In the last years, a major transition from analog to digital modulation techniques has occurred and it can be seen in all areas of wireless communication, satellite and cellular systems. This paper give the brief description of digital communication system. Digital communication is more reliable, secure and efficient than that of analog communication. In digital communication, BPSK is most important and efficient technique in terms of signal power. In this paper, BPSK modulator and demodulator are purely design by using Hardware Description Language (VHDL) and implementing it on Spartan 3E FPGA kit.