寬頻分碼多工系統上行同步之模擬與DSP設計

Abstract

展頻通訊的傳送端與接收端必須要碼同步。 碼同步的任務可藉由碼擷取(Code acquisition) 器和碼追蹤 (Code tracking) 迴路來達成與維持。 本論文首先探討具有非同調後偵測積分器 (Post-detection integration)之碼擷取演算法。 接著介紹具有波整形頻寬限制器之非同調超前-滯後碼追蹤 (Early-late code tracking) 迴路。 應用這兩種演算法在第三代行動通訊標準3GPP/UTRA FDD 之上行碼傳輸同步處理。 經由電腦的模擬與驗證，我們可以瞭解上述之碼同步演算法，在加成性白色高斯雜訊 (AWGN) 通道與時變通道下之性能表現。 最後，我們使用Blue Wave System 的TMS320C6201 DSP板來實現碼同步演算法之即時處理。

Spread-spectrum communication requires that the transmitter and receiver spreading waveforms be synchronized. The task of achieving and maintaining code synchronization could be completed by two components: code acquisition and code tracking. In this thesis, first a matched filter acquisition algorithm with noncoherent post-detection integration (PDI) scheme is discussed. Then a noncoherent early-late code tracking algorithm with bandlimited-pulse shaped chips is presented. All these synchronization algorithms are focusing on the uplink of 3GPP/UTRA FDD wideband CDMA system. The performances of each algorithm are obtained by simulations over both AWGN and time-varying channels. Finally, these synchronization algorithms are implemented with a Blue Wave System’s TMS320C6201 DSP board to realize the real-time processing.