本篇論文於受有窄頻干擾(Narrowband Interference)與多重接取干擾(Multiple Access Interference)下的超寬頻(Ultra-Wideband)無線通訊系統中，提出一個以串接(Cascade)結構或以聯合(Joint)結構之基於最大訊號雜訊比例(Maximum Signal to Interference-plus-noise Ratio)之空時選擇性犁耙接收機(Space-time Selective RAKE Receiver)。為能在低複雜度下有效地抽取有興趣的訊號，我們連同所提出的空時選擇性犁耙接收機，另外提出兩個路徑安排策略(Finger Assignment Strategies, FASs)，其分別為基於能量之路徑安排策略(Energy-based FAS)與有限制的基於能量之路徑安排策略(Constrained Energy-based FAS)。藉由電腦模擬結果，我們顯示所提出的基於最大訊號雜訊比例之空時選擇性犁耙接收機相較於現存的時間選擇性犁耙接收機(Time-only Selective RAKE Receivers)以及基於最大比例結合(Maximum Ratio Combining)之空時選擇性犁耙接收機，在皆使用基於能量之路徑安排策略下，更能夠提供較大的系統容量(System Capacity)並且有較佳的抵抗窄頻干擾能力。另一方面，透過分析與模擬結果，我們證明所提出的空時選擇性犁耙接收機在使用基於能量之路徑安排策略時，其性能表現易受窄頻干擾之影響，且若有較強的窄頻干擾出現於接收端時，其性能表現將顯著地降低。相反地，使用有限制的基於能量之路徑安排策略的空時選擇性犁耙接收機，其對於窄頻干擾仍有非常穩健的性能表現，而且當窄頻干擾為系統的主要干擾來源時，我們所提出的接收機在使用有限制的基於能量之路徑安排策略下的性能將遠優於使用基於能量之路徑安排策略下的性能。

This thesis proposes a space-time selective RAKE (SRAKE) receiver (in cascade form and in joint form) by maximizing signal to interference-plus-noise ratio (MSINR) for ultra-wideband (UWB) wireless communications in the presence of narrowband interference (NBI) and multiple access interference. For effectively extracting the UWB signal of interest with low complexity, two finger assignment strategies (FASs), the energy-based FAS (EB-FAS) and the constrained energy-based FAS (CEB-FAS), are also proposed together with the proposed space-time MSINR-SRAKE receiver. By some simulation results, we show that the proposed space-time MSINR-SRAKE receiver can provide larger system capacity and better immunity to the strong NBI than the existing time-only SRAKE receivers and space-time SRAKE receivers with maximum ratio combining (MRC) when the EB-FAS is used. On the other hand, through analyses and simulation, we demonstrate that the space-time MSINR-SRAKE receiver using the EB-FAS is susceptible to the impact of NBI, and the receiver performance is severely degraded when a strong NBI is present. On the contrary, the space-time MSINR-SRAKE receiver using the proposed novel CEB-FAS outperforms that using the EB-FAS when NBI is the dominant interference, and is much robust against NBI.

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