Combined Wiener and Double Density Discrete Wavelet Filter Based Algorithm for Noise Reduction in CDMA Receiver
Wavelets are considered as powerful signal processing tools that provide an effective alternative to conventional signal transforms. Because of its unique characteristics, the spread spectrum plays an important role in CDMA (Code Division Multiple Access) communication system and has been first used for military applications. The Spread Spectrum communication via, discrete wavelet transform and thresholding becomes effective now-a-days, because it works well in the lower SNR values. In addition, the Wiener filter is used to improve the performance further. This paper proposes a new technique to improve the signal-to-noise ratio in the enhanced speech signal by using combined Double Density Discrete Wavelet Filter (DD-DWF) with thresholding and Wiener filter. This method is of explicit physical meaning and can be implemented conveniently.