relative position between the observer and the target in a 3D space. With
this model, a quadratic equation is derived, whose parameters can be calculated by using the distance-ratio,
the 3D coordinates of the observer, and the azimuth and pitch angles of the target. The proposed method
has a simple form, and can avoid the occurrence of near-zero values in the denominator. The performance is
demonstrated by simulation. It is applicable to the estimation of the target distance with a dual-band infrared
detection system installed on an airborne or missile-borne platform.

Electronic Engineering

Dynamical Coarse-Grained Partially Reconfigurable Face Detection

XIAO Jian1;3, LIU Bo1, MEI Chen1, ZHU Min2, YANG Jun1, LIU Lei-bo2, WEI Shao-jun

2012, 30(3):  299-305.  doi:10.3969/j.issn.0255-8297.2012.03.014

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Face detection system needs to meet a variety of constraints in embedded environments, but the high computational/control intensive features make the real-time implementation difficult. This paper presents a face detection system based on a dynamical coarse-grained partially reconfigurable platform called “REMUSII”. The cascade AdaBoost-based detection algorithm is divided into several non-consecutive sub-tasks. Mailbox
scheduling, configuration flow and data flow optimization methods improve the instruction-level and task-level parallelism. Experiment results show that this approach with a 200 MHz clock can process about 17 frames per second on 640£480 images. Its detection rate is over 95%. The system consumes about 194 mW, and its area is about 24 mm2 in TSMC’s 65 nm logic process.

High-Speed Arbitrarily Distributed Pseudo-random Number Generator Based on FPGA

LIU Pei-hua1, LU Hua-xiang1, GONG Guo-liang1, LIU Wen-peng1, CHEN Tian-xiang2

2012, 30(3):  306-310.  doi:10.3969/j.issn.0255-8297.2012.03.015

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 Acceptance-rejection is a widely used method to generate arbitrarily distributed pseudo-random numbers from uniformly distributed pseudo-random numbers. This paper proposes a method to improve accepting efficiency. The method transforms samples that are discarded in the original method into acceptable ones to improve efficiency. With the improved acceptance-rejection method, an arbitrarily distributed pseudo-random number generator is designed, which uses a linear feedback shift register to produce uniformly distributed pseudo-random numbers, and then uses the improved acceptance-rejection scheme to generate arbitrarily distributed pseudo-random numbers. The design is implemented on FPGA. The experimental results show that the design has high output efficiency and wide applicability.

Control and System

Application of Dual Quaternion in Spacecraft Relative Navigation

LI Jing1, WANG Hui-nan2, LIU Hai-ying3

2012, 30(3):  311-316.  doi:10.3969/j.issn.0255-8297.2012.03.016

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To improve accuracy and real-time performance in relative positioning and measurement of attitude
information meterage of spacecraft, a dual quaternion model is introduced. The method described combines
relative rotation and translation between target spacecrafts and the spacecraft tracing coordinates. It uses a
spiral vector method to calculate the renovated dual quaternion. A camera survey model is constructed to
measure the relative position and attitude of the spacecraft. The extended Kalman filter (EKF) is used to
eliminate noise jamming caused in the state updating and the measurement processes. Simulation results show
that the navigation algorithm satisfies the precision requirements of spacecraft relative navigation.

Route Planning in Low Altitude Penetration for Cruise Missile Based on a Hybrid Particle Swarm Optimization

WANG Jian-qing, LI Fan, ZHAO Jian-hui

2012, 30(3):  317-323.  doi:10.3969/j.issn.0255-8297.2012.03.017

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 A hybrid planning algorithm PSO-SA is presented, which is an integration of the simulated annealing algorithm (SA) and the particle swarm optimization (PSO) algorithm. PSO-SA is used to evaluate the optimal fitness value generated by PSO. PSO-SA used in route planning of cruise missile can avoid the common defect of premature convergence, accomplish the static and dynamic route planning assignment quickly, and
produce an ideal 3-D flight path. Simulations demonstrate feasibility of the algorithm. Compared to PSO, PSO-SA achieves a shorter range in the same initial locations, thus, cruise missiles consume less fuel.

Geometric Design and Shape Adjustment for Developable B-Spline Surfaces with Multiple Shape Parameters

HU Gang1;2, JI Xiao-min1, QIN Xin-qiang2

2012, 30(3):  324-330.  doi:10.3969/j.issn.0255-8297.2012.03.018

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 To solve the problems in adjusting and controlling shapes of developable surfaces, two explicit and efficient methods of computer-aided design for developable surfaces with multiple local shape parameters are proposed. A class of novel quasi-B-spline basis functions with two shape parameters is presented to construct Bspline curves with multiple shape parameters, which is an extension of the classical cubic uniform B-spline basis
functions. Following the idea of duality between points and planes in 3D projective space, the corresponding developable quasi-B-spline surfaces with multiple shape parameters are represented using control planes with quasi-B-spline basis functions. The developable quasi-B-spline surfaces inherit the outstanding properties of the B-spline surfaces, with good performance in adjusting the local shapes by changing the two shape parameters. In the particular case where shape parameters are both equal to 1, the developable quasi-B-spline surface is a developable B-spline surface. In addition, some properties of the developable quasi-B-spline surfaces and applications in developable surfaces design are discussed. Modeling examples illustrate that the developable quasi-B-spline surfaces provide two valuable ways for the design of developable surfaces.