| 摘要: | 多輸入多輸非正交多重接取(Multiple-Input Multiple-Output Non-orthogonal multiple access, MIMO-NOMA)系統中，在接收端有嚴重的干擾問題，造成訊號無法順利解出，因此如何抑制干擾是個必須面對的議題。過去幾年，已經有很多技術被提出來解決此問題，其中利用傳送端預編碼(Precoding) 是常被拿來使用的技術之一，然而再傳送訊號前基地台(Base Station,BS) 必須先了解全局的通道狀態資訊(Channel State Information,CSI)，在實際傳輸上面臨重大挑戰，再者此方法並無法將所有使用者干擾完全消除乾淨，且在接收天線數也有所限制，因而降低整體系統效能表現。
本論文，我們提出MIMO檢測(Detection) 技術，透過使用者在接收端自行將干擾消除，不但不須回傳全局CSI，更能完全消除干擾，在接收天線數目上也有調整彈性。因此，首先我們提出三種分別 Zero-forcing、MMSE及SVD檢測方法，並設計了一個基於QR 分解檢測之MIMO-NOMA系統，對其進行中斷機率數學分析，最後利用模擬與數學推導結果進行比對，且比較各方法之性能及優缺點。;In a multiple-input multiple-output non-orthogonal multiple access (MIMO-NOMA) system, serious interference occurs at the receiver, leading to the received signal unable to be successfully decoded. In the past few years, many methods were proposed to solve this problem. Transmitter precoding is one of the widely used techniques. However, the base station (BS) must acquire the global Channel State Information (CSI) before transmission, and thus the system overhead is increased. Moreover, Precoding techniques cannot effectively eliminate inter-cluster interference as well as limit the number of receiving antennas. Due to the above disadvantage, the overall system performance is seriously degraded.
In this thesis, we propose a MIMO detection technology which can let the user eliminate interference by itself. This method not only does not need to return the global CSI, but also can completely eliminate interference. Moreover, it has the flexibility to adjust the number of receiving antennas. First, we study three different detection methods, i.e., Zero-forcing, MMSE, and SVD, and then propose a QRD-Based Signal Detection method for the MIMO-NOMA system. The mathematical analysis of outage probability is explored and the computer simulation is
performed to compare the performance for different detection methods. |
