利用非線性演算法於直接序列展頻通訊之窄頻干擾消除

Abstract

展頻系統的主要優點是擁有消除窄頻干擾的能力，這些干擾是來自刻意的 或是他人使用同一 頻帶。若將收到的訊號在沒經過擬亂數 ( PN ) 正前 先經過濾，則可大大地增加直接序列( DS 擾能力，本論文提出多種的非 線性演算法以消除窄頻干擾，包括非線性最小均方差 (LMS) 法、非線性 遞迴最小平方 ( RLS ) 法、和非線性卡門 ( Kalman C經由電腦模擬 顯示，設計出來的非線性演算法比傳統的方法更優越。 The primary advantage provided by spread spectrum systems is the ability to reject narrowband interference due to jamming or users during the recovery of the desired signal. It is known that the narrow-band interference rejection capability of a direct-sequence (DS) spread-spectrum system can be enhanced considerably by passing the received signal through a prediction error filter prior to correlate it with the pseudonoise (PN) sequence. In this thesis, nonlinear algorithms are developed suppress the interference. They include the LMS, RLS, and type of filters. Simulations show that the nonlinear gives significant advantages over the conventional approaches suppressing the interfering signals.