第四代行動通訊技術，將基於正交分頻多工系統在多輸入多輸出環境工作之研究中。本計畫執行時間上，正值4G 技術蓬勃發展的時刻。本計畫將要研發正交分頻多工系統中的幾項核心技術，例如: 正交分頻多工系統之頻率漂移補償技術，子載波擷取技術與通道檢估技術；尤其著重於最小平方差通道檢估技術用於高速移動環境之正交分頻多工行動通訊系統、用於快速時變且頻選式衰落環境之正交分頻多工行動通訊系統中聯合盲蔽式最大概率時序與頻率漂移估計器與基於擬似亂碼之正交分頻多工系統。以上各項研究均基於前幾年計畫有部分研究成果，試圖在本計畫作更深入、更完整與更務實的研究。 ; OFDM technologies have focused a lot of research efforts in academia and received substantial research and development attentions in industry because they are expected to be the core technologies in the 4G standards of mobile communication in the near future. In this project, the core and essential transceiving technologies and techniques, such as time-synchronization in OFDM, frequency offset estimation/compensation in OFDM, channel estimation and equalization in OFDM will be deeply and thoroughly investigated here. It should be emphasized that this project will focus on least-squares channel estimation with assistance from linearly frequency-modulated (LFM) signals, joint blind maximum-likelihood estimation (MLE) of time and frequency offset in mobile OFDM on a time-varying frequency-selective fading channel, and channel estimation, frequency offset and timing synchronization technologies for pseudo-random-postfixed OFDM communications. Some of the aforementioned technologies have been studied in our preceding NSC research projects, and some preliminary results have been published previously. However, these important and essential techniques are worthwhile conducting deeper and more thorough research both in theory and in practice. ; 研究期間 9808 ~ 9907
