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Property of the constant modulus algorithm to Capture the Weak Signal

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The Journal of China Universities of Posts and Telecommunications 2003年第1期10卷 9-14页

作者： LINing GUOYan GUOLi InsituteofSciences PLAUST.Nanjing210007P.R.China SchoolofInformationEngineering BeijingUniversityofPostsandTelecommuncationsBeijing100876P.R.China

The constant modulus algorithm (CMA) enjoys widespread popularity as methodsfor blind beamform-ing and equalization of communication signals, CMA is straightforward toimplement, robust, and computationally of moderate complexity. Furthermore, it is insensitive toarray imperfection. In an environment containing multiple constant modulus signals, the signalextracted by CMA depends on the relative power of the incident signals. According previous works,the CMA is prone to capture the strongest constant modulus (CM) signal at the output of the *** this paper, we show that the weak CM signal could be recovered by CMA_(1-2) and CMA_(2-1) whensetting special step-size. Simulation examples confirm our remarks.

关键词： constant modulus algorithm step-size singular value decomposition

ADAPTIVE STEP-SIZE constant modulus algorithm FOR BLIND MULTIUSER DETECTION IN DS-CDMA SYSTEMS

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Journal of Electronics(China) 2004年第1期21卷 10-15页

作者： SunLiping HuGuangrui Dept.ofElectronicEng. ShanghaiJiaotongUniv.Shanghai200030

Blind Adaptive Step-size constant modulus algorithm (AS-CMA) for multiuser detection in DS-CDMA systems is presented. It combines the CMA and the concept of variable step-size, uses a second LMS algorithm for the step size. It adjusts the step-size according to the minimum output-energy principle within a specified range, thus overcomes the problems of bad effect of fixed step-size LMS algorithm. Compared with Adaptive Step-size LMS (AS-LMS) algoritilrn, through simulations, this algorithm can adapt the changes of the environment, suppress multiple access interference in the dynamic environment and the stability of Signal to Interference Ratio (SIR) is superior to that of AS-LMS.

关键词： CDMA constant modulus algorithm Blind interference suppression

Rayleigh Distribution Based Variable Step-Size constant modulus Blind Equalization algorithm

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Rayleigh Distribution Based Variable Step-Size Constant Modu...

New multitarget constant modulus array for CDMA systems

第一届国际测量仪器与测试自动化学术会议

作者： Han Yingge Guo Yecai (Anhui university of science and technology Huainan 232001 China)

＜正＞Aiming at the slow convergence rates of constant modulus algorithm（CMA） and Residual Error based Variable step-size CMA （REVCMA）, a novel Rayleigh Distribution based on Variable step-size CMA （RDVCMA） is proposed. In this proposed algorithm, the Rayleigh distribution function, which has two parameters and whose independent variable is an error function, is used as variable step-size. The convergence rates of the proposed RDVCMA can be improved by regulating its two parameters. We analyze the influence of the two parameters on the convergence rates and give the regulation principle of the two parameters. Simulation tests with telephone channel using 4QAM and 4PSK are carried out, respectively. The simulation results have indicated that the convergence rates of the proposed RDVCMA are faster than those of the CMA and the REVCMA under condition of the same steady state error. Accordingly, Rayleigh Distribution based Variable step-size CMA （RDVCMA） has better the performance of real time information retrieval and practicability.

关键词： constant modulus algorithm convergence rates variable step-size rayleigh distribution telephone channel.

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Journal of Systems Engineering and Electronics 2006年第2期17卷 455-457页

作者： Zhang Jidong Zheng Baoyu Jiangsu Telecom Corporation Limited Nanjing 210037 P. R. China Nanjing Univ. of Posts and Telecommunications Nanjing 210003 P. R. China

A new mulfitarget constant modulus array is proposed for CDMA systems based on least squares constant modulus algorithm. The new algorithm is called pre-despreading decision directed least squares constant modulus algorithm （D-DDLSCMA）. In the new algorithm, the pre-despreading is first applied for multitarget arrays to remove some multiple access signals, then the despreaded signal is processed by the algorithm which united the constant modulus algorithm and decision directed method. Simulation results illustrate the good performance for the proposed algorithm.

关键词： constant modulus algorithm adaptive array multiuser detection code division multiple.

