Spectrally Precoded OFDM with Cyclic Prefix

Spectrally precoded orthogonal frequency-division multiplexing (OFDM) is a promising rectangularly pulsed OFDM signaling format which can provide very small power spectral sidelobes, while allowing for efficient implementation by fast Fourier transform and guard insertion. In this paper, a general constraint on spectral precoding is developed for OFDM signals with cyclic prefix (CP-OFDM) to warrant the desirable spectral property that the power spectral sidelobes decay as f^-2K-2, with K a preassigned integer. Specifically, block partitioning is adopted to facilitate the precoder design of such spectrally precoded CP-OFDM. New correlative and orthogonal precoders are also devised. It is analytically shown that the proposed spectrally pre- coded OFDMs can provide better choices of spectral efficiency and average error performance than conventional spectrally precoded OFDMs.