應用於多輸入多輸出無線通訊之高效率瑞立衰減通道模擬器

Abstract

在多輸入多輸出衰減通道中，其子通道具相關性，這成為多天線系統及空間-時間技術中效能估算的主要關鍵。在分析通訊系統中，一般都將通道假設為廣義平穩非相關散射通道。基於廣義平穩非相關散射通道所設計之通道衰減模擬器，一般而言具有高準確性。此外，因通道是操作在高取樣頻率下，若欲實現一個即時的通道模擬器則通道衰減模擬器應具有低計算複雜量；因此，如何實現一個正確且快速的模擬器成為一個重點的議題。在本論文中，吾人使用KL展開法提出一個高效率的衰減通道模擬器。比起既有使用弦波疊加的方法，此模擬器可有效增進通道統計特性的正確性且需要較低的計算複雜量。最後，從模擬的結果証實吾人所提出的衰減通道模擬器符合即時多輸入多輸出通道的需求。

Simulation of multiple-input multiple-output (MIMO) fading channels, with correlated subchannels is the key to performance evaluation of space-time techniques in multi-antenna systems. Wide sense stationary uncorrelated scattering (WSS-US) channels are assumed for the analysis of communication system. The fader is typically designed under the assumption of WSSUS channels, which is shown to exhibit high accuracy. Furthermore, since the channel is operated at a high sampling rate, low computational complexity is essential if a real-time channel simulator is desired. Therefore, how to realize an accurate and fast channel model becomes an important issue. In this thesis, we propose an efficient fading channel simulator by using the K-L expansion method. It can improve the accuracy of the statistical properties of the model and requires lower computational complexity than traditional models using sum-of-sinusoids. Finally, simulation results suggest that the proposed fading channel simulator meets the demand of real-time MIMO channel.