室內向量寬頻通道模型及其在無線區域網路及多天線系統的應用

Vector Wideband Indoor Channel Modeling and its Applications to WLAN and Multiple Antenna Elements Systems

游宗樺(Zong-Hua You)

指導教授 ： 李學智

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.01042

摘要

在本論文，我們提出了一個可應用於多天線系統的室內向量寬頻通道模型。本通道模型是根據Saleh-Valenzuela的通道模型而來並且由 、 及 這三個參數來描述。 是直接波與線性廻歸線(斜率為 )截點的差值、 為線性廻歸線的斜率、 為射線的平均抵達頻率。我們同時提出並驗證一個萃取這些通道參數的方法。然後我們利用此一通道模型來探討當多天線系統使用切換式波束形成(switch beamforming)或空間多工 (spatial multiplexing) 技術時，對於不同的通道參數所表現出的通道特性及傳輸效能。
　　切換式波束形成技術可以降低最小所需的訊號雜訊比(minimum required SNR)，即使直接波被完全阻擋。我們發現當 越大、線性廻歸線的斜率越陡或射線的平均抵達頻率越小時，最小所需的訊號雜訊比將越小。然而，使用空間多工技術則會有相反的結果－環境的多路徑波成份越多，所需的訊號雜訊比越小。此外，當環境的多路徑波成份貧乏時，使用空間多工技術系統的傳輸效能可能會比單一輸出單一輸入(SISO)的系統差。

關鍵字

室內通道模型 ； 多輸入多輪出 ； 波束型成 ； 空間多工

並列摘要

In this thesis we propose a vector wideband indoor channel model which can be employed by systems with closely spaced multiple antenna elements. This channel model is based on the single cluster Saleh-Valenzuela (S-V) model and described by the parameter set { , , } which are respectively the amplitude difference of the direct path and the start point of the multipath regression line, the slope of the regression line, and the mean arrival rate. The procedure to extract the channel parameters is also proposed and verified. Then, we use this channel model to discuss the channel characteristics and transmission performance of multi-antenna systems employing switch beamforming or spatial multiplexing for different channel parameters.
The switch beamforming technique can reduce the minimum required signal to noise ratio (SNR) even though the direct path is almost blocked. We found that the minimum required SNR is smaller when the is getting greater, the slope of the regression line is getting larger, and the mean arrival rate is getting smaller. However, the spatial multiplexing technique has the opposite result, i.e. the richer the multipath components, the smaller the SNR. In addition, when the environment has poor multipath components, the transmission performance of systems employing spatial multiplexing may be worse than that of single-input single-output (SISO) systems.

並列關鍵字

indoor channel model ； MIMO ； beamforming ； spatial multiplexing

參考文獻

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