| DC 欄位 |
值 |
語言 |
| DC.contributor | 通訊工程學系 | zh_TW |
| DC.creator | 廖健宏 | zh_TW |
| DC.creator | Chien-Hung Liao | en_US |
| dc.date.accessioned | 2006-7-3T07:39:07Z | |
| dc.date.available | 2006-7-3T07:39:07Z | |
| dc.date.issued | 2006 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:444/thesis/view_etd.asp?URN=93523023 | |
| dc.contributor.department | 通訊工程學系 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 由於LMDS乃是使用28GHz之雙向數位式細胞系統，同頻干擾(Co-channel Interference) 對於系統性能是一個限制因素，尤其LMDS的下傳鏈路(Downstream)通常有較高的容量，因此在下傳鏈路的同頻干擾比上傳鏈路(Upstream)嚴重。正交分頻多工(Orthogonal Frequency Division Multiplexing; OFDM)是一套有效率的方法，可以傳輸高速率資料及對抗碼際干擾(Inter-symbol Interference)和多路徑傳輸的衰減。本論文主要是探討如何提昇以OFDM為基礎之區域多點分配服務系統的性能，我們將模擬LMDS的寬頻通道、架構OFDM傳輸系統，利用多重輸入多重輸出(Multi-Input-Multi-Output; MIMO)架構來估測用戶端(Subscriber)與基地台(Base station) 與細胞間干擾之干擾台(Interfering Stations)之通道頻率響應，並
以估測的通道頻率響應來實現通道等化(Channel Equalization)。如此一來，細胞間的干擾可以有效地降低。本論文也會討論利用調適性調變(Adaptive modulation)技術，以提昇系統的效能。 | zh_TW |
| dc.description.abstract | LMDS usually operates at millimeter-wave frequencies about 28 GHz and it is a two-way digital cellular system, co-channel interference is the limiting factor of system performance. In the downstream, the channel capacity is higher than that in the upstream, and the co-channel interference of the downstream is more serious than that of the upstream. In order to reduce the co-channel interference, we apply the orthogonal frequency division multiplexing (OFDM) to the LMDS system to simulate the OFDM-Based LMDS. OFDM is an efficient and suitable technique to combat ISI in wideband channels. Since each OFDM sub-carriers has a very narrow spectrum. It can transmit high data rate and combat the inter-symbol interference and the multipath fading. In this thesis, we will improve the performance of OFDM-Based LMDS system by using MIMO structured channel estimation. In order to promote systematic efficiency, this thesis will adopt adaptive modulation techniques too. | en_US |
| DC.subject | 區域多點分配服務 | zh_TW |
| DC.subject | 多重輸入多重輸出 | zh_TW |
| DC.subject | 正交分頻多工 | zh_TW |
| DC.subject | OFDM | en_US |
| DC.subject | LMDS | en_US |
| DC.subject | MIMO | en_US |
| DC.title | 使用MIMO架構的通道估測來降低OFDM架構下LMDS系統的同頻干擾 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.title | Reducing the Co-channel Interference of OFDM-based LMDS Systems by MIMO Structured Channel Estimation | en_US |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |