衛星廣大的廣播覆蓋特性使其容易受到竊聽攻擊。攻擊者可以透過攔截目標終端用戶(User Terminal (UT)) 的通道狀態資訊(Channel State Information (CSI)) 來發起嗅探攻擊(Sniffing Attack)。CSI在UT端的導頻符號(Pilot Symbol) 上做估計，然後回傳給衛星。在嗅探攻擊中，攻擊者通過攔截的CSI計算偽造的CSI，然後回傳給衛星以誤導衛星上的迫零預編碼(Zero-forcing Precoding)。現有的CSI 保護方法不適用於採用自適應調製與編碼(Adaptive Modulation and Coding (AMC)) 技術的衛星地面網絡。在本文中，我們提出了一種抵抗嗅探攻擊的方法，SSC，以抑制衛星地面網絡中的CSI洩漏。實驗結果表明，我們的方法在專用導頻(Dedicated Pilot)和公用導頻(Public Pilot) 場景下都能更有效地抵抗嗅探攻擊。;Satellite’s wide broadcasting coverage property make it vulnerable to eavesdropping attacks. Attacker can launch sniffing attack by intercepting the channel state information (CSI) of the target user terminal (UT). CSI is estimated on pilot symbol at UT side and then feedback to satellite. In sniffing attack, attacker calculates forged CSI by the intercepted CSI, then feedback to satellite to mislead zero-forcing precoding on satellite. Existing CSI protection schemes are not applicable to satellite-terrestrial network which adopting adaptive modulation and coding technique . In this thesis, we propose a sniffing attack resisting scheme, SSC, to suppress CSI leakage for satellite-terrestrial networks. Simulation results show that our method can more effectively resist the sniffing attack under both dedicated pilot and public pilot scenarios.
