A high-speed realization of the delayed dual sign LMS algorithm

Abstract Vibration predictions for rotating machinery with high-speed flexible rotors must account for the methods and limitations of the balance test process which determine the residual rotor unbalance. Vibration predictions based on finite element analysis (FEA) methods are highly dependent upon the assumed rotor unbalance amplitude and phase. The actual residual unbalance distribution depends upon the measured influence coefficients and the least-mean-square (LMS) algorithm used to calculate balance correction weights. Repeatability of the vibration measurements is a key factor in successful balancing. The vibration predictions described in this paper use estimates of final residual unbalance obtained by simulating the balance test process. The simulation uses FEA based influence coefficients, a test based measurement uncertainty (repeatability) model, and LMS balance weight calculations including the specified vibration target levels. The simulations can be used to predict the limit of balance performance of the machinery and to evaluate design options for impact on residual unbalance levels.

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MATLAB Simulation of IEEE802.11p Technology on High User’s Mobility

10.21203/rs.3.rs-540883/v1 ◽

2021 ◽

Author(s):

abderrahim mountaciri

Keyword(s):

Phase Shift ◽

Doppler Effect ◽

Orthogonal Frequency Division Multiplexing ◽

High Speed ◽

Physical Layer ◽

Lms Algorithm ◽

Ieee 802.11P ◽

Vehicular Communication ◽

Matlab Simulation ◽

Vehicle To Vehicle

Abstract In this article proposed IEEE 802.11p Physical layer (PHY). A MATLAB simulation is performed to analyze the baseband processing of the transceiver. Orthogonal Frequency Division Multiplexing (OFDM) is applied in this project according to the IEEE 802.11p standard, which allows data transmission rates from 3 to 27 Mbps. Separate modulation schemes, bit phase shift modulation (BPSK), quadrate phase shift modulation (QPSK), and quadrature amplitude modulation (QAM), are used for different data rates. These schemes are combined with time interleaving and a convolutional error correction code. A guard interval is inserted at the start of the transmitted symbol to reduce the effect of intersymbol interference (ISI). This article studies the PHY physical layer of the IEEE 802.11p vehicular communication standard. An IEEE.802.11p PHY model, with many associated phenomena, is implemented in the V2V vehicle-to- vehicle, and the vehicle-to-vehicle ad hoc network (VANET) provides convenient coordination between moving vehicles. A moving vehicle could move at a very high speed, producing a Doppler effect that damages OFDM symbols and also causes inter-carrier interference (ICI). This article has discussed VANET technology versus 802.11a technology, as they have many differences when it comes to user mobility. The Doppler effect resulting from the mobility of the user with a high speed of 25 to 400 km / h has been studied as the main parameter, the estimation of the channel based on the lms algorithm has been proposed in order to improve the performance of the physical physical chain

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Hybrid MVDR-LMS beamforming for Massive MIMO

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v16.i2.pp715-723 ◽

2019 ◽

Vol 16 (2) ◽

pp. 715

Author(s):

Yasmine M. Tabra ◽

Bayan Sabbar

Keyword(s):

Massive Mimo ◽

High Speed ◽

Lms Algorithm ◽

Mean Square ◽

Least Mean Square ◽

Training Time ◽

Multiple Users ◽

Multiple Beams ◽

Time Required ◽

Beamforming Algorithm

<p>With the high speed of communication in LTE-5G, fast beamforming techniques need to be adopted. The training time required to form and steer the main lobes toward 5G multiple users must be short. Least-Mean-Square (LMS) training time is not suitable to work with in LTE-5G, but it has a good performance in forming multiple beams to large number of users and producing nulls in the interference direction. In this paper, an optimized hybrid MVDR-LMS beamforming algorithm is proposed to reduce the time required to estimate the antenna’s weights. This optimization is made by the benefit of previously set weights calculated using MVDR algorithms. The performance of the proposed hybrid MVDR-LMS algorithm tested using MATLAB 2016a.</p>

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High-Speed VLSI Implementation of an Improved Parallel Delayed LMS Algorithm

Mobile Networks and Applications ◽

10.1007/s11036-021-01877-4 ◽

2022 ◽

Author(s):

Ming Liu ◽

Mingxiang Guan ◽

Zhou Wu ◽

Chongwu Sun ◽

Weifeng Zhang ◽

...

Keyword(s):

High Speed ◽

Vlsi Implementation ◽

Lms Algorithm

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Active Magnetic Bearings for High Speed Spindle Design With Nonlinear Time-Frequency Control

Volume 4B: Dynamics, Vibration, and Control ◽

10.1115/imece2015-50994 ◽

2015 ◽

Cited By ~ 1

Author(s):

Mengke Liu ◽

C. Steve Suh

Keyword(s):

High Speed ◽

Frequency Control ◽

Air Gap ◽

Magnetic Bearings ◽

Lms Algorithm ◽

Significant Implication ◽

Active Magnetic Bearings ◽

Gyroscopic Effect ◽

Electromagnetic Actuators ◽

Time Frequency

A novel concept applicable to the control of spindles at high speed is developed by using active magnetic bearings (AMBs) that are non-contact and of low vibration. Though former studies are abundant and demonstrating promising potentials, however, two major issues hamper the broader application of AMBs. The first is the disregard for the gyroscopic effect and geometry coupling that influence the magnitude as well as distribution of the electromagnetic force in AMBs. Not considering the two has a significant implication for the proper control of AMBs. This paper considers the gyroscopic effect and explores the geometry coupling of the electromagnetic actuators to the formulation of a comprehensive nonlinear AMB-rotor model. The model provides the basis for the creation of a novel time-frequency control algorithm whose derivation requires no linearization or mathematical simplification of any kind, thus allowing the model system to retain its true fundamental characteristics. Unlike proportional-integral-derivative (PID) controllers that are dominant in most if not all AMB configurations, the controller developed for the research is inspired by the wavelet-based nonlinear time-frequency control methodology that incorporates the basic notions of online system identification and adaptive control. Due to the fact that dynamic instability is characterized by time-varying frequency and non-stationary spectrum, the control of AMBs needs be executed in the time and frequency-domain concurrently to ensure stability and performance at high speed. Wavelet filter banks and filtered-x least-mean-square (LMS) algorithm are two of the major salient physical features of the controller design, with the former providing concurrent temporal and spectral resolutions needed for identifying the nonlinear state of motion and the latter ensuring the dynamic stability of the AMB-rotor system at extremely high speed. It is shown that the vibration of the rotor is unconditionally controlled by maintaining a mandatory 0.55 mm air gap at 187,500 rpm subject to a tight spatial constraint (tolerance) of the order of 0.1375mm, which is the 25% of the air gap.

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