下世代5G 行動通訊以服務現今日趨成長的智慧型手機用戶為主要對象,
更彈性、更有選擇性的開放式架構(Open Wireless Architecture) 是必然趨勢, 此外, 因其扮演了承先起後的角色, 首要方向是對現行行動通訊進行改善。在此論文, 焦點放於改善正交分頻多重存取(Orthogonal Frequency Division Multiple Access) 之不足。正交分頻多重存取使用正交分頻多工(Orthogonal Frequency-Division Multiplexing) 進行多載波傳輸, 當使用者位於細胞系統邊緣, 將遭受跨細胞干擾(Inter-Cell Interference) , 進而導致其訊號與雜訊干擾比(Signal-to-Interference Plus Noise Ratio) 降低,嚴重影響傳輸品質。基於以上考量, 我們使用時空編碼(Space-Time Cod-ing) 來賦予系統設計彈性, 權衡多天線多輸入多輸出(Multi-Input Multi-Output) 系統提供之各種增益, 並採用混合式蜂巢系統(Hybrid MultipleAccess Cellular System) , 使用多載波分碼多重接取(Multi-Carrier Code Division Multiple Access) 服務細胞邊緣使用者, 能有效抵抗跨細胞干擾,並增進整體系統效能。

In this paper, a space-time shift keying (STSK)-aided hybrid multiple access (HMA) system is proposed to attain a wide compatibility with the current and future generations of wireless communication systems. Specifically, the proposed HMA system comprises of the orthogonal frequency division multiple access-based (OFDMA-based) and multi-carrier code division multiple access (MC-CDMA)-based transmission techniques. In this fashion, both the main characteristics of OFDMA and MC-CDMA can all be inherited, i.e. high link capacity and interference tolerability. Moreover, to reach a better tradeoff between the antenna diversity and multiplexing gains, the STSK modulation is added on top of the OFDMA and MC-CDMA transmission schemes. Via this combination, a prototype of the so-called open wireless architecture platform can be constructed for developing the fifth generation mobile communication system. The advantages of the proposed hybrid system is proved by simulation results in terms of system capacity and outage probability.

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