Orthogonal Frequency Division Multiplexing (OFDM) is a very attractive technique for high bit rate data transmission in a multipath fading environment that causes intersymbol interference (ISI). In this paper, two steps are used to improve the error rate performance of OFDM system. First, we proposed the Slantlet Transform (SLT) used instead of Fast Fourier Transform (FFT) to obtain high orthogonality properties between subcarriers and hence reduce (ISI). Second, we proposed the Low Density Parity Check (LDPC) Codes for the proposed SLT-OFDM system to improve the Bit Error Rate (BER) and Packet Error Rate(PER) performance.
The goal of the proposed SLT method is to reduce the energy needed to transmit data on a fading channel and to decrease the number of complex computations(addition and multiplication) and hence increase the speed of the system in addition to obtaining high orthogonality between subcarriers. Hence, the proposed LDPC-based SLT-OFDM system is a promising solution to high efficient data transmission over fading channels. The proposed system has been tested and validated using MATLAB 7 package.