OFDM系統在不同環境下的性能分析

Performance analysis of OFDM system under different environvments

鍾以辰(Yi-Chen Chung)

指導教授 ： 鄭立德

中原大學/電機資訊學院/通訊工程碩士學位學程/碩士(2020年)

https://doi.org/10.6840/cycu202000366

摘要

我們探討了正交分頻多工(Orthogonal Frequency Division Multiplexing)在各種環境下的性能比較，OFDM在目前4G、5G通訊系統中，扮演著重要的腳色。為了因應日新月異的通訊設備以及使用者不斷增加的趨勢，我們必須想辦法透過通訊系統來更快速及準確的傳達需要傳送與接收的資訊。在未來不只是的5G甚至更新穎的通訊系統，OFDM便是一個穩定的基礎讓我們可以往下去延伸。
在本論文中，我們不僅僅使用一般的OFDM系統，加入了循環字首前綴(Cyclic Prefix)以及使用Offset QAM，來使我們的OFDM系統具有更好的效能及穩定性。為了達到更好的頻譜效率以及最小化傳輸過程中符號位元區間與通信通道的干擾，加入了幾種脈衝濾波器(Pulse Shape Filter)，同時在COST207的環境下去探討及分析性能，研究這項技術是否適合未來的通訊系統需求，希望能為未來的通訊發展有相關幫助。

關鍵字

正交分頻多工 ； 循環字首前綴 ； COST207模擬通道 ； 瑞雷衰減通道 ； Pulse Shape Filters

並列摘要

We explore the performance of the Orthogonal Frequency Division Multiplexing in different environments, OFDM plays an important role in the current 4G and 5G communication systems. In order to cope with the rapid progress communication equipment and users keep growing trend, we must figure out ways to transmit and receive the data faster and increase data’s accuracy. Not only next generation 5G, even the latest communication systems, OFDM is the stable foundation that allow us to extend.
In this paper, we not only use the general OFDM system, we added the
Cyclic Prefix and Offset Quadrature amplitude modulation to make our OFDM
systems have better performance and stability. In order to make the spectral
efficiency better and minimize the interference between symbols and channels,
several kinds of Pulse Shape Filter have been added, and the performance is
discussed and analyzed in the COST207 channel. Study whether this technology
is suitable for future communication system needs, hope to help the
development of communication in the future.

並列關鍵字

OFDM ； Cyclic Prefix ； COST207 Channel Model ； Rayleigh Fading ； Pulse Shape Filter

參考文獻

[1] 4G LTE關鍵技術介紹-OFDM https://kknews.cc/zh-tw/tech/e9epgan.html

[2] FFTIFFT演算架構 OFDM提高LTE頻譜使用效率https://www.2cm.com.tw/2cm/zh-tw/tech/791ABBFB070B4F1B82E42E01C86719C0

[3] MIMO-OFDM http://wshnt.kuas.edu.tw/network/n1/MIMO%20OFDM.htm

[4] J. Du and S. Signell, “Novel Preamble-Based Channel Estimation

[5] M. Failli, “Digital Land Mobile Radio Communications. COST 207,”in Office for Official Publications of the European Communities, Final report, Luxembourg, 1989.