Design of Optimized BMU for QPSK Modulation scheme for Wi-MAX

Digital communication systems usually represent an increase in complexity over the equivalent analog system. Digital communication has become the most preferred option because of the increased scale of integration, sophistication and reliability of digital electronics for signal processing. In the proposed system the discrete data are EX-OR'ed with randomizer and Convolutionally encoded to transmit data securely. The data is rearranged in Block Interleaver and it is modulated by QPSK (Quadrature Phase Shift Keying) for increasing the signal strength by adding carrier signal and transmitted over to a AWGN (Additive White Gaussian Noise) channel. In the receiver side the received signal is demodulated using QPSK. The scrambled bits are rearranged by Block De-Interleaver and these bits are decoded by Viterbi Decoder. The extra bits decoded by Viterbi Decoder is removed by de-Randomizer which results in original discrete source data. The viterbi decoder increases the channel capacity by adding redundant bits to original bits, it performs Euclidean Distance approach to calculate the distance between the neighbouring signal points, so it performs complex operations. Efficient and secure data transmissions helps to achieve minimum computation.