This study develops a form of digital baseband Intra-Body communication for wideband transmission. A simplified circuit model of signal and noise is constructed to analyze the contribution of the high pass filter function of the electrostatic coupling Intra-Body communication system to wideband digital transmission in electrostatic coupling Intra-Body communication. A unit step function is presented to determine the maximum high pass 3dB pole that can ensure favorable signal quality in a baseband Intra-Body communication system. Body noise is measured to estimate the range of the high pass 3dB pole with good Signal to Noise Ratio. A 3.3Volt battery-powered FPGA is experimentally implemented to confirm the feasibility of the wideband Intra-Body communication system. The experimental results indicate that the digital baseband Intra-Body communication system supports a data rate of more than 16MPS.