• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.7
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• pp.3550-3565
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• 2019

This paper proposes a new measurement method for the effective measurement of the 99% occupied bandwidth (OBW) at monitoring stations. Although the OBW measurement of radio signal is recommended by the International Telecommunication Union Radio (ITU-R) with several methods, there still does not exist a clear measurement recommendation or standard for terrestrial DTV signal on-air environment. Modified adjacent channel power ratio (MACPR), which can be applied to 8-VSB (Vestigial Side Band) DTV (Digital Television) signal, is herein defined to verify the results of measurements obtained using the proposed measurement method. MACPR is a proper measuring parameter for determining the measuring area of a monitoring station. From measurement results obtained in real field environment, it has been found that the OBW of 8-VSB DTV signal can be effectively measured in areas where the MACPR value is over 35 dB and when the measurements are repeated more than 600 times in the same reception site. It also has been verified that measured results are within an error range of +/-0.1% compared to results directly obtained at a transmission station. It is expected that the proposed method is able to be employed in order to determine the proper location of monitoring station and provide a reliable OBW measurement procedure for 8-VSB DTV signal on-air environment.

• Journal of Broadcast Engineering
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• v.18 no.3
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• pp.435-444
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• 2013

ATSC terrestrial DTV system can support high data rates for HDTV(High Definition Television) service, but it suffers from significant performance degradation caused by multipath fading. Thus, it is necessary to analyze multipath fading effects in order to enhance the DTV reception performance. Generally, DTV channel profile can be obtained by auto-correlation between reference pseudo random signal and received DTV signal. However, in the ATSC terrestrial DTV system, the estimation performance of DTV channel profile may be decreased due to the VSB modulation features. In this paper, improved DTV channel profile measurement technique is analyzed and proposed.

• Journal of Broadcast Engineering
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• v.12 no.4
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• pp.373-376
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• 2007

Recently, research on the enhancement of the conventional VSB scheme for DTV signal transmission have been done. Not to affect on the performance of the widely spread conventional receivers and at the same time be able to receive the enhanced stream. there have been efforts to enhance the coding scheme which is backward compatible with the conventional method. The conventional schemes proposed so far is based on the idea of combining a new trellis encoder with the standard 8-VSB trellis encoder. In this paper, we Propose serial concatenated turbo TCM scheme which combines two trellis encoder with the interleaver between them. We compare the performance of the proposed scheme and the existing scheme through computer simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.10
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• pp.1737-1743
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• 2006

OCR(On channel repeater) provides the high frequency reuse efficiency for allocating frequency bands to repeaters because the frequency of input and output signals of OCRs is the same. However the oscillation probability of OCRs is high due to the same input and output frequency. In order to prevent a repeater from oscillating, we must keep the antenna isolation higher than the gain of the repeater with a some margin. In this paper we simulated the effects of the amplitude, phase and time delay of feedback signals (m the characteristics of non-regeneration OCR. Simulation results show that the highest probability of oscillation is occurred when the gain of a repeater is the same value of the isolation. From the simulation results, we know that the phase of feedback signals can be adjusted to reduce the possibility of oscillation if a non-regeneration repeater has a narrow operation bandwidth or a signal bandwidth is narrow. As the time delay increases, the probability of oscillation and the fluctuation of gain over a certain frequency band increase also. The effects of the amplitude and phase of feedback signals on S/N of 8-VSB signal for generation and non-generation repeater were tested. The measured results show that the set-top can receive 8-VSB signal when the received signal power is $17{\sim}18dB$ higher than the noise power. When the isolation is almost same as the gain of the repeater, then the set-top can not receive 8-VSB signals due to the oscillation of the repeater. And the phase of feedback signals affects S/N at the output of the repeater when the isolation is $11.75{\sim}13.75dB$ larger than the gain of the repeater. In this case the set-top can not receive 8-VSB signal of at $48^{\circ}\;and\;347^{\circ}$ of the phase of feedback signals. However the phase of feedback signals can not affect the S/N of 8-VSB signals of the generation repeater because of the demodulation and modulation process of the generation repenter. The set-top can not receive 8-VSB signals when the amplitude of feedback signals is $12.6{\sim}13.6dB$ larger than the wanted signal power at the input port of the repeater. It's because that the amplitude of feedback signals saturates the front end of the repeater.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.94
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• pp.277-285
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• 2005

