第三代行動通訊WCDMA-FDD模式軟式交遞網路同步實驗

WCDMA-FDD 使用細胞間非同步運作，其目的是避免使用以全球位系統(Global Positioning System，GPS)為同步的信號來源，並且克服了必須提供建築物內較小型基地台額外同步來源的困難。因為非同步的技術不需要外來的時間基準來源，使得系統可以彈性的從室外佈署到室內，但這卻使基地台的搜尋與展頻碼的同步變的較複雜。根據實際的例子，WCDMA-FDD的基地台服務品質(Quality of Service，QoS)與同步的良窳似有相當的關連性，本論文就是針對此關連性，藉由實驗作一探討。本文主要研究內容為：以儀表配合實驗環境進行WCDMA-FDD手機進行軟式交遞(soft handover)模擬，在軟式交遞過程中，變更WCDMA-FDD基地台的參考頻率的準確度與穩定度，觀測其QoS是否受其影響，並列出實務上可能遇到與此有關的問題及解決方案。

關鍵字

第三代行動通訊；軟式交遞；網路同步；準確度；穩定度

並列摘要

WCDMA-FDD (Wide Band Code Division Multiple Access-Frequency Division Duplex) belongs to asynchronous operation. By adopting an asynchronous approach, it could overcome some of deployment challenges such as in–building deployment or dense urban areas which is difficult to get reference clock. Besides, it also doesn’t need extra timing source. But WCDMA-FDD asynchronous operation makes cell search and spread spectrum codes more complex. According to real cases there are some relationships between the performance and the frequency offset of the WCDMA-FDD Node Bs. The aim of the experiments is to investigate the impact of frequency offset and frequency stability between two WCDMA FDD Node Bs on the quality of service (QoS), as perceived by the user, when soft handover occurs. The major content of this thesis is to perform the synchronization experiment using the emulated WCDMA soft handoff environment based on the instruments. The accuracy and stability of the reference frequency in the Node B of WCDMA are adjusted to observe the effect on the QoS during soft handover.

並列關鍵字

WCDMA-FDD ； soft handover ； network synchronization ； accuracy ； stability

參考文獻

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國際替代計量

第三代行動通訊WCDMA-FDD模式軟式交遞網路同步實驗

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