ORTHOGONAL MULTIPLE CARRIER DATA-TRANSMISSION

In this paper, the idea of data transmission by essentially using the discrete Fourier transform (DFT) algorithm, the idea of overlapped but orthogonally sampled multiple data transmission channels, and the idea of subband signal processing by means of DFT polyphase filter banks are combined. The main result in a novel orthogonal multiple carrier (OMC) data transmission system with high computational efficiency and high bandwidth efficiency. Intersymbol interference is avoided by choosing each channel as a Nyquist system. The problem of unavoidable crosstalk between adjacent channels is solved by sampling the equally spaced zeros of the crosstalk impulse response. It is shown that in a critically sampled DFT filter bank the space between the zeros exactly equals one symbol period. The time offset of half a symbol period between the zeros of the real part and the zeros of the imaginary part of the crosstalk impulse response leads to a special staggering technique with time offset. Finally the structure of the polyphase filter banks is optimized resulting in fast Fourier transforms of half of the original length.