Conventionally we use discrete Fourier transform (DFT) in OFDM system. This book presents the simulation of 4 Quadrature Amplitude Modulation (QAM) orthogonal frequency division multiplexing (OFDM) baseband system and channel estimation which uses inverse discrete Hartley transform (IDHT) and discrete Hartley transform (DHT). As the calculation of DHT and IDHT involves real operations hence the computational complexities are less as compared to DFT and IDFT. Moreover as IDHT is same as DHT hence we can use same hardware for both, while the DFT and IDFT require separate hardware to implement. As compared to DFT based OFDM system, the simulated DHT based OFDM system achieves approximately the same transmission performance with less computational complexity and hardware requirements.