This paper proposes an unequal error protection（UEP）coding method to improve the transmission performance of three-dimensional（3D）audio based on expanding window fountain（EWF）.Different from other transmissions ...This paper proposes an unequal error protection（UEP）coding method to improve the transmission performance of three-dimensional（3D）audio based on expanding window fountain（EWF）.Different from other transmissions with equal error protection（EEP）when transmitting the 3D audio objects.An approach of extracting the important audio object is presented,and more protection is given to more important audio object and comparatively less protection is given to the normal audio objects.Objective and subjective experiments have shown that the proposed UEP method achieves better performance than equal error protection method,while the bits error rates（BER）of the important audio object can decrease from 10^（–3） to 10^（–4）,and the subjective quality of UEP is better than that of EEP by 14%.展开更多
The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply Thetooth surface equation of EBCBG manufactured by end milling cutter with involute profile is de-rived. The tooth form error is analy...The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply Thetooth surface equation of EBCBG manufactured by end milling cutter with involute profile is de-rived. The tooth form error is analyzed on the basis of spherical involute展开更多
This paper evaluates the effect of decision feedback equalizer( DFE) error propagation for400 Gb/s Ethernet( 400 GbE) electrical link in order to propose some effective methods to improve bit error rate( BER). First,a...This paper evaluates the effect of decision feedback equalizer( DFE) error propagation for400 Gb/s Ethernet( 400 GbE) electrical link in order to propose some effective methods to improve bit error rate( BER). First,an analytical model for DFE burst error length distribution is proposed and simulated based on a NRZ electrical link in which a 5-tap DFE combined with a multiple-tap feed forward equalizer( FFE) is included. Then,a detailed derivation for BER considering DFE error propagation is given based on the distribution of burst error run length and the BER performance with and without forward error correction( FEC) is simulated too. After that,this paper investigates several MUX-based FEC interleaving methods including their complexity and latency in order to improve BER further. At last,three FEC interleaving schemes are compared not only in interleaving gain,but also in hardware complexities and latencies. Simulation results show that pre-interleave bit muxing can obtain good tradeoff between BER and complexity for 400 Gb E electrical link.展开更多
The achievable bit error rate of a linear equalizer is crucially determined by the choice of a decision delay parameter. This brief paper presents a simple method for the efficient determination of the optimal decisio...The achievable bit error rate of a linear equalizer is crucially determined by the choice of a decision delay parameter. This brief paper presents a simple method for the efficient determination of the optimal decision delay parameter that results in the best bit error rate performance for a linear equalizer. Keywords Linear equalizer - decision delay - bit error rate Eng Siong Chng received his university education at the University