Implementation of OFDM by using wavelet for optimization of wireless communication system

Although tremendous research has conducted on high speed communications but still number of research works which are reported in literature are fails to meet the real time requirement. The main drawbacks in the conventional communication techniques are low spectral efficiency, lack of high rate, interferences, etc. The OFDM communication model overcomes the drawbacks of conventional communicational model and offers the high data rate, and high spectral efficiency. Although OFDM has many advantages over FDM but it suffers from inter carrier interference and inter symbol interference when multiple carriers are used and due to this interferences loss of Orthogonality happens, in order to overcome these interferences usage of cyclic prefix has become mandatory. But usage of cyclic prefix shows huge negative impact on bandwidth efficiency as the cyclic prefix approach consumes nearly 20% of bandwidth and BER performance too affected by CP. In this paper a novel wavelet based OFDM model is presented which is mainly intended to provide good Orthogonality and better spectral efficiency using various modulation techniques, the unique thing in the usage of wavelet based OFDM is it does not need the cyclic prefix, CP decreases bandwidth efficiency. But wavelet increases bandwidth and when bandwidth increases simultaneously spectral efficiency increases. Finally the usage of the wavelet based OFDM shows improved BER over conventional FDM communication model. The simulation results indicates the usage of wavelet based OFDM in place of Fourier based OFDM in wireless system and finally the comparison between wavelet based OFDM and DFT based OFDM. In this paper for simulation purpose Additive white Gaussian noise channel (indoor channel) and Stanford University Interim (SUI) channels are used. Here Sanford University channel works like outdoor channel. In every channel and for every modulation scheme wavelet gives improved Bit Error Rate.