目前的跳碼多工系統的發展，是改良一維碼的分碼多工系統，使之可以提供更多的用戶容量，但是一維碼僅在用戶間同步且沒有多路徑通道的理想環境下有正交性，因此發展性受到極大的限制。
在這份論文中，將利用正交互補碼在用戶間非同步以及有多路徑通道中仍然擁有完美的正交性質，提出正交互補碼的跳碼多工系統。
我們會介紹系統架構並且針對各種環境來作理論分析，再使用程式模擬來驗證。最後我們發現使用正交互補碼的跳碼多工系統在用戶間非同步的上行環境中，可以提供比用戶間同步的下行環境更多的用戶容量。

Compared with traditional CDMA system which uses one-dimensional code, the current code hopping multiple access system can provide more user capacity by combining code-hopping mechanism with traditional CDMA technology. However, the orthogonality in a traditional CDMA system can only be preserved under the condition that users are synchronous and there is no multi-path interference (MI).
In other words, the development of current code hopping multiple access system is confined by its bad performance in a non-ideal channel.
In my thesis, we utilize orthogonal complementary code, which preserve perfect orthogonality in an asynchronous and MAI channel, to implement code hopping multiple access system.
First, we will introduce the system model and its theoretical analysis in all kinds of channel condition; then, we continue to verify the analytic result using numerical computing software. According to the simulation result, we find that more user capacity can be supported by the orthogonal complementary code hopping multiple access system in the asynchronous uplink scenario if compared with synchronous downlink scenario.

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