二維犁耙式接收機與多用戶偵測器相結合之研究

Abstract

在這一個子計畫中，我們將結合二維犁耙式接收機及多用戶偵測器，來設計一個具有高系統容量的接收機架構。這一個接收機是一個多層級平行多用戶接收機。每一層級，我們仍使用以快速傅立業轉換為基礎之時空（二維）匹配濾波器為基礎架構來實現資訊偵測、信號重建及通道估計等功能。在每一層級，我們消去由上一層級重建信號，因而可以減少干擾，並且提高系統容量。又此接收機架構具有時空匹配濾波器，我們可以將接收信號以空間及時間的最大比相加，而得到時空信號處理增溢。最後我們將以電腦模擬的方法，驗證這一個二維犁耙式接收機與多用戶偵測器相結合之架構在來自不同角度的多重路徑衰減通道的表現，並估計其增加的系統容量。

In this project, we will propose a new receiver architecture which integrates a 2D RAKE receiver with a multiuser detector in order to obtain higher capacity for a wide-band CDMA system. The proposed receiver architecture adopts a multistage structure to cancel multiple access interference (MAI) in parallel. In each stage, we use a set of FFT-based 2D matched filters to achieve code despreading, channel matching, MAI reconstruction, and channel sounding. The reconstructed MAI's of a stage are removed from the received signal to obtain a "cleaner" signal for data detection in the next stage. Moreover, this receiver architecture performs spatial-temporal channel matched filtering with maximal-ratio combining. The integration of spatial-temporal processing with multiuser detection further increases the system capacity. We will use computer simulations to evaluate the system performance with a spatial-temporal multipath fading channel model and estimate the system capacity.