Rejection of Narrow-Band Interference in a Delay-Lock Loop Using Prediction Error Filters

Hiroji KUSAKA  Toshihisa NAKAI  Masahiro KIMURA  Tetsuya NIINO  

IEICE TRANSACTIONS on Communications   Vol.E76-B   No.8   pp.955-960
Publication Date: 1993/08/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Spread Spectrum Techniques and Applications)
spread spectrum,  interference,  delay lock loop,  prediction error filter,  

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A narrowband interference in direct sequence spread spectrum communication systems also affects the characteristics of a delay lock loop. In this paper, the delay errors of a baseband delay lock loop (DLL) in the presence of the interference which consists of a narrowband Gaussian noise and several tones are examined, and when a filter is used to reject the interference, the characteristics of the DLL are analyzed using the Fourier method. Furthermore, from the calculation results of the delay error in case where a prediction error filter with two-sided taps is used as the rejection filter, it is shown that the filter is necessary to keep the DLL in the lock-on state.