An MB OFDM system that includes a coder, responsive to a stream of at least one incoming symbol, to form therefrom a set including channel symbols that correspond to each incoming symbol, such that the channel symbols include the incoming symbol, the negative of the incoming symbol, the complex conjugate of an incoming symbol, and a negative of a complex conjugate of an incoming symbol; an output stage configured to: when two of the channel symbols are complex conjugates of one another, the output stage transforms one of the two channel symbols as the output of a single IFFT and the other of the two channel symbols by a reversal of the index of the output and creates OFDM symbols from the transformed symbols using an IFFT such that the two transformed OFDM symbols are copies of each other with inversed indices.