高速移動下之無線傳輸訊號處理技術研究

Abstract

本計畫研究在高速移動下，採正交分頻多工調變之數位無線通訊的訊號接收技術。 其中考慮兩項問題：第一，是載波間干擾有何特性，以及可如何抑制之？第二，是在引 導訊號稀少的情況下，如何作到夠好的時變通道響應估計與相應之訊號檢測？這兩者之 間何者較為重大，視系統參數(如子載波間距)及運作狀況(如移動速度)而定。針對第一 項問題，我們除延伸過去相關研究成果，探討點對點傳輸的載波間干擾特性與對策外， 並考量在多點共同對一點傳輸情況下，載波間干擾的特性與對策。此外亦探討其在先進 長程演進標準(LTE-A)規格下的應用。針對第二項問題，我們研究如何在引導訊號稀少 的情況下，以漸進的方式提升通道估計與訊號檢測的精確度，並探討其在載具環境無線 進接(WAVE)規格下的應用。

This project considers orthogonal frequency-division multiplexing (OFDM) signal reception technology for digital wireless communication under high-speed motion. We consider two problems. First, we consider the properties of intercarrier interference (ICI) and means to suppress it. And secondly, we consider how to achieve adequate time-varying channel response estimation and associated signal detection when pilot signals are sparse. Which of the two poses a greater issue depends on system parameters (such as subcarrier spacing) and operational conditions (such as motion speed). Concerning the first problem, besides extending our existing research results and investigating the characteristics of and countermeasures for ICI in point-to-point transmission, we also consider the characteristics of and countermeasures for ICI in cooperative multipoint-to-point transmission. In addition, we investigate the application of such under the LTE-Advanced (LTE-A) specifications. Concerning the second problem, we consider how to enhance the accuracy of channel estimation and signal detection in a progressive manner under the condition of sparse pilot signals. And we investigate the application of such under the Wireless Access in Vehicular Environments (WAVE) specifications.