US Patent 8649364 Hybrid subcarrier mapping method and system

A method and system of accommodating different mapping schemes in a transmission using an orthogonal direct sequence spread spectrum technique in which input data to a transmitter is spread by conversion into a sequence of complex numbers modulated for N-point discrete Fourier transform (N-point DFT), subcarrier mapping, M-point inverse discrete Fourier transform (M-point IDFT), and cyclic prefix (CP) insertion; the spread and modulated data is transmitted to and received by a receiver; and the received data is despread demodulated for cyclic prefix (CP) removal, M-point discrete Fourier transform (M-point DFT), subcarrier demapping and equalization, and N-point inverse discrete Fourier transform (N-point IDFT).