In this paper, we propose the occupied bandwidth(OBW) measurement method for effectively measuring the 99 $\%$ OBW at monitoring station. In order to validate the measurement results obtained from the proposed measurement method, the modified adjacent channel power ratio(MACPR) is herein defined as the formula which was suitable for applying to the OBW measurement of 8-VSB DTV signals. It has been found that the MACPR is a good measurement parameter applicable for the proper site selection of monitoring station and the effective OBW measurement of 8-VSB DTV signals should be made for MACPR$\geq$35 dB with 600 measurement trials. The proposed measurement procedure is herein given and proven to effectively be applicable to the OBW measurement of terrestrial 8-VSB DTV signals on the air.

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.56-62
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• 2006

In this paper, we simulated terrestrial digital broadcasting system and analyzed the performance of 8-VSB signal and carried out baseband simulation of tranceiver modeling by standard parameter and passband simulation for interchannel interference. Also, an error rate equation for fading and interference of 8-VSB signal is derived. As a result, the case not to consider Rician fading, the influence of the interference did not exist if frequency interval fell off over the 20MHz. The case to consider Rician fading, the system had the degradation of the performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.116-125
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• 2003

According to the recent developments of computer, terrestrial broadcasting, satellite broadcasting and CATV technologies, Multimedia TV application combined with such technologies will emerge. Therefore, it is demanded that high-power, wide-band, and high-frequency performance. In this paper, HPA(high power amplifier) for digital TV transmission system is proposed. The analysis and evaluation on the proposed amplifier have been performed by 2-tone signal for general performance evaluation and by 8-VSB signal for comparison with real system. In result, proposed HPA satisfies requirements of high-power, wide-band, and high-frequency performance.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.63-75
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• 2010

In this paper, the equalizer techniques that is able to adopt the digital on-channel repeater for 8VSB-based DTV system has been analyzed and we propose an effective equalizer structure which can reduce the error propagation phenomenon by the feedback signal and improve the receiver performance at the same time. In order to confirm the effective cancellation of the feedback signal, the multi-level Correlation LMS scheme is proposed through the analysis of conventional basic LMS based DFE and Correlation LMS algorithm and as compared with the conventional method, we can confirm the reduction of error propagation. When performing the computer simulation, as the Brazil channel model which is very popular for DTV broadcasting system is adopted, the result is drawn by comparing and analysing the equalizer algorithm. We have examine the symbol error rate which is in the range of 15~25dB of operation receipt SNR and MSE(Mean Square Error) in the DTV broadcasting system. As a result of comparing with the existing method, the signal-noise ratio which is necessary for maintain the bit error correction ability that the means of proposal is same is reduced by about 2~5dB, and in the rate of convergence through the MSE, we found the reduction of needed time.

• Journal of Broadcast Engineering
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• v.8 no.2
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• pp.153-162
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• 2003

This paper describes a structure of adaptive equalizer to improve reception performance of ATSC digital television (DTV) for 8-VSB receivers. There are many strong and dynamic echoes affecting reliable reception of DTV signal. Conventional DFE based least mean square (LMS) algorithm is readily implemented and has good Performance. There are still problems to be solved, however, in handling strong echoes and indoor reception. In this paper, structure of adaptive equalizer to mitigate these Problems in strong multipath interference conditions and indoor reception environment is first presented. Methods to reduce error propagation effects on DFE and initialization scheme of filter coefficients for fast convergence are then introduced. Computer simulation results prove that an adaptive equalizer with proposed design methods can combat with Brazil Ensemble and the Threshold of Visibility(TOV) is improved.