臺灣博碩士論文加值系統

進年來由於WIMAX和LTE系統作為近4G之行動電話系統之準候選，在2G/3G行動網路密度近於飽和之下，採用中繼跳躍來改善通話品質和降低網路新增基地台數，已為不可抵擋之趨勢。本文主要分析傳送端及接收端通道因地形遮蔽或電波無法直接傳送抵達，必須將訊號藉由中繼站來進行轉傳至接收端。在傳送訊號源採用Alamouti[1]之時空編碼（Space-Time Block Coding ;STBC），分析比較使用一個中繼站( single hop )及兩個中繼站( multi-cell relay hopping(N=2))分別在中繼端接收後先解碼再傳送至接收端( Decode-and-Forward ; DF )和中繼端接收不解碼直接傳送至接收端(Amplify-and-Forward ; AF)電腦模擬用於分析以上四種中繼網路模式分別針對其多種組合模式錯誤率(Bit Error Rate ; BER)，依據以上分析結果，本論文最後提出建議模式以提供系統建置之參考。

Relay hopping and cooperation mechanism has been evaluated based on single hop and multi-hop( two-relay station ) incorporated with multi-cell collaboration( i.e. multi-cell relay hop ).This study was performed using space-time block-code with relay-decoded hopping ( non-transparent relays ) and relay amplify-and-forward ( transparent relay ) model using MISO 2-by-1 antenna structure respectively. At the end, the Bit-Error-Rate and bandwidth efficiency were presented based on the system simulation, in comparison of multi-cell two relay and one relay models.
Simulation results indicated that the multi-cell two relay model is superior to one relay model, and the transparent relay (without pre-decoding) is better than the pre-decoded relay hopping. That is the pre-decoded hop which causes the accumulated symbol error when the channel form BTS to relay station is in deep fading . During our study, it is assumed that the channel estimation is perfect over independently and individually distributed multipath fading channel.

第一章 緒論…………………………………………………….1
1-1 研究動機 …………………………………………..1
1-2 研究目的………………………………………………2
1-3 研究方法………………………………………………2
第二章 Relay-Hopping與時空區塊編碼之介紹………………4
2-1 Relay-Hopping簡介……………………………….4
2-2 Relay-Hopping之應用…………….….………….6
2-2.1 再生的解碼以及發送………………………………6
2-2.2 非再生的解碼以及發送……………………………6
2-2.3 放大以及發送………………………………………7
2-2.4 壓縮以及發送………………………………………7
2-3 分集……………………………………………………7
2-3.1 空間分集…………………………………….....8
2-3.2 頻率分集…………………………………………..8
2-3.3 時間分集……………………………………………8
2-4 時空區段碼系統模型…………………………………9
2-4.1 時空區段之阿摩(Alamouti)編碼…………....9
2-4.2 MISO天線架構之時空碼………………………..10
第三章 中繼跳躍系統設計之演算方法…………………………12
3-1 中繼跳躍系統簡介………………………………….12
3-2 中繼跳躍系統演算方法………………….………..13
3-2.1 Amplify-and-Forward(AF)中繼跳躍(single hop)模型之
數學式建立…………………................13
3-2.2 Decode-and-Forward(DF)中繼跳躍(single hop)模型之
數學式建立…………………………………………17
3-2.3 Amplify-and-Forward(AF)中繼跳躍(Multi-cell relay
hopping(N=2))模型之數學式建立………....20
3-2.4 Decode-and-Forward(DF)中繼跳躍(Multi-cell relay
hopping(N=2)模型之數學式建立……………..26
3-3 頻譜效益分析………………………………………32
第四章 系統模擬………………………………………………………34
4-1 通道參數設定……………………………………………34
4-2 錯誤率及頻譜效益分析…………………………………36
第五章 結論…………………………………………………………..42
參考文獻……………………………………………………………...43

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