of Edinburgh, Edinburgh, Scotland (BEng 1991, PhD 1995). After his PhD, he spent 6 months in Japan, working as a researcher for Riken. After working in industry in Singapore for 7 years, he joined the School of Computer Engineering, Nanyang Technological University in 2003. His research interests are in digital signal processing for communication applications, speech and handwriting recognition and noise reduction.Sheng Chen obtained a BEng degree in control engineering from the East China Petroleum Institute, Dongying, China, in 1982, and a PhD degree in control engineering from the City University at London in 1986. He joined the School of Electronics and Computer Science at the University of Southampton in September 1999. He previously held research and academic appointments at the Universities of Sheffield, Edinburgh and Portsmouth. Dr Chen is a Senior Member of the IEEE in the USA. His recent research works include adaptive nonlinear signal processing, modeling and identification of nonlinear systems, neural networks and machine learning, finite-precision digital controller design, evolutionary computation methods and optimization. He has published over 200 research papers. In the database of the world’s most highly cited researchers in various disciplines, compiled by the Institute for Scientific Information (ISI) of the USA, Dr Chen is on the list of highly cited researchers in the category that covers all branches of engineering subject, see www.ISIHighlyCited.com.展开更多
This work proposes an improved inertia weight update method and position update method in Particle Swarm Optimization (PSO) to enhance the convergence and mean square error of channel equalizer. The search abilities o...This work proposes an improved inertia weight update method and position update method in Particle Swarm Optimization (PSO) to enhance the convergence and mean square error of channel equalizer. The search abilities of PSO are managed by the key parameter Inertia Weight (IW). A higher value leads to global search whereas a smaller value shifts the search to local which makes convergence faster. Different approaches are reported in literature to improve PSO by modifying inertia weight. This work investigates the performance of the existing PSO variants related to time varying inertia weight methods and proposes new strategies to improve the convergence and mean square error of channel equalizer. Also the position update method in PSO is modified to achieve better convergence in channel equalization. The simulation presents the enhanced performance of the proposed techniques in transversal and decision feedback models. The simulation results also analyze the superiority in linear and nonlinear channel conditions.展开更多
针对正交时频空(Orthogonal Time Frequency Space, OTFS)调制系统中均衡器性能不佳及线性滤波器复杂度较高等问题,提出了一种LU(Lower-Upper)分解与迭代最小均方误差(Iterative Minimum Mean Square Error, IMMSE)均衡器结合的OTFS系...针对正交时频空(Orthogonal Time Frequency Space, OTFS)调制系统中均衡器性能不佳及线性滤波器复杂度较高等问题,提出了一种LU(Lower-Upper)分解与迭代最小均方误差(Iterative Minimum Mean Square Error, IMMSE)均衡器结合的OTFS系统信号检测算法(LU-IMMSE)。该算法依据时延多普勒域稀疏信道矩阵的特征,采用一种低复杂度的LU分解方法,以避免MMSE均衡器求解矩阵逆的过程,在保证均衡器性能的前提下降低了均衡器复杂度。在OTFS系统中引入一种IMMSE均衡器,通过不断迭代更新发送符号均值和方差这些先验信息来逼近MMSE均衡器最优估计值。LU-IMMSE算法通过调节迭代次数可以有效降低误比特率。在比特信噪比为8 dB时,5次迭代后的LU-IMMSE均衡器误比特率相比传统的MMSE均衡器降低了约11 dB。随着迭代次数的增大,较传统IMMSE算法降低了计算复杂度。在最大时延系数为4、符号数为16的情况下,与直接求逆相比,所提出的低复杂度LU分解方法降低了约91.72%的矩阵求逆计算复杂度。展开更多
