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    題名: Channel characteristics and modeling for wireless communication system
    其他題名: 無線通信系統之通道特性與模型研究
    作者: 陳建宏;Chen, Chien-hung
    貢獻者: 淡江大學電機工程學系博士班
    丘建青;Chiu, Chien-ching
    關鍵詞: 位元錯誤率;多重路徑;路徑損失;超寬頻;彈跳式射線追蹤法;BER;multipath;path loss;UWB;SBR/Image
    日期: 2006
    上傳時間: 2010-01-11 07:08:03 (UTC+8)
    摘要: 本論文最主要的目的在於無線通信通道的研究並提出高速個人通訊服務在多重路徑環境下的位元錯誤率分析。本論文內容分為三部份。第一部份,提出一種新的室內路徑損失的預測模型。第二部份,為高速個人通訊服務在各種不同類型之多重路徑環境下的位元錯誤率分析。第三部份,為室內超寬頻通信環境之通道脈衝響應的計算。
    在辦公室的環境下,對於有金屬傢俱的小房間環境提出一種新的預測模型。該模型同時考慮空間傳播損失與物體繞射損失的現象。只要根據環境的佈局方式就可以預測出接收功率的大小。該模型的優點在於使用較少的運算量就可以得到精確的結果。不像射線追蹤法那樣追蹤每一個路徑需要大的運算量。
    然而,所有的無線通信系統都必需考慮在有多重電波反射、繞射與散射現象環境下的多重路徑傳播通道的影響。為了瞭解各種不同類型的無線電波傳播與通道特性的影響,例如辦公室、不同形狀的建築物以及隧道等等,本論文提出高速個人通訊服務在這些環境下的位元錯誤率分析。數值結果顯示,多重路徑效應的影響是造成環境通訊不良的主要因素。並且使用扇形天線、分集技術以及決策回授等化器等技術能夠有效地抑制室內環境的多重路徑效應,改善通訊品質以及增進位元傳輸速率。
    最後,本論文提出以彈跳性射線追蹤法與反傅立葉轉換的方法來計算室內超寬頻通信環境的通道脈衝響應。通道脈衝響應的計算有考慮到物體材質在不同頻率下的影響。根據這些超寬頻通道脈衝響應的計算,可以得知在室內環境下金屬櫃對於多重路徑傳播的影響。
    The main purpose of this thesis is to research on channel characteristics for wireless communications and present the bit error rate (BER) performance analysis for high-speed personal communication service in multipath environment. This thesis has three parts. The first part, a new indoor path loss prediction model is proposed. The second part, the BER performance analysis for high-speed personal communication service in different multipath environments is investigated. The third part is the impulse responses calculation for ultra-wide band (UWB) indoor communication.
    In office environment, a novel prediction model for small rooms with metallic furniture is proposed. Both the propagation loss and the diffraction loss have been considered in this model. The receiver power prediction from the transmitter to the receiver antenna is predicted based on the layout of the environment. The advantages of this model are less computational load and high accuracy. It is not necessary to trace every path compared with the ray-tracing technique.
    However, all wireless systems must be able to deal with the challenges of operating over a multipath propagation channel, where objects in the environment can cause multiple reflections, diffraction, and scattering to arrive at the receiver. To understand the radio propagation and channel characteristics for different multipath environments, such as office, buildings, and tunnels, the BER performance analysis for high-speed personal communication service are investigated. Numerical results have shown that the multipath effect is an important factor in an adverse communication environment and using sectored antenna, diversity techniques and decision feedback equalizer can efficiently reduce multipath effect, improve the quality of communication and increase the bit transmission rate in indoor environments.
    Finally, a method for calculating the channel of UWB indoor communication systems has been presented by SBR/Image techniques and inverse Fourier transform. The frequency dependence of materials utilized in the structure on the indoor channel is accounted for in the channel simulations. By using the impulse responses of the multi-path channels, the impact of metallic cabinet to indoor multi-path is presented.
    顯示於類別:[電機工程學系暨研究所] 學位論文

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