Application of Adaptive Filter Using Adaptive Line Enhancer Techniques

The paper discusses a method for detection of weak signal having low signal to noise ratio (SNR). SNR can be improved using fixed filters or using a suitable adaptive filter. In practical application, the statistical characteristics of signal and noise are usually unknown. The design of fixed filter is based on priori knowledge of both the signal and noise. Adaptive filters, on the other hand, have the ability to adjust their own parameters automatically and their design requires no priori knowledge of signal or noise characteristics. The adaptive line enhancer is applied before the FFT analysis to improve the detection performance. Performance of ALE using LMS and the RLS algorithms and a set of block processing algorithms BLMS, BAP are also compared. We simulated the adaptive filter with MATLAB, and the results prove its performance is better than the use of a conventional digital filter.