室內無線通訊之波束合成技術於多用戶端之模擬研究

本論文在一個室內超寬頻系統環境下做兩種模擬，其一是發射端同時傳送相同訊號於群體廣播系統中，其二是發射端同時傳送不同訊號於多用戶多輸入多輸出的系統中；過程中，先將發射與接收天線做環型陣列的擺設，利用射線彈跳追蹤法計算出任意給定室內無線環境之脈衝響應，在發射端與接受端均使用波束合成的技術，使能量聚焦，減少通道之間的多路徑效應干擾。發射端和接收端同時利用自我適應之動態差異型演化法來調整天線的激發電流及饋入線長度，並以降低傳輸位元錯誤率作為目標函數，所搜尋到的天線輻射場型能滿足良好的通訊品質。根據室內超寬頻的環境裡，在兩組系統的模擬結果顯示，對於群體廣播系統中，在接收端使用波束合成的技術、提高演算法的搜尋粒子族群大小，與增加環型陣列裡的天線元件數目從8根提升為16根，能使發射與接收天線合成出更具指向性的輻射場型，降低位元錯誤率。對於多用戶多輸入多輸出的系統，利用自我適應之動態差異型演化法調整天線輻射場型，降低不同訊號間的干擾，將對應的訊號傳送給其對應的用戶。

關鍵字

超寬頻環型陣列天線；波束合成；自我適應之動態差異型演化法；多用戶多輸入多輸出；群體廣播

並列摘要

In this thesis, the Ultra Wideband Circle Antenna Array (UCAA) with beamforming techniques combining Self-Adaptive Dynamic Differential Evolution (SADDE) to minimize the multi-path effect of the channel and Bit Error Rate (BER) for Multicasting and Multi-user MIMO in indoor ultra-wideband (UWB) communication system is proposed. The UWB impulse responses of the indoor channel for any transmitter-receiver location are computed by SBR/Image techniques, inverse fast Fourier transform and Hermitian processing. By using the impulse response of multipath channel, the BER performance of binary pulse amplitude modulation (B-PAM) impulse radio (IR) UWB system with circular antenna array can be calculated. Based on the topography of the antenna and the BER formular, the array pattern synthesis problem can be reformulated into an optimization problem and solved by SADDE. The approach is not only choosing BER as the fitness function, but also practicely considering the excitation amplitude and feed length of each array element. Numerical results show that using beamforming techniques, changing the number of transmitter and receiver antennas from 8 to 16 and increasing SADDE particle size can be apparently synthesize the radiation pattern of the directional UCAA to reduce the BER for Multicasting and Multi-user MIMO.

並列關鍵字

UWB Circle Array Antenna ； Beamforming ； Self-Adative Dynamic Differential Evolution ； Muti-User MIMO ； Multicasting

參考文獻

[17] 賴智揚,“智慧型天線於寬頻分碼多重進接存取系統之應用,”中原大學電子系碩士論文, 2002.

[2] T. S. Rappaport, Wireless Communications, Prentice Hall PTR, 2002.

[4] H. Jeffrey and Reed, An Introduction to Ultra Wideband Communication Systems, Prentice Hall PTR, 2005.

[8] B.S. Paul and R. Bhattacharjee,“MIMO Channel Modeling : A Review,”IETE Technical, vol. 25, issue 6,Nov-Dec. 2008.

[10] W. M. Lovelace and J. K. Townsend,“The Effects of Timing Jitter and Tracking on the Performance of Impulse Radio,”IEEE Journal on Selected Areas in Communications, vol. 20, no. 9, pp. 1646-1651, December 2002.

國際替代計量

室內無線通訊之波束合成技術於多用戶端之模擬研究

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