Reduction of Paper in OFDM System Using Haar Wavelet Based Approach

Communication is one of the important aspects of life. With the advancement in age and its growing demands, there has been rapid growth in the field of communications. Signals, which were initially sent in the Analog domain, are being sent more and more in the Digital domain these days. For better transmission, even single – carrier waves are being replaced by Multi – carrier systems like CDMA and OFDM are now – a – days being implemented commonly. Orthogonal frequency-division multiplexing (OFDM) is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. Priority is given to minimizing the interference, or crosstalk, among the channels and symbols comprising the data stream. OFDM is essentially identical to coded OFDM (COFDM) and discrete multi-tone modulation (DMT), and is a frequency-division multiplexing (FDM) scheme used as a digital multicarrier modulation method. A large number of closely spaced orthogonal sub-carrier signals are used to carry data on several parallel data streams or channels. The primary advantage of OFDM over single-carrier schemes is its ability to cope with severe channel conditions without complex equalization filters. But the large Peak – to – Average Power Ratio of these signal have some undesirable effects on the system. In this thesis we have focused on learning the basics of an OFDM System and have undertaken HAAR WAVELET transformation method to reduce the PAPR in the system. Finally we compare BER performance of our proposed OFDM with the conventional OFDM over different channels to show the excellent performance of our proposed OFDM model.