信道仿真器中不同通道之间的幅相不一致会使系统性能恶化,通常的解决方法是在接收信道中加入校准均衡器,以校正信号传输路径中的幅度和相位失真。为了降低通道间的幅相误差、提高信道均衡效果,文中设计了一种正则化交替频域最小二乘优...信道仿真器中不同通道之间的幅相不一致会使系统性能恶化,通常的解决方法是在接收信道中加入校准均衡器,以校正信号传输路径中的幅度和相位失真。为了降低通道间的幅相误差、提高信道均衡效果,文中设计了一种正则化交替频域最小二乘优化算法(Regularized Alternating Frequency Domain Least Squares Optimization,RA-ALO)。该算法采用正则化来确保矩阵求逆时解的正确性,并使用交替最小二乘法(Alternating Least Squares,ALS)寻找最优解来增强均衡器性能。仿真结果表明,在信道均衡方面,与正则化算法和求伪逆算法相比,该算法具有更低的幅相误差、更优的校准性能。展开更多
由于卫星通信系统中高功率放大器的非线性失真与多径信道的线性衰落效应相互耦合会引发传输性能恶化问题,而传统的盲均衡算法(如恒模算法)虽在应对多径引起的线性符号间干扰时具有一定效果,但无法有效补偿高阶调制信号中的非线性失真,...由于卫星通信系统中高功率放大器的非线性失真与多径信道的线性衰落效应相互耦合会引发传输性能恶化问题,而传统的盲均衡算法(如恒模算法)虽在应对多径引起的线性符号间干扰时具有一定效果,但无法有效补偿高阶调制信号中的非线性失真,尤其是在没有训练序列的盲均衡场景下,传统方法难以提供足够的监督信息.为了克服这一挑战,本文提出一种基于判决重构的非线性卫星信道盲均衡算法(blind Equalization Algorithm for Nonlinear satellite channels based on Decision-Reconstruction,DR-NEA),DR-NEA采用判决-插值-重构模式生成参考信号,从而实现无监督条件下的非线性与线性失真联合补偿.首先,算法通过恒模算法对接收到的信号进行线性均衡,消除多径效应引起的线性失真.随后,通过判决、插值和重构生成参考信号,该参考信号为非线性均衡器参数辨识提供监督信息.最后,DR-NEA使用拟牛顿法在最小均方误差准则下对Wiener型均衡器的参数进行辨识,进而实现对信道中的线性与非线性失真联合补偿.仿真结果表明,在高阶调制模式(32APSK、32QAM、64QAM)下,DR-NEA相较于传统线性均衡算法,显著提升了性能,在误码率为1×10-3时,较传统线性均衡算法性能增益超4 dB,体现了该算法在高阶调制下较强的非线性补偿能力.此外,当判决误码率低于9.44%时,DR-NEA依旧保持稳定且输出性能几乎不受影响,进一步验证了本文算法的鲁棒性.DR-NEA通过创新性地引入基于判决重构的参考信号生成方法,解决了传统盲均衡算法无法提供足够监督信息的问题.同时,采用拟牛顿法进行Wiener模型参数辨识,实现了高效的非线性均衡器优化.实验结果验证了该算法在非线性与线性失真补偿方面的优越性能,特别适用于高阶调制信号的传输.综上所述,DR-NEA算法有效解决了卫星通信中非线性失真与多径衰落的联合干扰问题,具有重要的理论意义和广泛的实际应用前景,特别是在高速率、高阶调制的卫星通信场景中,能够显著提升系统的传输性能.展开更多
多发射机间的同步误差是制约单频网(Single Frequency Network,SFN)信号覆盖质量的关键因素。围绕相位编码技术的特性,分析SFN系统对同步误差的敏感机制,阐述相位编码在多径环境下相较于传统方法的抗干扰优势。通过建立多分量叠加的相...多发射机间的同步误差是制约单频网(Single Frequency Network,SFN)信号覆盖质量的关键因素。围绕相位编码技术的特性,分析SFN系统对同步误差的敏感机制,阐述相位编码在多径环境下相较于传统方法的抗干扰优势。通过建立多分量叠加的相位扰动模型,提出基于双环控制结构的同步误差联合估计方法,设计一种融合变步长机制的自适应均衡补偿算法,验证了相位信息在误差传播抑制中的核心作用。展开更多
当今科技飞速发展,隐私保护成为一个重要议题.为了确保数据的安全性,通常选择将数据加密后存储在云服务器上,然而这样云服务器无法对加密后的数据进行计算、统计等有效处理,从而使得很多应用场景受限.为了解决这个问题,提出一种基于环...当今科技飞速发展,隐私保护成为一个重要议题.为了确保数据的安全性,通常选择将数据加密后存储在云服务器上,然而这样云服务器无法对加密后的数据进行计算、统计等有效处理,从而使得很多应用场景受限.为了解决这个问题,提出一种基于环上容错学习(ring learning with error,R-LWE)问题的PKE-MET(public-key encryption with a multiple-ciphertext equality test)方案,并给出了正确性和安全性分析.该方案允许云服务器同时对多个密文执行相等性测试,还能够抵抗量子计算攻击.基于Palisade库对方案进行了实现,从理论与实现的角度与其他方案进行了比较分析.相较于其他方案,该方案具有高效、运行时间短的优点.展开更多
基金Supported by the National High Technology Research and Development Program of China(863 Program,2015AA016306)the National Natural Science Foundation of China(61662010,61231015,61471271)+1 种基金Science and Technology Plan Projects of Shenzhen(ZDSYS2014050916575763)Science and Technology Foundation of Guizhou Province(LKS[2011]1)
文摘This paper proposes an unequal error protection（UEP）coding method to improve the transmission performance of three-dimensional（3D）audio based on expanding window fountain（EWF）.Different from other transmissions with equal error protection（EEP）when transmitting the 3D audio objects.An approach of extracting the important audio object is presented,and more protection is given to more important audio object and comparatively less protection is given to the normal audio objects.Objective and subjective experiments have shown that the proposed UEP method achieves better performance than equal error protection method,while the bits error rates（BER）of the important audio object can decrease from 10^（–3） to 10^（–4）,and the subjective quality of UEP is better than that of EEP by 14%.
