OFDM modem is used to encode the digitize voice/data and transmit on 45, 70 & 140 MHz IF frequencies over multiple carriers and decode on the receiving side using OFDM methodology. It uses 64QAM/16QPSK mode modulation and demodulation techniques over the 256 carriers. Convolution encoding and Viterbi decoding is provided to ensure error free data transmission and reception. It uses USB port for data transfer. Software is developed in FPGA for modulation, demodulation & implementation of OFDM algorithms(FFT, IFFT, Channel estimation phase correction and FEC)