• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.139-145
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• 2015

This paper compare the VSCA (Variable stepsize Square Contour Algorithm) and VSDA (Variable stepsize Square contour Decision directed Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference which occurs in the time dispersive channel for the transmission of 16-QAM signal.. In the SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSCA and VSDA, it is possible to the improving the equalization performance by varing the stepsize using the concept of distance adjusted approach for constellation matching. We compare the performance of the VSCA and VSDA algorithm by the computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used in the performace index. As a result of computer simulation, the VSCA algorithm has better than the VSDA in every performance index.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.85-91
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• 2014

This paper relates with the VSDA (Variable stepsize Square contour Decision directed Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference due to the distortion which occurs in the time dispersive channel for the transmission of 16-QAM signal.. In the conventional SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSDA, it is possible to the increasing the equalization performance by adding the concept of distance adjusted approach for constellation matching and the cost function of decision directed. We compare the performance of VSDA and SCA algorithm by the computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used in the performace index. As a result of computer simulation, the VSDA algorithm has better than the SCA in convergence speed, but it gives nearly same equalization performance in other index.