文摘The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply Thetooth surface equation of EBCBG manufactured by end milling cutter with involute profile is de-rived. The tooth form error is analyzed on the basis of spherical involute
基金Supported by the National Natural Science Foundation of China(No.61471119)
文摘This paper evaluates the effect of decision feedback equalizer( DFE) error propagation for400 Gb/s Ethernet( 400 GbE) electrical link in order to propose some effective methods to improve bit error rate( BER). First,an analytical model for DFE burst error length distribution is proposed and simulated based on a NRZ electrical link in which a 5-tap DFE combined with a multiple-tap feed forward equalizer( FFE) is included. Then,a detailed derivation for BER considering DFE error propagation is given based on the distribution of burst error run length and the BER performance with and without forward error correction( FEC) is simulated too. After that,this paper investigates several MUX-based FEC interleaving methods including their complexity and latency in order to improve BER further. At last,three FEC interleaving schemes are compared not only in interleaving gain,but also in hardware complexities and latencies. Simulation results show that pre-interleave bit muxing can obtain good tradeoff between BER and complexity for 400 Gb E electrical link.
文摘The achievable bit error rate of a linear equalizer is crucially determined by the choice of a decision delay parameter. This brief paper presents a simple method for the efficient determination of the optimal decision delay parameter that results in the best bit error rate performance for a linear equalizer. Keywords Linear equalizer - decision delay - bit error rate Eng Siong Chng received his university education at the University of Edinburgh, Edinburgh, Scotland (BEng 1991, PhD 1995). After his PhD, he spent 6 months in Japan, working as a researcher for Riken. After working in industry in Singapore for 7 years, he joined the School of Computer Engineering, Nanyang Technological University in 2003. His research interests are in digital signal processing for communication applications, speech and handwriting recognition and noise reduction.Sheng Chen obtained a BEng degree in control engineering from the East China Petroleum Institute, Dongying, China, in 1982, and a PhD degree in control engineering from the City University at London in 1986. He joined the School of Electronics and Computer Science at the University of Southampton in September 1999. He previously held research and academic appointments at the Universities of Sheffield, Edinburgh and Portsmouth. Dr Chen is a Senior Member of the IEEE in the USA. His recent research works include adaptive nonlinear signal processing, modeling and identification of nonlinear systems, neural networks and machine learning, finite-precision digital controller design, evolutionary computation methods and optimization. He has published over 200 research papers. In the database of the world’s most highly cited researchers in various disciplines, compiled by the Institute for Scientific Information (ISI) of the USA, Dr Chen is on the list of highly cited researchers in the category that covers all branches of engineering subject, see www.ISIHighlyCited.com.
文摘This work proposes an improved inertia weight update method and position update method in Particle Swarm Optimization (PSO) to enhance the convergence and mean square error of channel equalizer. The search abilities of PSO are managed by the key parameter Inertia Weight (IW). A higher value leads to global search whereas a smaller value shifts the search to local which makes convergence faster. Different approaches are reported in literature to improve PSO by modifying inertia weight. This work investigates the performance of the existing PSO variants related to time varying inertia weight methods and proposes new strategies to improve the convergence and mean square error of channel equalizer. Also the position update method in PSO is modified to achieve better convergence in channel equalization. The simulation presents the enhanced performance of the proposed techniques in transversal and decision feedback models. The simulation results also analyze the superiority in linear and nonlinear channel conditions.
