- 學位論文
二維與三維通道模型於空中救災通訊系統的研究
Study on Two-Dimensional and Three-Dimensional Channel Models for Rescue Communication System via Aerial Platforms
摘要
當災區內通訊中斷，使用飛行器搭載中繼系統，作為臨時基地台是一個可行的方案。此外，考慮災區人員較多，為了增加通道容量，中繼器將使用多天線的多輸入多輸出(MIMO)系統。本文模擬災區的無線通道特性，首先估測MIMO中繼通道的功率損耗，以制定中繼系統的最大功率增益，其次為評估2x2x2通道系統的通道容量。一般的二維無線通道模型在平面上建模，無法考慮中繼站的高度，與災區障礙物的高低起伏。本文引用文獻的模型去建構一個二維通道模型與一個三維通道模型，並比較兩者的模擬結果。三維通道模型加入了中繼站高度與災區障礙物的高度分佈。 在本文的模擬中，將設定幾種災區通訊的環境，並使用兩種通道模型來估測功率損耗、通道的空間相關係數，以及遍歷性通道容量。最後將根據結果，得知在吾人設定的通道環境下，使用二維通道模型與三維通道模型的差別不明顯。
並列摘要
When communication is disable in the disaster areas, using relay system via aerial platforms as a temporary base station is a viable solution. Furthermore, we consider that there are a lot of people in the disaster areas. In order to in-crease channel capacity, relay station equipped with multiple-input multi-ple-output(MIMO) system is required. In this paper, the wireless channel characteristics were simulated. First, we studied the signal fading in the channel to evaluate the gain needed in the relay system. Secondly, we estimate channel capacity of 2x2x2 MIMO relay channel system. The typical two-dimensional wireless channel modeling on the plane can not be considered the height of the relay station and undulating height of the disaster obstacle. According to the reference models, a two-dimensional and a three-dimensional relay MIMO channel models are modeled to compare estimate results of both model. The height of the relay station and height distribution of the disaster obstacle are joined in three-dimensional channel model. In the simulations of this paper, we set several conditions for the disaster communications. Two kinds of proposed model are used to estimate path loss, spatial correlation coefficient ,and ergodic capacity. Based on the results , the data differences between using two-dimensional model and using three-dimensional are not significant in our applications.