DEsign and performance analysis of DWT/FFT based OFDM systems

In this paper, a software reference model for Orthogonal Frequency Division Multiplexing (OFDM) is developed and verified for its functionality that can be adopted for wireless communication applications. BER and functionality of the developed OFDM model is analyzed for Fourier based OFDM (FFL-OFDM) and Wavelet based OFDM (DWL-OFDM) systems for AWGN Channel and results are compared. DWL-OFDM is implemented using zero paddmg and vector transposing for transmitting the OFDM signal and likewise the zeroes are discarded at the receiver. Modulation results for 16-QAM, 32-QAM, 64-QAM, 128-QAM and 256 QAM are noted for both DWL and FFL based OFDM models. It is found that DWL based OFDM achieves better BER results compared with FFL-OFDM model. DWL-IDWL based OFDM model developed is analyzed for its performance by considering various wavelets such as Haar, Db-3, Db-4, bior.3.3, bior5.5, rbior.3.3 and rbior5.5. The OFDM model is developed using Simulink in MATLAB, various test cases have been considered to verify its performance. It is seen that Haar wavelet m DWL-OFDM outperforms FFL-OFDM by approximately 10 dB at a BER of 0.95.