• Title/Summary/Keyword: Spread spectrum (SS)

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Improvement of DS Simple Reception System for Advance of Duty Rate on Meteor Burst Transmission Path (유성 버스트 전송로의 도통을 향상을 위한 DS 간이 수신시스템의 개선)

  • Kwon Hyeog-Soong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.11A
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    • pp.1073-1080
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    • 2005
  • In spite of many advantages of Meteor Burst Communications(MBC) on its transmission channel, the fact that its duty rate is less than 10 percents is a considerable deficiency of MBC. To overcome with this deficiency without paying large cost, we use a direct sequence(DS) simple reception system. This method doesn't need to add the components for acquisition or tracking the signal so that it keeps the cost efficiency of the MBC. But it has a disadvantage that its duty rate shows a large decline by noise. For this problem, we adopt the proposed system applying a positive feedback circuit. The improvement by this method is more significant when the received signal is weak. Simulation results show as tl is l00ms, then the burst length would be increased by $35\%$ when the initial value of the received signal power increases by 3 dB, t2 is 135ms. If the power increases by 6dB the burst length would be 170ms thus increased by $70\%$, which shows a great enhancement. Suppose now that tl is 50ms and the power is increased by 3dB, then t2 would be increased by $70\%$ to 85ms, and increasing the power by 6dB it would be increased by $130\%$ to 115ms.