A novel constant modulus array for multiuser detection

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第1期6卷 38-42页

作者：张继东郑宝玉傅洪亮 Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200030 China Bureau of Telecom Transmission Jiangsu Nanjing 210003 China Institute of Signal and Information Processing Nanjing University of Posts and Telecommunications Nanjing 210003 China Department of Communication Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

This paper proposes a new multitarget constant modulus array structure for code division multiple access (CDMA) systems. The new algorithm for the structure is called pre-despreading and wavelet denoising constant modulus algorithm (D-WD-CMA). In the new algorithm, the pre-despreading is applied to multitarget arrays to remove some multiple access inter- ferences. After that the received signal is subjected to wavelet de-noising to reduce some noise, and used in CMA adaptive iteration for signal separation. Simulation results showed that the proposed algorithm performed better than the traditional CMA algorithm.

关键词： constant modulus algorithm Adaptive array Wavelet de-noising Multiuser detection CDMA

Fractionally Nyquist Sample Spaced ARMA Blind Equalizer for Direct Signal Recovery in Passive Bistatic Radar

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Chinese Journal of Electronics 2017年第3期26卷 658-666页

作者： WANG Feng SHEN Wei JIANG Defu WEI Shuang Array and Information Processing Laboratory College of Computer and Information Hohai University Nanjing Research Institute of Electronics Technology

This paper proposes a modified signal processing structure based on the fractionally Nyquist sample spaced structure for passive bistatic *** recover the direct signal from the multipath clutter,an equalizer of the Auto regressive moving average(ARMA)type is proposed based on the fractionally Nyquist sample spaced constant modulus *** with the conventional Nyquist sample spaced equalizer,the equalizer of the fractionally Nyquist sample spaced ARMA structure is more effective in dealing with deep fading multipath channels with zeros near the unit *** simulations and real data tests indicate that the proposed approach outperforms the conventional processing structure in terms of both clutter residual and mean square error.

关键词： Passive bistatic radar constant modulus algorithm Direct signal recovery Multipath clutter cancellation Fractionally spaced equalizer

Blind Equalization Using Coordinate Mapping for 4-PAM and 16-QAM Signals

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Chinese Journal of Electronics 2014年第1期23卷 124-128页

作者： RAO Wei Nanchang Institute of Technology

It is well known that the famous constant modulus algorithm(CMA) presents a large steady-state Mean square error(MSE) for nonconstant modulus signals. In this paper a coordinate mapping approach for a4-PAM nonconstant modulus signal is described which can change the signal to an Offset QPSK(OQPSK) constant modulus signal. And a new algorithm based on this approach is proposed which is also suitable for a 16-QAM signal. For the 4-PAM and 16-QAM nonconstant modulus signals the proposed algorithm can achieve a zero steadystate MSE in a noiseless environment but CMA *** analysis and simulations results demonstrate the high performance of the proposed algorithm.

关键词： Blind equalization constant modulus algorithm Coordinate mapping

A Novel constant modulus Array for Multiuser Detection

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A Novel Constant Modulus Array for Multiuser Detection

Semi-blind Adaptive Beamforming for High-throughput Quadrature Amplitude Modulation Systems

第七届国际信号处理会议

作者： ZHANG Ji-dong 1 ZHENG Bao-yu 2 Fu Hong-liang2 (1: ShangHai JiaoTong University Shanghai China 200030 2:NanJing University of Posts and Telecommunications NanJing China 21000

A novel multitarget constant modulus array structure is proposed for CDMA systems in this paper. The new algorithm for the structure is called pre- despreading and wavelet denoising constant modulu

关键词： constant modulus algorithm Wavelet denoising Multiuser detection Communication signal processing

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International Journal of Automation and computing 2010年第4期7卷 565-570页

作者： Lajos Hanzo School of Electronics and Computer Science University of Southampton

A semi-blind adaptive beamforming scheme is proposed for wireless systems that employ high-throughput quadrature amplitude modulation signalling. A minimum number of training symbols, equal to the number of receiver antenna arrayts elements, are first utilised to provide a rough initial least squares estimate of the beamformer＇s weight vector. A concurrent constant modulus algorithm and soft decision-directed scheme is then applied to adapt the beamformer. This semi-blind adaptive beamforming scheme is capable of converging fast to the minimum mean-square-error beamforming solution, as demonstrated in our simulation study.

关键词： Beamforming minimum mean square error quadrature amplitude modulation semi-blind adaptive algorithm constant modulus algorithm soft decision-directed scheme.