• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.67-73
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• 2013

This paper relates with the performance of VSCA 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 VSCA, it is possible to the increase the equalization performance by adding the concept of distance adjusted approach for constellation matching. We compare the performance of VSCA and SCA algorithm by computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used for perfomance comparison. It was confirmed that, the VSCA algorithm has better than the SCA in every performance index by computer simulation.

• 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.12 no.4
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• pp.7-13
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• 2012

The performance of blind equalization algorithm ISCA was compared with MSCA that is used for the minimization of the inter symbol interference which occurs in the time dispersive communication channel for digital transmission. Because of the non-linearities of a magnitude and phase transfer characteristics of a communication channel, the transmitting signal will be received that band limited and time dispersived. Therefore the distortion was compensated by using the self adaptive equalizer at the receiving side, then passing through the detector for the decision of "1" or "0". At this time the Constellation Dependent Constant is played an important role in the adaptive equalizer used on the receiver. In order to calculation of this constant, the ISCA and MSCA was used the second order statistics. The ISCA and MSCA which are possible to compensation of mensioned transfer function simulataneously, are improved the performance of original SCA algorithm and then was compared the performance by computer simulation. For this, the recovered constellation, residual isi and MSE was used, and a result of performance comparison, the ISCA algorithm has better than the MSCA in every performance index. But on the steady state of equalizer, the variation of performance due to the CME terms in the MSCA equalization algorithm was less than the ISCA, so MSCA has better stability.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.159-165
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• 2012

This paper deals with the performance comparison of adaptive equalization algorithm, MMA and SCA, that is used for the minimization of the distortion and noise effect in the communication channel.. The transmitting signal will be distorted and received due to the nonlinearties of magnitude and phase transfer characteristics of communication channel, the compensation of it by using the self adaptive equalizer. The constant modulus has important metric in the self adaptive equalizer, the MMA uses the 2nd and 4th high order statistics of transmitting signal, the SCA uses the 2nd order statistics of transmitting signal only in order to the calculation of it. We compared to the compensation performance of the MMA and SCA by the computer simulation that are possible to the compensation of the two kinds of transfer characteristics at same times by the relatively simple arithmatic operation. We used to the recovered constellation, residual isi and MSE, SER that are the essential index for the comparison of the adaptive equalizer. The result of performance comparison of algorithms, the MMA which uses the high order statistics of transmitting signal has good performance in the MSE and SER compared to the SCA which is using the low order statistics. But in the recovered costellation and residual isi, the SCA has a good than the MMA.