检索结果-内蒙古大学图书馆

Experimental demonstration of modified constant modulus algorithm with polarization demultiplexing in Stokes space in optical coherent receiver

引用

OPTICS COMMUNICATIONS 2025年 583卷

作者： Huang, Bohang Dong, Xiangyong Shi, Fengjie Yu, Zhenming Xu, Kun Beijing Univ Posts & Telecommun State Key Lab Informat Photon & Opt Commun Beijing 100876 Peoples R China

constant modulus algorithm (CMA) is widely applied for polarization demultiplexing in coherent optical communication system. However, the singular value problem always plagues CMA. Modified CMA based on polarization demultiplexing in Stokes space (SS-PDM) was proposed to avoid the singular value problem in simulation. Here we firstly experimentally demonstrate the modified CMA based on SS-PDM in optical coherent receivers. We conduct experiment of 40-Gbit/s polarization multiplexing (PDM) QPSK to verify this method. The experimental results show that the singularity problem of CMA disappears for Polarization-dependent loss (PDL) of 2.7 dB and 4.8 dB by using the modified CMA and the convergence speed of the modified CMA increases significantly compared with that of conventional CMA.

关键词： Polarization demultiplexing Coherent detection constant modulus algorithm Stokes space Polarization-dependent loss

来源：评论

学校读者我要写书评

暂无评论

constant modulus algorithm for blind equalization of multipath transmitted video signals in cable networks

引用

SIGNAL PROCESSING-IMAGE COMMUNICATION 2001年第5期16卷 413-420页

作者： Lei, ZC Franzen, O Brakensiek, J Schröder, H Univ Dortmund Chair Commun Tech D-44227 Dortmund Germany

In this paper we present an approach to equalize multipath transmitted video signals without any reference signal. This approach takes advantage of the constant envelope feature of the color burst signal, which is transmitted in the blanking interval of each TV line and can be considered as an angle-modulated signal. The constant modulus algorithm (CMA) after Treichler is modified for our purpose. Special attention is given to the equalization of video signals in PAL systems. By making full use of the genuine phase feature of the color burst signal in PAL systems, the Hilbert transform needed by CMA can be saved for equalizing PAL system video signals. In addition to equalize analog TV signal, this paper can also lead to a joint echo cancellation of analog and digital TV signals transmitted in cable network. (C) 2001 Elsevier Science B.V. All rights reserved.

关键词： constant modulus algorithm CMA blind equalisation video equalising color burst cable network equalisation echo cancellation

来源：评论

学校读者我要写书评

暂无评论

constant modulus algorithm aided soft decision directed scheme for blind space-time equalisation of SIMO channels

引用

SIGNAL PROCESSING 2007年第11期87卷 2587-2599页

作者： Chen, S. Wolfgang, A. Hanzo, L. Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

This paper investigates a blind space-time equaliser (STE) designed for single-input multiple-output (SIMO) systems that employ high-throughput quadrature amplitude modulation schemes. A constant modulus algorithm (CMA) aided soft decision-directed (SDD) scheme, originally derived for low-complexity blind equalisation of single-input single-output channels, is extended to the SIMO scenario. Simulations are conducted to compare the performance of this blind adaptive scheme with another low-complexity blind STE referred to as the CMA aided decision directed (DD) scheme. The results obtained demonstrate that for SIMO systems the CMA aided SDD scheme exhibits advantages over the CMA aided DD arragement, in terms of its faster convergence speed and lower computational complexity.(c) 2007 Elsevier B.V. All rights reserved.

关键词： single-input multiple-output space-time equalisation quadrature amplitude modulation constant modulus algorithm decision-directed adaptation

来源：评论

学校读者我要写书评

暂无评论

Widely linear UKF constant modulus algorithm for blind adaptive beamforming

引用

Journal of Systems Engineering and Electronics 2017年第3期28卷 413-423页

作者： Huaming Qian Ke Liu Long Li Linchen Qian Junda Ma College of Automation Harbin Engineering University Advanced Signal Processing Lab College of EngineeringTemple University Information Communication Branch State Grid Heilongjiang Electric Power Company Limited School of Computing Beihang University

Based on a uniform linear array, a new widely linear unscented Kalman filter-based constant modulus algorithm (WL-UKF-CMA) for blind adaptive beamforming is proposed. The new algorithm is designed according to the constant modulus criterion and takes full advantage of the noncircular property of the signal of interest (SOI), significantly increasing the output signal-to interference-plus-noise ratio (SINR), enhancing the convergence speed and decreasing the steady-state misadjustment. Since it requires no known training data, the proposed algorithm saves a large amount of the available spectrum. Theoretical analysis and simulation results are presented to demonstrate its superiority over the conventional linear least mean square-based CMA (L-LMS-CMA), the conventional linear recursive least square-based CMA (L-RLS-CMA), WL-LMS-CMA, WL-RLS-CMA and L-UKF-CMA.

