Complementary Sequence Construction for Constant-Envelope OFDM Transmission Enabling Nonlinear Amplification and Clipping.

The high PAPR of OFDM transmission leads to power/cost inefficiencies in amplifier use and/or spectral noise from clipping effects. To avoid these issues, we propose transmitting a complementary sequence pair whose aperiodic autocorrelations sum to a delta function in such a way that the amplitude of the signal is constant. This enables the use of low-cost nonlinear amplifiers operating at full power. The sequence pair is constructed iteratively, by sequential encoding of information symbols onto the pair such that the sequences remain complementary. The structure of these sequences and the resulting constant-envelope signal are analyzed, leading to methods of symbol extraction and the results of a decoding error. Finally, we extend the discussion to two dimensional sequence pairs, for use in mmWave/MIMO systems where the inefficiencies of a high PAPR are even more acute.