隨著無線通訊技術的發展，相位陣列常被用來實現波束成形(beamforming)，然而其內部之功率放大器陣列(power amplifier array)具有非線性效應，會造成頻譜增生(spectral regrowth)，進而影響鄰近頻帶之訊號。因此本論文使用預失真器的概念，並根據文獻中的間接學習架構，結合峰值因數削減方法，補償功率放大器陣列因非線性效應所產生之問題，以達到線性化之目的。根據多天線系統之陣列功率放大器(PA array)與波束成形的概念，我們於本論文中推導等效傳送、接收訊號模型與相位陣列之關係，並據以提出其所對應的數位預失真演算法。我們以模擬方式探討所提出之演算法對於不同方向接收用戶的訊號改善效果，模擬結果顯示所提出之演算法能有效補償功率放大器之非線性效應，其訊號品質改善效果更優於傳統僅使用單一功率放大器進行預失真器訓練的做法。

With the development of wireless communication technology, phased arrays have often been used to realize beamforming. However, the internal power amplifier (PA) arrays exhibit non-linear effects, which cause spectral regrowth and results in interference to adjacent bands. In the thesis, we use the crest factor reduction (CFR) method with digital pre-distortion (DPD) that is based on the indirect learning architecture in the literature to compensate for the nonlinear effects of the PA arrays and achieve linearization. Considering the concepts of PA arrays and phase-shifter-based analog beamforming in multi-antenna system, we derive the equivalent transmitted and received signal models, and use them to derive the corresponding DPD algorithm. We use simulations to study the linearization performance of the proposed algorithm for users located in different directions. The simulation results show that the proposed algorithm can effectively compensate for the nonlinear effect of the PA arrays. With the proposed linearization method, the improvement of signal quality (over the case that does not use linearization) is significantly better than that of the traditional method that uses only a single PA in the array to train the pre-distorter.

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