A study of OFDM system applying frequency diversity

An OFDM system is widely known as a modulation scheme, which can reduce the effect of frequency selective fading. However, under a large frequency selective fading environment, it is difficult to demodulate correctly even with appropriate equalization. In this paper, an OFDM system applying a frequency diversity scheme is proposed. In this system, the same symbols are transmitted on several sets of carriers, and at the receiver end, these symbols are combined so as to maximize the signal to noise ratio. As the experimental result, it is shown that as the fading level becomes larger, the proposed system provides a larger gain in the bit error rate characteristics than the conventional system