本論文之研究目的，在於利用射線彈跳法去模擬，求得超頻寬通訊在不同人數分佈和六種不同環境材質的脈衝響應，這六種不同材質邊牆分別為：1.木板牆2.混擬土3. 夾板4.磚頭5.大理石6.鐵皮屋。透過這些多路徑通道的脈衝響應，使用二進制的脈波振幅調變(Binary Pulse Amplitude Modulation, BPAM)方法，進而計算超寬頻通訊系統的位元錯誤率(Bit Error Rate,BER)。我們可以從數值結果得知人數分佈與環境材質其多路徑對於通訊位元錯誤率性能的影響。 在本篇論文中所比較的通道特性參數，包含有均方根延遲擴散（RMS delay spread）、平均超額延遲擴散（mean excess delay spread）、最大的脈衝響應差值小於10dB的個數(NP10dB)與占總能量85%的脈衝個數(NP85)及位元錯誤率。由於無線電波在室內環境中容易受到遮蔽物的影響，這些遮蔽物例如:牆壁、天花板以及傢俱等，使得無線電波經由多重反射、繞射等路徑而到達接收天線，此一現象稱之為多路徑效應(multi-path effect)。由於此效應造成的符際間干擾(InterSymbol Inference,ISI)，使得通訊位元錯誤率及失效率(outage probability)增加，亦即通話品質變差。在這篇論文裡，我們將探討室內的人數分佈與環境材質在超寬頻通訊上對位元錯誤率的影響。最後，我們發現到目前這些模擬的情形不僅提供了比較的資訊，且更提供了性能減少這值得關注的訊息。 A comparison of UWB communication characteristics for different distribution of people and various materials of walls in real environments are investigated. The impulse responses of these cases are computed by applying shooting and bouncing ray/image (SBR/Image) techniques and inverse Fourier transform. The frequency dependence utilized in the structure on the indoor channel is accounted for in the channel calculation. By using the impulse response of these multi-path channels, the mean excess delay, root mean square (RMS) delay spread, and the number of multi-path arrivals within 10 dB of the peak multi-path arrival (NP10dB), and the number of paths required to meet the 85% energy capture threshold (NP(85%)) for these different distribution of people and various materials of walls have been obtained. The bit error rate (BER) performance for UWB indoor communication is calculated. The outage probability for binary antipodal-pulse amplitude modulation (B-PAM) system has been presented. Numerical results have shown that the multi-path effect by people is an important factor for BER performance. Finally, it is worth noting that in these cases the present work provides not only comparative information but also quantitative information on the performance reduction.
