| 研究生: |
巫劭元 Wu, Shao-Yuan |
|---|---|
| 論文名稱: |
IEEE 802.16e 正交分頻多重存取系統之初步下行鏈路同步與細胞搜尋技術 Initial Downlink Synchronization and Cell Search for IEEE 802.16e OFDMA system |
| 指導教授: |
蘇賜麟
Su, Szu-Lin |
| 學位類別: |
碩士 Master |
| 系所名稱: |
電機資訊學院 - 電腦與通信工程研究所 Institute of Computer & Communication Engineering |
| 論文出版年: | 2009 |
| 畢業學年度: | 97 |
| 語文別: | 中文 |
| 論文頁數: | 35 |
| 中文關鍵詞: | 正交分頻多重存取 、下行鏈路 、細胞搜尋 |
| 外文關鍵詞: | Cell Search, Downlink, OFDMA |
| 相關次數: | 點閱:56 下載:1 |
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無線寬頻存取很重要的一個步驟,是下行(Downlink)鏈路剛建立時接收端所必須做的初步的時間、頻率同步以及搜尋目前所屬的基地台(cell)。IEEE 802.16e OFDMA系統不同於WirelessLAN等傳統OFDM系統,其preamble在時域上沒有完美的週期性可用來做時間同步,加上所使用的PN code種類多,長度長,傳統的偵測Cell ID方法複雜度很高。在此篇論文中,我們利用IEEE 802.16e OFDMA系統的Preamble頻域架構以及OFDM訊號特性,除了偵測Frame的起始點及Cell ID,同時估測出整數及小數頻率偏移,達到頻率同步,此方法主要可降低cell search的運算量及加快收斂速度,並提高時間同步的準確度。
For broadband wireless access, it is very important that the mobile station (MS) has to perform initial synchronization and cell search when setting up the downlink transmission. The IEEE 802.16e OFDMA system is different from conventional OFDM systems like WLAN. Its time-domain preamble does not have perfect periodicity for time synchronization. And the complexity of the conventional Cell ID identification method is very high due to a large number of long preamble PN codes. In this paper, we utilize the property of its preamble’s frequency-domain structure and that of an OFDM signal to achieve frame detection and Cell ID identification. Meanwhile we also estimate the integer and fractional frequency offset, thus accomplishing the frequency synchronization. This method can reduce the complexity in Cell ID identification and improve the frame detection accuracy.
[1] IEEE std 802.16-2004. IEEE Standard for Local and Metropolitan Area Networks–Part 16: Air Interface for Fixed Broadband Wireless Access Systems, Oct. 2004.
[2] Draft IEEE std 802.16e/D9. IEEE Standard for Local and Metropolitan Area Networks–Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, June 2005.
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