关键词： widely linear filtering blind beamforming noncircular signals constant modulus algorithm unscented Kalman filtering

来源：评论

学校读者我要写书评

暂无评论

Performance analysis of the linearly constrained constant-modulus algorithm-based multiuser detector

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2005年第2期53卷 643-653页

作者： Whitehead, JB Takawira, F Univ KwaZulu Natal Sch Elect Elect & Comp Engn ZA-4001 Durban South Africa

This paper quantifies the adaptive performance of a blind adaptive multiuser detector (MUD) based on the linearly constrained constant modulus algorithm (LCCMA) in both a stationary and nonstationary channel. A framework is developed to apply the feedback analysis method to analyzing adaptive MUD schemes. A closed-form expression for the excess mean square error (EMSE) of LCCMA blind adaptive MUD in a CDMA communications system is derived for both of the steady-state and tracking cases. The effects of additive noise and multiple access interference are considered. A transient analysis is performed that predicts the learning curve of the adaptive filter. Computer simulation is used to verify the accuracy of the analysis.

关键词： blind adaptive multiuser detection code division multiple access constant modulus algorithm excess mean square error feedback analysis steady-state analysis tracking analysis

来源：评论

学校读者我要写书评

暂无评论

Steady-state mean-square error analysis of the cross-correlation and constant modulus algorithm in a MIMO convolutive system

引用

IEE PROCEEDINGS-VISION IMAGE AND SIGNAL PROCESSING 2002年第4期149卷 196-203页

作者： Luo, Y Chambers, JA Kings Coll London Sch Phys Sci & Engn Ctr Digital Signal Proc Res London WC2R 2LS England

The cross-correlation and constant modulus algorithm (CC-CMA) has been proven to be an effective approach in the problem of joint blind equalisation and source separation in a multi-input and multi-output system. In the paper, the steady-state mean-square error performance of CC-CMA in a noise-free environment is studied, and a new expression is derived based on the energy preservation approach of Mai and Sayed (2000). Simulation studies are undertaken to support the analysis.

关键词： mean square error methods multi-input multi-output system MIMO convolutive system joint blind equalisation source separation Signal processing and detection correlation methods convolution energy preservation approach CC-CMA blind equalisers Interpolation and function approximation (numerical analysis) MIMO systems constant modulus algorithm Communication channel equalisation and identification noise-free environment Steady-state mean-square error analysis Signal processing theory cross-correlation

来源：评论

学校读者我要写书评

暂无评论

Modified constant modulus algorithm With Polarization Demultiplexing in Stokes Space in Optical Coherent Receiver

引用

JOURNAL OF LIGHTWAVE TECHNOLOGY 2013年第19期31卷 3203-3209页

作者： Yu, Zhenming Yi, Xingwen Zhang, Jing Deng, Mingliang Zhang, Hongbo Qiu, Kun Univ Elect Sci & Technol China Key Lab Opt Fiber Sensing & Commun Minist Educ Chengdu 611731 Peoples R China

We propose a modified method of constant modulus algorithm (CMA) based on polarization demultiplexing in Stokes space for polarization demultiplexing (SS-PDM) in optical coherent receivers. SS-PDM can tolerate chromatic dispersion (CD) and polarization-dependent loss (PDL), but is sensitive to PMD. On the other hand, the CMA with high-order FIR filters could compensate for polarization-mode-dispersion (PMD) effectively, but suffers from the singularity problem which results from PDL. Therefore, we use the polarization rotation matrix estimated by SS-PDM to set the initial center taps of the CMA. The singularity problem of the CMA is avoided effectively in a much wider range of PDL and its convergence speed is also improved. We demonstrate this modified CMA in a simulation of 100-Gbit/s PDM-QPSK with PDL of 1, 3, and 5 dB, respectively. PDL is emulated by attenuating one polarization tributary before polarization multiplexing and the interaction between PDL and PMD is ignored. The singularity problem disappears as expected. Because the tolerance of PDL is affected by DGD, we further investigate the PDL tolerance under different DGD. Finally, we conduct the simulation of 100-Gbit/s PDM-QPSK with PDL of 3 dB over 3000 km SSMF and 4000 km SSMF separately. The convergence speed accelerates indeed compared with that of the conventional CMA.

