正交分頻多工系統之多符元通道估測方法

Method of multisymbol channel estimation for OFDM system

顏廷儒(Ting-Ju Yen)

指導教授 ： 魏學文

共同指導教授 ： 詹益鎬

國立暨南國際大學/科技學院/電機工程學系/碩士(2010年)

https://doi.org/10.6837/NCNU.2010.00101

摘要

在高速時變通道環境下，需要時變的通道估測才能滿足性能需求，本論文提出多符元時變通道估測法，其概念是將多個符元作為一個觀察窗口，並且每個符元中僅需插入少數導引信號(Pilots)，利用接收到的導引信號結合時變通道曲線估測法(Curve-fitting method)以求出通道變化曲線之係數，進而計算觀察窗口內之所有符元通道響應；並且以多符元時變通道曲線估測法為基礎，只選擇取用中間符元範圍之估測效能，發現調整後之方法能更有效提升效能，稱之為多符元時變通道估測法-改良型。本方法在極高的正規化都卜勒頻率( )下，並在低導引信號負載 (Overhead)下也可獲得不錯的通道估測效能。在與對稱式雙訓練符元時變通道曲線估測法做運算複雜度比較，可發現在低導引信號負載的情況下，能達成高度簡化的目標。

關鍵字

正交分頻多工 ； 通道估測 ； 時變通道 ； 導引信號 ； 導引信號負載

並列摘要

This research presents a multisymbol channel estimation for orthogonal frequency division multiplexing (OFDM) systems. This method particularly works well in fast time-varying fading channels. The method regards a successive multisymbol as an observation window, i.e., expanding the time scale of the observation. Each symbol inserts numbered pilots. Each window estimates channels by way of pilot reception and polynomial function approximation. For each window, a set of polynomial coefficients can be obtained to represent the channel. And I propose a multisymbol channel estimation as a basis, but only access to the middle symbol estimation results, called “multisymbol channel estimation - Improvement Type”. The accurate estimation results show that our invention is better than some existed methods in high normalized Doppler frequency ( fdT ); meanwhile the performances are well for low overheads.

並列關鍵字

OFDM ； Channel estimation ； Time varying channel ； Pilot ； Overhead

參考文獻

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