Papers by Keyword: Variable Step Size

Paper TitlePage

Authors: Dhananjay Ghangale, Dhanesh Manik
Abstract: — Active noise control is used to reduce low frequency noises. A hybrid ANC structure combines feedforward and feedback structure to generate an anti-noise wave, which results in high performance in control of unwanted noise. In this paper, a hybrid structure for active noise control (ANC) is developed. The hybrid structure utilises a variable step size LMS algorithm for faster convergence. This structure also incorporates variable step size (VSS) online secondary path modelling, the white noise injection is stopped at the optimum point when the modelling accuracy is sufficient. Comparative simulation results shown in this paper indicate the effectiveness of the proposed approach in reducing acoustic noises.
2455
Authors: Wei Ju Cai
Abstract: The paper proposed a modified LMS algorithm of variable step size based on a brief analysis of traditional LMS,variable step size LMS algorithm and its improved algorithm.The novel algorithm based on nonlinear functional relationship between the step-size and the error ,increases adaptively at the beginning of the algorithm or when the channel is varying with time ,and it would be smaller during the steady state.So the algorithm has the excellences of faster constringency,little steady error ,tracking the change of the system and avoiding the effects of the noise. The theoretical analysis and computer simulation prove that the algorithm is better than traditional LMS algorithm.
2193
Authors: Fu Qing Tian, Rong Luo
Abstract: In the paper, a new variable step size LMS algorithm based on modified hyperbolic tangent is presented. In the algorithm, the step size is adjusted by the estimation of the autocorrelation between and .The algorithm introduces the compensation monomial to improve the convergence and the parameters to improve the shape and bottom characteristic of hyperbolic tangent. Therefore, the algorithm has faster convergence, better performance of noise suppression,lower steady state error and misadjustment. The theoretical analysis and simulation results all show that the overall performance of the new algorithm exceeds greatly some existent others under low SNR condition.
1426
Authors: Xiang Zhao, Jin Yong Sun, Han Hong Tan
Abstract: A variable step size Constant Modulus Algorithm (CMA) based on the gamma distribution is implemented as solutions to optimize the problem of blind equalization. The factor of step size in blind equalization algorithm is varied with gamma variable, in terms of the characteristics of which, the algorithm can search for the globe optimal equalizer weight vector. Simulation results indicate that the convergence rate and the steady Mean Square Errors (MSE) performances of the algorithm proposed are much better than conventional CMA and modified CMA blind equalization algorithms.
961
Authors: Ying Xiao, Zhen Xing Li
Abstract: Step-size is one of the important parameters which influence the performance of blind equalization, a variable step-size method control by attenuation function according to instantaneous gradient and iterative times is proposed in this paper. Initially, set larger step-size to obtain faster convergence, with iterative times increasing, step-size would decrease control by attenuation function for instantaneous gradient reducing. Step-size changes according to this method consistent with the demand variable step-size adaptive algorithm that can obtain combination of convergence rate and convergence precision to improve the performance of blind equalization. Simulations show that this method performs better than conventional blind equalization with constant step-size.
1792
Authors: Fang Fang Han, Zi Hao Lin
Abstract: To further improve the performance of adaptive equalization in HF channel, a new variable step size algorithm is proposed based on the iterative gradient. The step size is set to a vector according to the weights of the equalizer, and it can vary with the iterative gradient during the equalization process. The algorithm overcomes the traditional variable step size with the constant scale for all the weights of the equalizer, thus it can obtain faster convergence rate and lower steady state error in HF channel. In the complex channel condition, the algorithm proposed in this paper can avoid the local minimum point of the objective function to obtain the global convergence performance. Simulation result shows the effectiveness in the Watterson channel model.
3702
Authors: Rui Mei Lian
Abstract: An amended LMS Newton algorithm is proposed which create the nonlinear functional relation of the step factor μ and the error signal e (n). And the next we discuss the factors in the amended algorithm and the performance in the different IP environment. The algorithm is simple and easy to be implemented, Theoretical analysis and computer simulation show that the properties of the algorithm such as convergence speed, and steady state error ate better than those of SVSLMS algorithm.
458
Authors: Shi Ping Zhang, Guo Qing Shen, Lian Suo An
Abstract: Acoustic pyrometry is a comparatively advanced method of temperature measurement developed in recent years, which possesses the essential characteristics of traditional temperature measurement approach. Considering the interferences, like strong background noise, reverberation and so on, in boiler furnace, the LMS (least mean square) adaptive filter algorithm should be improved to meet certain environment above. In order to make the LMS algorithm have the characteristic of fast convergence and small steady state error, an improved, power-normalized and variable step-size discrete cosine transform LMS algorithm is proposed, which combines the power-normalized discrete cosine transform LMS algorithm with the variable step size LMS algorithm that uses the sliding forgetting-weighted window. The time delay estimation simulation in the strong-noise environment verifies the improved DCT-MVSS LMS algorithm can achieve good performance.
2025
Authors: Shi Ping Zhang, Guo Qing Shen, Lian Suo An
Abstract: Time delay estimation plays an important role in accuracy of leakage location in industrial boiler furnace. Considering about interference, like strong background noise, reverberation and so on, in boiler furnace, the LMS (least mean square) adaptive filter algorithm should be improved to meet certain environment above .In order to makes the LMS algorithm have the characteristic of fast convergence and small steady state error, an improved, power-normalized and variable step-size discrete cosine transform LMS algorithm is proposed, which combines the power-normalized discrete cosine transform LMS algorithm with the variable step size LMS algorithm that uses sliding forgetting-weighted window . The time delay estimation simulation in the strong-noise environment verifies the improved DCT-MVSS LMS algorithm can achieve good performance.
699
Authors: Shou Zhong Zhang
Abstract: Neural network is acted as noise canceller to implement noise cancel under the condition of interference noise has nonlinear correlation to reference noise. If interference noise has nonlinear correlation to reference noise, the transversal filter has weak effect to cancel the noise in the signal. Neural network has nonlinear characteristic transfer and can solve this problem, and a new variable step size algorithm is proposed to further improve the performance. Computer simulation results show that neural network noise canceller has better signal to noise gain for nonlinear noise.
709
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