上行正交分頻多工存取系統之載波頻率偏移估測研究

Study on the CFO estimation for OFDMA uplink transmission

黃馨儀(Hsin-Yi Huang)

指導教授 ： 魏學文

國立暨南國際大學/科技學院/通訊工程研究所/碩士(2007年)

https://doi.org/10.6837/NCNU.2007.00095

摘要

在正交分頻多工接取(orthogonal frequency division multiple access，OFDMA)系統中，採用interleaved子載波配置方式可以提供較大的頻率分集並增加在頻率選擇性通道抗衰減(fading)的能力。但是此配置方法易受載波頻率偏移(CFO)破壞其正交性而產生較大的MAI，以致於很容易產生mismatch問題。本論文針對傳統的uplink OFDMA CFO估測方法提出兩個改良式的CFO估測方法，方法一利用iteration和平均的觀念，方法二在每次的遞迴中合併使用多重存取干擾消除(MAI cancellation)的程序，模擬證明此兩種方法均可大幅改善估測準確度避免mismatch情況發生並且在很高的fading rate上也可以表現的很好。

關鍵字

正交分頻多工接取 ； 上行 ； 載波頻率偏移

並列摘要

In OFDMA, an interleaved subcarrier-assignment scheme provides maximum frequency diversity and increases the capacity in frequency-selective fading channels. Carrier-frequency offsets (CFOs) between the transmitter and the receiver destroy the orthogonality and introduces ICI, resulting in multiple-access interference. This thesis proposed two Modified CFO algorithm, one utilize iteration and average, the other use multiple access interference (MAI) cancellation strategy in every recursion to improve estimation performance of conventional method. The presented algorithm can have good performance through complete simulations.

並列關鍵字

OFDMA ； uplink ； CFO

參考文獻

參考文獻

[1] "IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems", IEEE Std. 802.16-2004

[2] IEEE Std 802.16e-2005, 2006. Standard for Local and metropolitan area networks Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands and Corrigendum 1, IEEE, New York, USA.

[3] 3GPP, “Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN),” Tech. rep. 25.913, http://www.3gpp.org.

[4] Richard van Nee, Ramjee Prasad, OFDM wireless multimedia communication, Artech House Boston London, 2000.