在無線通訊系統中為了追求更高傳輸效能的透過結合和超寬頻(UWB)與多天線系統(MIMO)被賦予很高的期待。而改善相關的通訊品質和降低成本更是近幾年無線個人通訊網路中熱烈討論的議題。超寬頻主要是用在室內環境，但環境產生多路徑效應也影響著它的效能。多路徑效應造成的符際干擾(ISI)容易造成系統的錯誤率以及環境的失效率上升。因此，透過使用實數正交設計(ROD)可以有效的改善超寬頻多天線系統。首先，一個基地台可能在服務範圍內會上千移動通訊的使用者，而比較符合成本效益的做法是擴充基地的設備而不是在使用者端增加設計的成本。再來，使用實數正交設計的計算複雜度低也不需要將接收端的信號回授給傳送端。在這篇論文中，模擬環境透過使用射線彈跳追蹤法結合反複利葉轉換可以求出該環境的脈衝響應。因為模擬的頻譜相當大所對應到的時間解析度很高幾乎只有幾奈秒，我們考慮用耙式接收機(RAKE receiver)增加接收信號強度以抑制多路徑效應。再來，我們分析了超寬頻多天線系統使用不同實數正交設計方法的錯誤率效能。值得一提對於屋頂形狀研究相關研究是相對較少。在這篇論文的最後，我們比較了在使用不同維度的實數正交設計在不同模擬環境下的失效率(定義為錯誤率>10-6)。這個環境包含了常見的屋頂形狀包含平坦型、三角型、圓型、金字塔型以及梯形五種並討論了兩種材質。而我們得到在材質為鐵的平坦型屋頂會有最低的失效率，而這是因為在這個環境會有最嚴重的多路徑效應。 Ultra wideband (UWB) combined with multiple input and multiple output (MIMO) is expectable for satisfying high data rates in wireless communication. How to improve quality of communication and cost reduction have become hot research issues in wireless personal network. UWB is mainly applied to indoor environments characterized by multipath effect. Due to this effect, the inter-symbol interference that increases the bit error rate (BER) and outage probability of the UWB systems occurred. The application of real orthogonal design (ROD) in UWB-MIMO is beneficial. First, a base station may serves thousands of mobile end users. It seems more economical to add equipment to base stations rather than the mobile end user. Second, the transmitter does not require any feedback from receiver and its low computation complexity. In this thesis, the ray-tracing techniques and inverse fast Fourier transform are employed to get the impulse response of simulated environments. Based on the large bandwidth, the scale of time resolution is approximately several nanoseconds. So we take account of the RAKE receiver to increase received signal strength in order to reduce multipath effect. Then, analyzing the BER performance of the UWB-MIMO system when using ROD schemes with RAKE are briefly discussed.Significantly, fewer results are reported for the case of roof shaper. In this thesis intends to compare the outage probability for proposed scheme in different simulated environments. These five roof shapes including the flat shape roof, the triangular shape roof, the arched shape roof, the pyramid shape roof, and the mansard shape roof are constructed by materials of concrete and iron. As the result, we can conclude that the performance of outage probability with iron flat shape roof is better than the other shape roof with high order RAKE finger. Both for concrete and iron cases, it is found that the strong multipath effect for the flat shape roof is the largest.