文摘针对正交时频空(Orthogonal Time Frequency Space, OTFS)调制系统中均衡器性能不佳及线性滤波器复杂度较高等问题,提出了一种LU(Lower-Upper)分解与迭代最小均方误差(Iterative Minimum Mean Square Error, IMMSE)均衡器结合的OTFS系统信号检测算法(LU-IMMSE)。该算法依据时延多普勒域稀疏信道矩阵的特征,采用一种低复杂度的LU分解方法,以避免MMSE均衡器求解矩阵逆的过程,在保证均衡器性能的前提下降低了均衡器复杂度。在OTFS系统中引入一种IMMSE均衡器,通过不断迭代更新发送符号均值和方差这些先验信息来逼近MMSE均衡器最优估计值。LU-IMMSE算法通过调节迭代次数可以有效降低误比特率。在比特信噪比为8 dB时,5次迭代后的LU-IMMSE均衡器误比特率相比传统的MMSE均衡器降低了约11 dB。随着迭代次数的增大,较传统IMMSE算法降低了计算复杂度。在最大时延系数为4、符号数为16的情况下,与直接求逆相比,所提出的低复杂度LU分解方法降低了约91.72%的矩阵求逆计算复杂度。
文摘信道仿真器中不同通道之间的幅相不一致会使系统性能恶化,通常的解决方法是在接收信道中加入校准均衡器,以校正信号传输路径中的幅度和相位失真。为了降低通道间的幅相误差、提高信道均衡效果,文中设计了一种正则化交替频域最小二乘优化算法(Regularized Alternating Frequency Domain Least Squares Optimization,RA-ALO)。该算法采用正则化来确保矩阵求逆时解的正确性,并使用交替最小二乘法(Alternating Least Squares,ALS)寻找最优解来增强均衡器性能。仿真结果表明,在信道均衡方面,与正则化算法和求伪逆算法相比,该算法具有更低的幅相误差、更优的校准性能。
文摘由于卫星通信系统中高功率放大器的非线性失真与多径信道的线性衰落效应相互耦合会引发传输性能恶化问题,而传统的盲均衡算法(如恒模算法)虽在应对多径引起的线性符号间干扰时具有一定效果,但无法有效补偿高阶调制信号中的非线性失真,尤其是在没有训练序列的盲均衡场景下,传统方法难以提供足够的监督信息.为了克服这一挑战,本文提出一种基于判决重构的非线性卫星信道盲均衡算法(blind Equalization Algorithm for Nonlinear satellite channels based on Decision-Reconstruction,DR-NEA),DR-NEA采用判决-插值-重构模式生成参考信号,从而实现无监督条件下的非线性与线性失真联合补偿.首先,算法通过恒模算法对接收到的信号进行线性均衡,消除多径效应引起的线性失真.随后,通过判决、插值和重构生成参考信号,该参考信号为非线性均衡器参数辨识提供监督信息.最后,DR-NEA使用拟牛顿法在最小均方误差准则下对Wiener型均衡器的参数进行辨识,进而实现对信道中的线性与非线性失真联合补偿.仿真结果表明,在高阶调制模式(32APSK、32QAM、64QAM)下,DR-NEA相较于传统线性均衡算法,显著提升了性能,在误码率为1×10-3时,较传统线性均衡算法性能增益超4 dB,体现了该算法在高阶调制下较强的非线性补偿能力.此外,当判决误码率低于9.44%时,DR-NEA依旧保持稳定且输出性能几乎不受影响,进一步验证了本文算法的鲁棒性.DR-NEA通过创新性地引入基于判决重构的参考信号生成方法,解决了传统盲均衡算法无法提供足够监督信息的问题.同时,采用拟牛顿法进行Wiener模型参数辨识,实现了高效的非线性均衡器优化.实验结果验证了该算法在非线性与线性失真补偿方面的优越性能,特别适用于高阶调制信号的传输.综上所述,DR-NEA算法有效解决了卫星通信中非线性失真与多径衰落的联合干扰问题,具有重要的理论意义和广泛的实际应用前景,特别是在高速率、高阶调制的卫星通信场景中,能够显著提升系统的传输性能.
文摘多发射机间的同步误差是制约单频网(Single Frequency Network,SFN)信号覆盖质量的关键因素。围绕相位编码技术的特性,分析SFN系统对同步误差的敏感机制,阐述相位编码在多径环境下相较于传统方法的抗干扰优势。通过建立多分量叠加的相位扰动模型,提出基于双环控制结构的同步误差联合估计方法,设计一种融合变步长机制的自适应均衡补偿算法,验证了相位信息在误差传播抑制中的核心作用。
文摘当今科技飞速发展,隐私保护成为一个重要议题.为了确保数据的安全性,通常选择将数据加密后存储在云服务器上,然而这样云服务器无法对加密后的数据进行计算、统计等有效处理,从而使得很多应用场景受限.为了解决这个问题,提出一种基于环上容错学习(ring learning with error,R-LWE)问题的PKE-MET(public-key encryption with a multiple-ciphertext equality test)方案,并给出了正确性和安全性分析.该方案允许云服务器同时对多个密文执行相等性测试,还能够抵抗量子计算攻击.基于Palisade库对方案进行了实现,从理论与实现的角度与其他方案进行了比较分析.相较于其他方案,该方案具有高效、运行时间短的优点.
