正交分頻多重接取上鏈系統與干擾之載波頻率偏移估測

Carrier Frequency Offset Estimation with Interference for OFDMA Uplink Systems

陳建中(Chien-chung Chen)

指導教授 ： 陳永芳

國立中央大學/資訊電機學院/通訊工程學系/碩士(2015年)

摘要

在最近幾年，無線蜂窩網路系統的普及使得對更高容量和數據傳輸速率的需求日益增加，異質網路系統因應而生。而載波頻率偏移(CFO)一直是正交分頻多重接取(OFDMA)上鏈系統中一個具有挑戰性的問題，其肇因為都普勒偏移亦或傳輸與接收之間震盪器不匹配，進而引發載波間干擾(ICI)與多重接取干擾(MAI)，導致系統效能嚴重衰減。
在本篇論文中，我們模擬異質網路的環境，利用正交分頻多重接取系統(OFDMA)，進行載波頻率偏移估測。我們提出一個具有抗干擾能力的載波頻率偏移估測方法，我們經由旋轉不變性技術估計信號參數(ESPRIT)與平滑技術(Smoothing technique)進行估測。在模擬結果中也驗證了這個方法的效能且估測結果接近Cramér-Rao Bound。

關鍵字

異質網路 ； 正交分頻多重接取系統(OFDMA) ； 載波頻率偏移(CFO) ； 旋轉不變性技術估計信號參數(ESPRIT) ； 平滑技術(Smoothing technique) ； Cramér-Rao Bound

並列摘要

In recent years, the increase in popularity of wireless cellular networks makes the rising demand for higher capacity and data rate. This change results in Heterogeneous networks emergency. In this proposed method, heterogeneous network environments in orthogonal frequency division multiple access (OFDMA) are constructed for the simulation to verify the efficacy of the proposed scheme. We proposed a carrier frequency offset (CFO) estimation algorithm with strong interference resistant capability for OFDMA systems. We use the rotational invariance technique (ESPRIT) and smoothing techniques as our estimator. In the simulation results, they demonstrate the effectiveness of this method and the results are close to Cramér-Rao Bounds.

參考文獻

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