載波頻率偏移以及頻率相依之實虛部不平衡為寬頻直接轉換接收器中常見之非理想效應，前者會使接收訊號產生相位偏移，後者則會使接收訊號受到頻譜上的鏡像訊號干擾，兩者皆對接收端錯誤率有顯著的影響。文獻中估計載波頻率偏移之演算法，大多未考慮頻率相依之實虛部不平衡之影響，因此常導致估計準確度降低。本篇論文針對頻率相依之實虛部不平衡的直接轉換接收器，提出一種估計載波頻率偏移之方法。其方法為使用廣義週期性領航序列，並對接收訊號進行ESPRIT分析後，以得到載波頻率偏移之估計值。模擬結果顯示，此方法在不同的實虛部不平衡情況下，可有效估計載波頻率偏移。

Carrier frequency offset (CFO) and frequency-dependent I/Q imbalance (FD IQI) are well-known non-ideal effects of the broad band direct conversion receivers. The former may cause phase rotation of the received signals, and the latter results in image frequency interference on signal spectrum. Both of them significantly degrade the error rate of the receiver. Most of the CFO estimation techniques in the literature do not consider the effect of FD IQI, resulting in inaccurate CFO estimation. In the thesis, we consider CFO estimation in the presence of FD IQI. The method uses the generalized periodic pilot (GPP) sequence as the training sequence, and applies the Estimation of Signal Parameters by Rotational Invariance Techniques (ESPRIT) to the received signals to obtain the CFO estimate. Simulation results demonstrate that the proposed method accurately estimates the CFO in different scenarios of FD IQI.

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