• Title/Summary/Keyword: open-loop MIMO

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Performance Evaluation of Octonion Space-Time Coded Physical Layer Security in MIMO Systems (MIMO 시스템에서 옥토니언 시공간 부호를 이용한 물리계층 보안에 대한 성능 분석)

  • Young Ju Kim;BeomGeun Kwak;Seulmin Lim;Cheon Deok Jin
    • Journal of Broadcast Engineering
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    • v.28 no.1
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    • pp.145-148
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    • 2023
  • Open-loop Octonion space-time block code for 4 transmit antenna system is considered and random phases are applied to 4 transmit antennas for physical layer security. When an illegal hacker estimates the random phases of 1 through 4 transmit antennas with maximum likelihood (ML), this letter analyzes the bit error rate (BER) performances versus signal-to-noise ratio (SNR). And the Octonion code in the literature[1] does not have full orthogonality so, this letter employs the perfect orthogonal Octonion code. When the hacker knows that the random phases are 2-PSK constellations and he should estimate all the 4 random phases, the hacking is impossible until 100dB. When the hacker possibly know that some of the random phases, bit error rate goes down to 10-3 so, the transmit message could be hacked.

A Transmit Power Control based on Fading Channel Prediction for High-speed Mobile Communication Systems (고속 이동 통신 시스템을 위한 페이딩 예측기반 송신 전력 제어)

  • Hwang, In-Kwan;Lee, Sang-Kook;Ryu, In-Bum
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.1A
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    • pp.27-33
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    • 2009
  • This paper proposes transmit power control techniques with fading channel prediction scheme based on recurrent neural network for high-speed mobile communication systems. The operation result of recurrent neural network which is derived interpretively solves complexity problems of neural network circuit, and channel gain of multiple transmit antenna is derived with maximum ratio combining(MRC) by using the operation result, and this channel gain control transmit power of each antenna. simulation results show that proposed method has a outstanding performance compared to method that is not to be controlled power based on channel prediction. Most of legacy studies are for robust receive technique of fading signals or channel prediction of fading signals limited low-speed mobility, but in open loop Power control, proposed channel prediction method decrease system complexity with removal of fading effect in transmitter.