在各項微波傳輸技術中，LMDS可以說是相當受到注目的。因為它可以提供雙向的語音、影像及數據傳輸的寬頻整合服務。LMDS能夠滿足各類型的用戶分佈與應用，從住家到商業用途均能提供服務，因此更具有彈性及擴充性。台灣在2000年發放固網執照，即使有線寬頻傳輸應是其競爭的主軸，然而仍有業者藉助固定無線傳輸技術的應用，以提高其競爭力。由此可窺知LMDS的發展潛力。 為了有效降低LMDS中細胞間干擾的問題，本論文提出新的細胞規劃，可以獲得較少的細胞間干擾。然後討論和比較加上干擾碼與未加干擾碼的不同。並分析分碼多重擷取加上功率控制的技術，以減少受到的干擾。接著討論動態調變在LMDS環境的影響，我們可以使用較高階的調變器在通道品質較好的時候來增加系統可負載的資料速率。 LMDS is the most obtrusive among mini-meter wave propagation techniques. Because it can provide wideband integrated services including two-way voice, video, and data transmission. The asymmetry between downstream and upstream is quite consistent with the normal data flow, particularly for residential applications. In this article, we first analyze interference in O-CDMA system. The performance of system with and without scrambling code will be compared. Of course, the technique of power control will be applied to reduce inter-cell interference effect. Besides, high rainfall attenuation is a significant challenges associated with deploying systems at Ka band. And with dynamic modulation scheme, we can choose the mode to be modulated according to channel situation.
