本文利用市面上兩種常見的軟體定義無線電 ( SDR ) 平台，RTL-SDR 與 USRP 來實現真實 LTE / LTE-A 下行同步與細胞搜尋。分析規格內建之符幀架構，採純軟體方式偵測基頻樣本內之主要同步信號 ( PSS ) 與第二同步信號 ( SSS )，並完成載波頻率誤差 ( CFO ) 校正與時間同步來達到初始細胞搜尋之目標。輔以矽智產 ( silicon IP ) 硬體特性之了解，加以消除真實環境接收信號的非理想效應，如脈衝雜訊、直流 ( DC ) 成分與 IQ 不匹配，來維持正交分頻多工 ( OFDM ) 架構之平行通道的概念。;Using 2 types of the most popular software-defined ratio ( SDR ) platform, RTL-SDR and USRP, to design and implement a real world LTE / LTE-A downlink synchronization and cell search receiver. According to the specification of frame structure, it can detect primary synchronization signal ( PSS ) and secondary synchronization signal ( SSS ) from baseband samples by pure software methodology. In order to accomplish cell search target, carrier frequency offset ( CFO ) calibration and timing synchronization were also finished. After understanding characteristics of SIP ( silicon IP ) hardware, mitigating the non-ideal effects of real world condition, i.e. impulse noise, direct current ( DC ) and IQ mismatch, to maintain parallel channel concepts of orthogonal frequency-division multiplexing ( OFDM ).
