• The Journal of the Korea Contents Association
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• v.13 no.4
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• pp.23-34
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• 2013

This study would verify the validity of two transmission technology, 'Clear QAM' and '8VSB'. 'Clear QAM' and '8VSB', the transmisson technology, have been suggested as the concrete alternatives in the situation that half of subscriber of multi channel tv service have been still out of benefit from digital convert. In this study, we have shown that the introduction of 'Clear QAM' and '8VSB' should ease economical burdens and information minority group without extra set-top box. But there is another concern that it should negatively affect on the contents industry by a devaluation of the multi channel tv service or by an infringement of copyright. In these reasons, it is still difficult to solve the related concern, though the government have to set up the politic goal for the related industry as well digital convert. This study suggested that Korea Communication Commission consider above-mentioned technology temporarily, and reconsider 'Clear QAM' around the completion of the digital convert project.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.4
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• pp.76-85
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• 2008

In this paper, a 800 MHz 1 W cartesian feedback linearized power amplifier is designed and fabricated for TETRA handset application. For amplification of TETRA signal with 200 kHz narrow bandwidth, amplifier linearization performance of more than 30 dBc is improved through the cartesian feedback linearizer at the offset Sequency of ${\pm}25$ kHz. It is clear that the linearization performance is affected by imbalance of gain and phase between I/Q signals and also DC offset. The linearization performance can be maximized by the compensation of those influences. Cartesian feedback is suitable for a liearization technique of narrow band signal with QAM and another modulation signals, as well.