臺灣博碩士論文加值系統

　　隨著通信技術不斷的進步，從有線通信到無線通信，為了能夠節省有限的頻寬資源、提供高質量通信服務並能抵抗頻率選擇性衰減通道，正交分頻多工技術(Orthogonal frequency-division multiplexing, OFDM)的推出解決許多問題。本論文利用傅立葉轉換的技術對接收到的訊號作後處理，再利用通道模型的公式作通道估測來推算通道響應值，來觀察通道。
　　本論文使用軟體無線電（Software Defined Radio, SDR）平台來取代向量網路分析儀來接收分析訊號和訊號產生器發送訊號，以降低實作之成本。以OFDM將訊號分成數個子載波來傳送資料，再以SISO-OFDM系統在數個不同環境通道中做模擬，使用NI LabVIEW Communication軟體開發工具和通用軟體無線電週邊設施(Universal Software Radio Peripheral, USRP)，設計與實現傳輸測試平台分析通道，接而利用Matlab分析訊號，進而求出通道響應值來觀察通道。使用軟體定義無線電平台開發不僅能實際做訊號收發功能並能大幅降低成本，其另外優點是移動性方便，未來可以利用此平台擴增天線數量已達到大量資料的傳遞。

With the develop of communication technology, from wired communication to wireless communication, in order to save the limited bandwidth resource, provide high quality communication service and resist frequency selective fading channel, Orthogonal frequency-division multiplexing technique is presented to solve many problems. In this thesis, the technique of Fourier transform is used to deal with the received signal, and then the channel estimation of channel response is calculated by using the formula of the channel model to observe the channel.
In this thesis, a software defined radio (SDR) platform is proposed to replace the spectrum analyzer to receive the analysis signal and the signal generator to send the signal to reduce the cost of the test. OFDM is divided into several subcarriers to transmit data, and then SISO-OFDM system in a number of different environmental channels to do the simulation, the use of NI LabVIEW Communication software development tools and general software radio peripheral equipment (Universal Software Radio Peripheral, USRP) Design and implementation of the transmission test platform analysis channel, then use Matlab to analyze the signal, and then find the channel response to observe the channel. The use of SDR platform development can not only do the actual signal transceiver function and can significantly reduce costs, the other advantages of mobility is convenient, the future can use this platform to expand the number of antennas to reached a large number of data transmission.

摘 要 i
英文摘要 iii
致 謝 iv
目錄 v
圖目錄 vii
表目錄 ix
第一章　序論 1
1.1　研究背景 1
1.2　研究動機 2
1.3　論文架構 2
第二章　OFDM系統架構 4
2.1　OFDM基本原理 4
2.2　通道量測基本架構 6
2.3　載波間的正交性 8
2.4　反快速傅立葉與快速傅立葉 8
2.5　保護區間與循環字首 9
第三章　通道估測 11
3.1　簡介 11
3.2　多重路徑干擾11
3.3　通道模型 13
3.4　通道估測 14
第四章　實作設計與模擬結果分析 16
4.1　軟體定義無線電 16
4.1.1　NI通用軟體定義無線電週邊設備 17
4.1.2　USRP-2952R 18
4.1.3　USRP-2952R硬體設置 20
4.2　SISO SDR 系統設計 21
4.2.1　SISO OFDM SDR 系統設計 21
4.3　實作系統架構 24
4.4　擷取的資料 26
4.5　Matlab資料後處理 27
4.6　結果分析 28
第五章　結論 31
參考文獻 32

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