关键词： Coherent detection constant modulus algorithm polarization demultiplexing polarization-dependent loss polarization-mode-dispersion Stokes space

来源：评论

学校读者我要写书评

暂无评论

Anchored blind equalization using the constant modulus algorithm

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS 1997年第5期44卷 397-403页

作者： Kamel, RE BarNess, Y NEW JERSEY INST TECHNOL DEPT ELECT & COMP ENGN CTR COMMUN & SIGNAL PROCESS RES NEWARK NJ 07102 USA

Blind equalization is a technique of adapting an equalizer without the need of a training sequence, The constant modulus algorithm (CMA) is one of the first known blind equalization algorithms. The cost function of the CMA exhibits local minima, which are the primary cause of the ill-convergence of the CMA, Using the CMA with an anchored equalizer greatly improves the performance of the CMA in terms of ill-convergence. This technique is used in this paper with the linear and the decision feedback equalizers, Theory and simulation show that such an adaptive equalizer will always remove intersymbol interference (ISI) provided the main cursor's gain exceeds a certain critical value.

关键词： blind equalization constant modulus algorithm

来源：评论

学校读者我要写书评

暂无评论

Dynamically Partitioned Hierarchical constant modulus algorithm for Variable Delay Spread Channels

引用

WIRELESS PERSONAL COMMUNICATIONS 2012年第2期62卷 395-410页

作者： Woo, Tai-Kuo Natl Def Univ Dept Informat Management Taipei Taiwan

The constant modulus algorithm (CMA) adopts the constant modulus (CM) criterion to minimize the deviation of the equalizer output from a fixed value. However it has two drawbacks: (1) slow rate of convergence (2) the likelihood of getting trapped in a local minimum. The problem gets even worse when the channel delay spread varies rapidly as the filter length cannot match the delay spread. If the filter length is significantly longer than the delay spread, the convergence rate can be slow. In this paper, we improve the performance of the standard CMA by using a dynamically partitioned hierarchical structure to organize the taps of a filter. The filter length is dynamically partitioned according to the delay spread such that they are tightly matched. Preferably, the length of a sub-filter is slightly longer than the delay spread of the channel. The performance evaluation is divided into two parts. In Part I, we do simulation runs for both the cost functions and cost surfaces comparing the standard CMA, where the filter length is significantly longer than the delay spread, and the dynamically partitioned CMA, where the filter length matches the delay spread. In Part II, an analysis is provided to show that the proposed partitioned scheme can speed up the convergence rate and reduce the cost function.

关键词： Adaptive filtering CMA constant modulus algorithm Hierarchical filtering

来源：评论

学校读者我要写书评

暂无评论

Fuzzy-logic tuned constant modulus algorithm and soft decision-directed scheme for blind equalisation

引用

DIGITAL SIGNAL PROCESSING 2010年第3期20卷 846-859页

作者： Chen, S. Luk, B. L. Harris, C. J. Hanzo, L. Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England City Univ Hong Kong Dept Mfg Engn & Engn Management Hong Kong Hong Kong Peoples R China

This contribution revisits blind equalisation for high-order quadrature amplitude modulation systems using a low-complexity high-performance concurrent constant modulus algorithm (CMA) and soft decision-directed (SDD) scheme. A fuzzy-logic (FL) tuning unit is designed to adjust the step size of the CMA, and the potential benefits of using this adaptive step size approach are investigated. Simulation results obtained confirm that faster convergence can be achieved with this FL assisted CMA and SDD scheme, compared with the previous constant step-size CMA and SDD scheme. Quantitatively, the former requires several thousands fewer samples to converge to the same steady-state solution achieved by the latter. (C) 2009 Elsevier Inc. All rights reserved.

关键词： Blind equalisation Quadrature amplitude modulation constant modulus algorithm Soft decision-directed adaptation Minimum mean square error Adaptive step size Fuzzy logic

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：