OFDM baseband modulation technology based on VHDL

In order to improve the transmission velocity in mulitipath fading wireless channel, the high speed OFDM technology receives increasing attentions in mobile communication. Modulation programs are designed with VHDL based on the principle of OFDM in the paper. First, after OFDM fundamental is introduced; two main advantages are obtained via discussing spectrum utilization ratio of OFDM. Then, from the results of VHDL simulation, the realization of baseband operations, such as interleaver, subcarrier modulation, IFFT and adding CP, are presented. Finally, implemented programs are validated on the actual implement system. Experimental results indicate that setup time corresponding to transmission velocity is only 71.05µs and steady time is approximately 6 times as setup time, that is, not only achieving the high speed transmission, but also supplying adequate modulation time.