3GPP寬頻分碼多重進接傳輸信號處理及無線通道模擬之研討與在數位訊號處理器上的實現

Abstract

在3GPP寬頻分碼多重進接無線通訊系統中,輸入信號會經過傳輸端的處理並送進通道.通常傳輸訊號必須經過調變器的處理以利於在通道中傳輸.為了提高數據在接收端的正確性及區分不同的使用者,調變器使用編碼的方式來展頻訊號.在傳輸端及接收端間有許多種不同型式的通道.在這篇論文裡,我們根據3GPP上行傳輸之規格實現一個調變器,幾種不同通道的模擬器及一個接收濾波器.我們使用桌上型電腦為主控中心,一塊Innovative Integration 公司的Quatro6x DSP板用以實現整個上行傳輸系統.該DSP板共裝置四顆德州儀器公司出品的TMS320C67數位訊號處理器,我們使用一顆做調變器,一顆做通道模擬及一顆做接收濾波器.目前在一個使用者在多條路徑的穩定通道下,調變器及通道模擬器的處理速度可以達到每秒3.84百萬筆資料(chip).但在多重路徑Rayleigh淡化通道下,由於運算的複雜度無法及時處理完資料,可能的改進方法為簡化產生通道係數的複雜度並分配給多個處理器運算或在不影響結果的前提下將係數事先產生並重複使用.

In 3GPP Wideband-CDMA communication system, the purpose of the transmitter is to couple the message to the channel. It is often necessary to modulate the signal from the input transducer. For increasing the accuracy and distinguishing each user at receiver, the modulator provides coding method to spread. The channel, which can have many different forms, exists between the transmitting antenna and the receiving antenna. In this thesis, we implement a 3GPP WCDMA modulator, several kinds of channel simulator and a matched filter. A desktop PC acts as the controller, and an Innovative Integration Quatro6x DSP-embedded card is employed to implement the system. Four DSP chips of TI are placed on the board. We use one DSP chip for modulator, on chip for channel simulator and one for the matched filter. For the single user under static channel with multi-path, the processing speed of the modulator and channel simulator is 3.84M chips per second. But in Rayleigh fading channel, the data can not be processed on time because of the complexity. We suggest that we can decrease the complexity and part the function into more DSP chips or generate the channel coefficient if it does not influence the result.