Spectral sculpting for OFDM-based Cognitive Radio systems by SVD precoding scheme

To suppress the interference to Licensed Users (LUs) in orthogonal frequency division multiplexing (OFDM)-based Cognitive Radios (CR) systems, a novel spectral precoding scheme is proposed. The precoder matrix is obtained by the singular value decomposition (SVD) algorithm. Analysis and simulations show that the proposed scheme can significantly suppress the power interference by tens of decibels in contrast to the uncoded schemes at a little cost of precoding efficiency. Meanwhile, the peak-to-average-power-ratio (PAPR) is expected to be unaffected and the bit-error-rate (BER) performance over multipath fading channel is improved.