作者：
Zhao LiyeLi HongshengSoutheast Univ
Minist Educ Key Lab Micro Inertial Instrument & Adv Nav Techn Sch Instrument Sci & Engn Nanjing Jiangsu Peoples R China
Strong damping and large time constant is the common characteristics of marine gravity meter, in which they suppress vertical interference in the direction of the acceleration, but also result in distortion of the low...
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ISBN:
(纸本)9780769551227
Strong damping and large time constant is the common characteristics of marine gravity meter, in which they suppress vertical interference in the direction of the acceleration, but also result in distortion of the low-frequent gravity anomaly signals, such as amplitude attenuation and phase lag. Based on the principle of the gravimeter and the distortion of measured signals, measured distortion signals of the gravimeter can be approximately taken as the result of gravity signal convoluted with the unknown coefficients of the low-pass filter. Then, the single-channel Bussgang method based on the sato algorithm is analyzed and used to correct the gravity anomaly distortion signal. Theoretical analysis and the result of emulations show that the correction algorithm based on the blind deconvolution can effectively eliminate the amplitude attenuation and phase lag of the gravity signal distortion and improve the accuracy of the gravity anomaly.
A dynamical system can often be described in terms of partial differential equations (EDP) or ordinary differential equations (ODE) equations. Moreover, if the long-term dynamic behavior represented in a phase space c...
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A dynamical system can often be described in terms of partial differential equations (EDP) or ordinary differential equations (ODE) equations. Moreover, if the long-term dynamic behavior represented in a phase space converges in a disordered way to an attractor, this response is called chaotic. In many cases, it is considered deterministic chaos, i.e., the response follows a unique evolution, which is sensitive to initial conditions, making the behavior difficult or impossible to predict. Such phenomenon can be found in aeroelastic panels, subject to aerodynamic loads and temperature variation, which is the subject of study in this paper. This work address the dynamic analysis of a flat rectangular plate under flutter panel conditions. The system was modeled using Rayleigh-Ritz approximation and the temporal response is obtained using numerical integration by New-Mark method. The dynamic analysis of the system is performed by obtaining the Poincare plane by Henon algorithm. Furthermore, using the brute-force search, or exhaustive search, and the Poincare plane, the bifurcation diagrams were plotted for different pressure and temperature factors. In addition, the 0-1 test for chaos by time series was used to detect the occurrence of non-regular stationary responses. Finally, in the cases of chaos, the Lyapunov exponents were computed using the sato algorithm. The results showed that the current approach was able to assess the presence or not of deterministic chaos. Furthermore, the results showed how the dynamic pressure and temperature factor affect the dynamic responses.
We obtain the convergence of the Godard family [including the sato and constant modulus (CM) algorithms] and the multimodulus algorithms (MMA) in a unified way. Our analysis also works for CMA fractionally spaced equa...
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We obtain the convergence of the Godard family [including the sato and constant modulus (CM) algorithms] and the multimodulus algorithms (MMA) in a unified way. Our analysis also works for CMA fractionally spaced equalizer (FSE). Our assumptions are quite realistic: The channel input can be asymptotically stationary and ergodic, the channel impulse response is finite and can be stationary and ergodic (this models fading channels), and the equalizer length is finite. The noise is independent and identically distributed (i.i.d.). The channel input can be discrete or continuous. Our approach allows us to approximate the whole trajectory of the equalizer coefficients. This provides estimates of the rate of convergence, and the system performance (symbol error rate) can be evaluated under transience and steady state.
The modern digital high speed wireless communication system demands quick convergence rate and low steady state error. The balancing between the demands can be achieved by opting step size. Thus, it is essential to de...
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The modern digital high speed wireless communication system demands quick convergence rate and low steady state error. The balancing between the demands can be achieved by opting step size. Thus, it is essential to define new algorithms to equalize channels and mitigate noise in communications. It is renowned that time varying step size blind equalization technique can speed up the convergence rate and minimize the misadjustment. This work presents a variable step size (VSS) approach based on godard blind equalization algorithm to resolve the conflict between the convergence rate and precision of the fixed step-size godard algorithm. The results of this projected approach is compared with the existing variable step size sato algorithm for a pulse amplitude modulated (PAM) input symbol.
One of the practical problems in digital communications is inter-symbol interference (ISI), which causes a given transmitted symbol to be distorted by other transmitted *** ISI is imposed on the transmitted signal due...
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One of the practical problems in digital communications is inter-symbol interference (ISI), which causes a given transmitted symbol to be distorted by other transmitted *** ISI is imposed on the transmitted signal due to the band limiting effect of the practical channel and also due to the multi-path effects of the channel. The channel distortion may yield high error rate in symbol detection .One of the most commonly used techniques to compensate the channel distortion is linear channel equalization. More recently, there have been much interest in blind (self-recovering) channel equalization where no training sequences are available or used. In this thesis, we will discuss various equalization methods, including training based and blind methods. Of particular interest are the adaptation *** this paper, computer simulations for blind equalization case is done verifying the validity of the theory. So, Godard family algorithm, an important class of adaptive blind channel equalization is implemented. As stochastic gradient descent in nature, they have practical computer implementation, but they have slowly initial convergence. Godard algorithms simulation results confirm better performance for constant modulus algorithm, CMA.
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