Digital Broadcasting. Improving the Error Characteristics of OFDM by Distributing Data Symbols in Frequency Domain.

In an OFDM system, it is possible to improve the symbol error rate degradation from the multipath by using an equalizer. However, received power of specific carriers drops down and carrier to noise ratio becomes lower for such carriers when an affection of multipath becomes big. This limits the improvement of the symbol error rate by the equalizer. In this paper, an OFDM system that distributes data symbols to all carriers by a unitary transform is proposed. By distributing data symbols to all carriers, it is possible to recover symbol data even if some carriers are lost by the multipath or because of interference. Good symbol error characteristics against multipath and narrow band interference are confirmed by theoretical analyses and computer simulations.