A technique for sidelobe suppression in OFDM systems

In this paper, a new technique for sidelobe suppression in orthogonal frequency-division multiplexing (OFDM) systems is proposed and investigated. This technique can be applied to both pure OFDM and OFDM based multiple-access systems to improve spectral efficiency. Moreover, it can be utilized within OFDM based overlay systems to avoid interference towards the legacy systems operating in the same frequency band as the overlay system. The proposed sidelobe suppression technique is based on subcarrier weighting. The real-valued subcarrier weights are determined in such a way that the sidelobes of the transmission signal are minimized using an optimization algorithm which is capable to take several optimization constraints into account. Results show that sidelobes can be easily suppressed by more than 10 dB with the proposed technique. These results are achieved by allowing only a moderate loss in bit-error rate performance.