第五代行動通訊系統之通道估計與資料偵測方法之研究

Abstract

在未來十年，現有的通訊標準明顯已不符合未來所需。為了因應這個問題，我們研究第五代的蜂巢式系統可能的技術之一，也就是巨量多輸入單輸出(Massive MISO)空間多工(SDMA)系統。本論文研究用於第五代行動無線通訊系統的通道估計和資料偵測的方法，我們分別在上行（UL）採用犁耙式接收機(RAKE receiver)，在下行（DL）採用犁耙式傳送機(Pre-RAKE transmitter)，然後使用不同的領航訊號結合資料訊號作為我們在上行的傳送訊號，並且在基地台（BS）端估計通道。我們加上平行干擾消除（PIC）的方法，能使得位元錯誤率（BER）可以有很好地改善。此外，我們還討論一些提高平行干擾消除效能的方法，像是用不同的通道估計選擇方法、增加軟判定裝置、對於某些使用者訊號做時間提前。接著在下行時，我們可以用這些通道訊息在基地台端建立犁耙式傳送機，傳送資料訊號給每個用戶。最後，我們透過電腦模擬進行效能的分析。

In next ten years, existing communication standards obviously cannot meet with desirable future need. In response to this, we research on one of the possible techniques in 5G cellular system, which is massive multiple-input single-output (Massive MISO) spatial division multiple access (SDMA) system. In this thesis, channel estimation and data detection methods for Massive MISO SDMA system of 5G mobile radio communications are investigated. We adopt RAKE receiver in uplink (UL) and Pre-RAKE transmitter in downlink (DL) in our system respectively. We use different pilot sequences combined with data sequence as our transmitted signal in UL and estimate channels at base station (BS). With parallel interference cancellation (PIC) method, bit error rate (BER) can be improved further. Besides, we also discuss the effect of different path selection methods, feasibility of soft decision devices and time advance method for some users’ signals in order to improve the performance of PIC. Then, in DL, we can use these channel information to build the Pre-RAKE transmitter at BS and transmit signal to each user. Finally, the performances are demonstrated through computer simulation.