量化MIMO系統通道容量之研究與分析

Abstract

多重輸入多重輸出(MIMO)系統在過去數年,已被證實擁有許多好處,其中最主要的好處為增加頻寬效益(spatial multiplexing)和對抗通道衰減(spatial diversity),但過去對於MIMO系統的研究， 甚少考慮接收端量化的問題,在實際的應用上,發射及接收的信號都是離散訊號。在這篇論文中,我們主要研究接收訊號經過量化後,MIMO系統的通道容量，並且考慮簡單的Relay Channels。 我們首先提出在傳送訊號有功率限制的情況下，且接收訊號經過量化的通道容量計算演算法,並且經由分析其最佳輸入信號的機率分布,說明且驗證演算法的正確性,接著用我們所提出的演算法模擬在不同的MIMO架構中所得到的通道容量且說明其結果,並且在傳送天線數以及調變信號固定的情況下,討論AGC 使其可以得到最大的消息量。最後,我們分析簡單的relay channel經過量化後的通道容量。

In the past few years, MIMO systems were already proven to have many advantages. The main advantages are spatial multiplexing and spatial diversity. In the past research, few have considered the problem of discrete signals at the transmitters and receivers; in this thesis, we study and analyze the capacity of quantized MIMO systems and consider the case of simple relays. We propose an algorithm that can calculate Discrete-input and Quantized-output channel capacity with input power constraint and analyze the optimal input distribution. Then we run the algorithm to calculate channel capacity of different MIMO scenarios and explain the simulation results. Proper AGC scheme is also used to get the maximum information rate. Finally we consider simple relay channels and the simulated channel capacity is presented.