適用於衛星通訊之跨層(Cross-Layer)演算法設計

Abstract

近幾年來在政府有計畫的主導下，已使我國積極地朝向「發展自主衛星的目標」大 步邁進，現階段不但已建立Ku 頻段（12 GHz-14 GHz、使用頻寬為500 MHz）衛星通 信技術，並開始著手研發Ka 頻段（20 GHz-30 GHz、使用頻寬為2500 MHz）同步軌道 通信衛星的系統設計，屆時將可提供電視廣播、電話、傳真、視訊會議及行動通信等電 信服務，奠立我國成為亞太營運中心－電信多元化與自由化的礎石；一個完善之衛星通 信系統之構建，除了衛星本體的發展外，尚需有完整的地面站台網路規劃與之配合，方 能將其效益淋漓盡致的發揮，而地面網路規劃往往是以善用通信資源及配合運用需求為 導向，因此為配合需求單位衛星通信所需，符合未來衛星通信發展趨勢，研究高效率的 衛星傳輸鏈路是十分重要的課題。 本計畫將針對國內目前衛星通信發展現況，以Ku 或Ka 頻段之衛星通信為參考 主體，基於正交分頻多工網路架構，研究於Ku 或Ka 頻段衛星通信之降雨衰減效應， 並建立雨衰分析模型，同時結合適應性調變編碼技術與混合式自動重傳機制(HARQ)提 出一套嶄新之PHY-MAC 跨層(cross-layer)收發機架構，藉由PHY 層與MAC 層之聯合 設計達到優異之雨衰補償效果，最後吾人將建立全系統之軟體模擬平台進行訊號處理演 算法驗證及效能評估，期能建立符合未來商業高效率運用或軍事強韌性運用所需之衛星 通信鏈路。

Currently, with the great supports of the government, the development of the state-owned satellite communication system is being speeded up. The Ku-band (12 GHz-14 GHz, with the bandwidth being 500 MHz) satellite communication technologies have been built up, and then more attentions will be focused on the design of the Ka-band (20 GHz-30 GHz, with the bandwidth being 2500 MHz) synchronous satellite communication system. With such a system constructed, a lot of multimedia services, such as TV broadcasting, telephony, fax, video conferencing, mobile communications, etc., will be provided to establish our country as a telecommunication service center in the Asia Pacific Region – a founding stone of communication diversification and liberalization. To develop a satisfactory satellite communication infrastructure, completed ground station planning is a must, in addition to the design of satellite itself. Since the ground station planning aims to efficiently utilize communication resources and meet application requirements, it is an important task to cooperate with the request organization to design a highly efficient satellite communication system for keeping up with future satellite communication trends. In this project, based on the current domestic Ku- and Ka-band satellite communication development situations, we will research into the effects of rain attenuation on OFDM-based satellite communication links and will develop a rain attenuation analysis model. Moreover, a new PHY-MAC cross-layer transceiver architecture, which combines adaptive modulation/coding scheme with hybrid ARQ (HARQ) technique, will be proposed. Through joint design of PHY- and MAC-layer algorithms, the proposed transceiver is expected to provide excellent rain attenuation compensation. Finally, we will develop an overall software simulation platform to verify the established signal processing algorithms and evaluate the system performance, in order to develop a robust satellite communication link for commercial and military applications.