US Patent 7860180 OFDM modem for transmission of continuous complex numbers

The invention enables the transmission of continuous complex numbers using a symbol based transmission scheme such as OFDM. Accordingly, complex numbers are mapped to the constellation map, enabling a fine granularity of constellation points. This scheme may be used, for example, in the transmission of video where the coefficients representing the higher frequency of each of the video components, as well as the quantization error values of the DC and near DC components, or some, possibly non-linear transformation thereof, are sent as pairs of real and imaginary portions of a complex number that comprises a symbol.