透過您的圖書館登入
IP:3.143.168.172
  • 學位論文

利用APSO超寬頻陣列天線尋找多目標

Multi-Objective Optimization for UWB Antenna Array by APSO Algorithm

指導教授 : 丘建青

摘要


近年來由於超寬頻通信系統的短距離、低功率之寬頻傳輸特性使其成為目前室內通訊新技術。已有許多超寬頻通訊在室內傳輸的相關文獻已經被發表,大多研究是以模擬或量測方式找出影響通道的統計參數後,並分析在此通道統計模型下的系統傳輸錯誤率及通道容量。本研究的目標是希望利用天線場型的調整,使得系統傳輸位元錯誤率能夠降至最低以及提升通道容量和最大化接收端能量,達到多目標最佳化場型。其中的要件除了通訊系統的參數之外,還包括室內環境多路徑傳輸效應的影響,因此要解決這樣的問題可以看成一種求解多目標最佳化的問題 由於APSO的好處在於不須列出變數和因變數的明顯數學關係亦能找出最佳解,因此本研究使用APSO作為最佳化的工具。和一般以天線場型為目標函數所不同的地方是,本研究擬以降低室內通信傳輸位元錯誤率加上通道容量以及接收端能量為多目標函數,再利用APSO作最佳化的 調整,尋找出多目標最佳化天線場型,此種場型最能滿足室內無線通訊的需求。 模擬數據顯示,透過APSO分別地調整環型陣列天線中每一個天線元件的信號饋入線長度,且能在3GHz-7GHz 合成具有指向性的天線輻射場型。指向性輻射場型能提供以下優點。(1) 在接收端能有效地接收到每根天線所幅射出的能量,並進而提高接收端的訊雜比。(2) 此指向性輻射場型能有效地減少多路徑效應的發生,使得接收信號能量有效 提升。 (3) 可大幅降低位元錯誤率及提升通道容量,提高通訊品質。

並列摘要


In this thesis, a uniform circular antenna array (UCAA) combining genetic algorithm (GA) and asynchronous particle swarm optimization (APSO) for finding out global maximum of multi-objective function in indoor ultra-wideband (UWB) communication system is proposed. The algorithm is used to synthesize the radiation pattern of the directional UCAA to reduce the bit error rate (BER), to increase channel capacity(CC), and received energy (RE) in indoor UWB communication system.Using the impulse response of multipath channel, the BER of the synthesized antenna pattern on binary antipodal-pulse amplitude modulation (B-PAM) system can be calculated. Based on topography of the antenna and the shooting and bouncing ray / image (SBR/image) techniques, the synthesized problem can be reformulated into a multi-objective optimization problem is employed and solved by the GA and APSO. Numerical results show that the fitness value and convergence speed by APSO is better than by GA.

參考文獻


[21] Chien-Hung Chen and Chien-Ching Chiu and Ching-Yun Wu and Shu-Han Liao"A multi-objective optimization for UWB antenna array in indoor environment," Intelligent Signal Processing and Communications Systems (ISPACS), 2013 International Symposium, Nov. 2013,pp. 565 – 568.
[27] S. H. Chen and S. K. Jeng, “An SBR/Image approach for indoor radio propagation in a corridor,” IEICE Trans. Electron., Vol. E78-C, Aug. 1995, pp. 1058-1062.
[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.
[6] J. Jerabek, L. Zaplatilek and M. Pola, “A proposal of radio ultrawideband systems for precision indoor localization,” Radioelektronika (RADIOELEKTRONIKA), 2015 25th International Conference, 21-22 April 2015, pp.355,358.

延伸閱讀