在無線細胞系統中，同頻干擾效應對於系統效能來說是一個限制的因素，區域多點分配服務系統(Local Multipoint Distribution System, LMDS)，這種固定的無線傳輸系統也不例外。在LMDS中下鏈通常是較高容量的，而且較窄的用戶端天線的波束也是排拒同頻干擾(Co-channel interference)的一項因素。因此對LMDS中的下鏈方向同頻干擾的評估是本篇論文的主題。 為了有效降低LMDS中細胞間干擾的問題，在這篇論文中提出用戶端天線重新指派方向的觀念，利用此種方法可以獲得較少的細胞間干擾區間，進而增加系統的效能。 In wireless cellular systems, co-channel interference is the limiting factor to system performance. Fix wireless systems such as Local Multipoint Distribution Systems (LMDS) are no exception to this rule. Because the LMDS downlink is usually higher-capacity and beam-width of subscribers’ antenna is narrow beam width, therefore co-channel interference in downlink is more serious. This thesis proposes a concept of subscribers’ antenna reorientation to reduce this interference. Using this scheme, we can reduce the interfering regions and improve the system performance.
