基於IDMA之eMBB與URLLC疊加系統之干擾壓抑

Abstract

在最近幾年，第五代行動通訊系統廣泛地被大家討論，其中增強型行動寬頻 (enhanced mobile broadband, eMBB)與高可靠低延遲通訊(ultra-reliable low latency communications, URLLC)為兩項重要的應用。在本論文中，我們提出了利用分交錯器多從存取(interleave division multiple access， IDMA)技術當作eMBB傳送的調變方式，並開發了一個eMBB與URLLC的疊加傳輸方案。當eMBB與URLLC疊加傳送時，由於URLLC的訊號功率比eMBB的訊號功率大上許多，所以eMBB的訊號會受到嚴重的干擾。為了改善此問題，我們在IDMA系統接收端的解碼演算法進行修改，並改變了IDMA系統上的QAM重複倍數。模擬結果顯示，我們所提出的系統能有效地降低干擾問題，且能藉由調整QAM的重複倍數彈性地調整冗餘訊息量(redundancy)以達到不同系統需求。

In recent years, fifth-generation (5G) mobile communication is widely discussed, in which enhanced mobile broadband (eMBB) and ultra-reliable low latency communication (URLLC) have been proposed as two important application scenarios. In the thesis, we propose using interleave-division-multiple-access (IDMA) for eMBB modulation, and develop a superposition transmission scheme for eMBB and URLLC. Superposition transmission will cause serious interference for eMBB signal since the power of URLLC signal is usually much larger than that of eMBB. To solve the problem, we modify the decoding algorithm at the IDMA receiver, and vary the number of QAM level code repetition in IDMA. Simulations show that the proposed scheme can effectively mitigate the interference problem and the redundancy introduced by QAM level repetition coding can be flexibly controlled to meet different system requirements.