在混合式衛星-地面網路中放大後傳送合作式通訊之研究

Studies on Amplify-and-Forward Cooperative Communications in Hybrid Satellite-Terrestrial Networks

周星宏(Sing-Hong Jhou)

指導教授 ： 溫志宏

共同指導教授 ： 許孟烈(Meng-Lieh Sheu)

國立暨南國際大學/科技學院/通訊工程研究所/碩士(2011年)

https://doi.org/10.6837/NCNU.2011.00320

摘要

合作式通訊利用了空間多樣性的概念仿效了多輸入多輸出的通訊系統，利用中繼站的協助，使得傳輸資訊更為可靠、傳輸率更高，相較於多輸入多輸出的系統中，更能減少硬體設計上的複雜度及降低所需花費成本。而近年來無線通訊發展過程中，藉由合作式多跳耀中繼站輔助技術方法改善了系統效能和無線系統的服務範圍，並利用中繼站當成虛擬天線使得系統達到分集增益(Diversity)並改善鏈路可靠性。
本論文主要探討在混合式衛星-地面網路中，考慮下鏈合作式通訊系統，且中繼站使用放大後傳送策略(Amplify-and-Forward, AF)合作式通訊，系統架構包含一個來源端、一個中繼站及一個目的端，再根據所提出來的通道環境，來找出在目的端使用最大比率合成(Maximal Ratio Combining, MRC)技術結合後訊號之訊號與雜訊比(Signal-to-Noise Ratio, SNR)的機率密度函數(Probability Density Function, PDF)來分析此系統，再根據此PDF進而去計算在目的端所接收SNR的動差生成函數(Moment Generating Function, MGF)，來獲得M-QAM的平均符元錯誤機率(Average Symbol Error Probability, ASEP)。
最後，我們將研究議題延伸至在單一個來源端、多個中繼站及單一個目的端的系統架構，進而去探討在多個中繼站中，透過中繼站選擇方式，選出最好的中繼站做傳送(S-AF)，使在目的端的SNR達到最大。
上述每個議題皆會使用電腦模擬來驗證我們所推導的式子。

關鍵字

合作式通訊 ； 放大後傳送策略 ； 瑞雷衰減 ； 萊斯衰減 ； 平均符元錯誤機率

並列摘要

Cooperative communication uses the concept of space diversity to follow the multiple-input multiple-output communication system. The uses of relay stations make the transmission more reliable and higher data rate. Compared with the multi-input multi-output system, cooperative communication can reduce the hardware design complexity and cost. In recent years the development of wireless communication, the cooperative multi-hop relay station assisted technologies improve the performance and services range of wireless systems, and the use of relay stations a virtual antenna for diversity gain improve the link reliability.
In this thesis, we study the downlink cooperative communication systems of hybrid satellite-terrestrial networks. The system architecture includes a source, a relay station with Amplify-and-Forward (AF) strategy and a destination. According to the proposed channel environment, we derive analytical expressions for the probability density function (PDF) and the moment generating function (MGF) of receiver’s signal-to-noise ratio (SNR) at the destination, to obtain the average symbol error probability (Average Symbol Error Probability, ASEP) of M-QAM.
Finally, we extend the issue to the environment with a single source, multiple relay stations and single destination. To maximum the SNR at the destination, the selection the best relay stations for amplify-and-forward (S-AF) is explored for multiple relay stations. The formula derived for each of the issues in this thesis are verified by using the computer simulation.

並列關鍵字

cooperative communication ； amplify-and-forward ； rayleigh fading ； rician fading ； average symbol error probability

參考文獻

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