DWT, SWT AND DWT-SWT FOR INDOOR OPTICAL WIRELESS COMMUNICATION SYSTEM

In this paper, different wavelet techniques are used to improve the system performance. In any communication system, the amount of noise and its efficiency to give output can determine the performance of that system. In optical wireless communication system Fluorescent Light Interference (FLI) affects a signal a lot. Here, in this paper three methods are to reduce the effect of noise from a digital signal, i.e. method1 Discrete Wavelet Transform (DWT), method 2 Stationary Wavelet transform (SWT) and method 3 Discrete Wavelet transform-Stationary Wavelet Transform (DWTSWT). Through sub band coding in DWT signal is divided into lower sub bands of high and low frequency respectively of unequal size; while in SWT the decomposed signal have sub bands of equal size. In DWT-SWT the high frequency components of both DWT and SWT are added. Using On-Off Keying and Pulse Position Modulation, the comparison between the three techniques is described here to improve the whole enactment of the Indoor Optical Wireless Communication System.