Symbol-aided approach to nonlinear distortion cancellation for self-heterodyne OFDM direct conversion receivers

We propose a symbol-aided approach to nonlinear distortion cancellation and data demodulation in self-heterodyne direct conversion (SHDC) receivers for discrete Fourier transform (DFT)-based orthogonal frequency division multiplexing (OFDM) systems. In order to cancel the intermodulation distortion generated at the square-law device output in the receiver, the SHDC transmitter generates an OFDM symbol followed by the next symbols having a phase difference of 90 degree. By using this approach, quadrature modulation can be supported with direct conversion. The advantages of the proposed technique are demonstrated through the computer simulation.