A novel out-of-band emission suppression method in future wireless communications employing filtered orthogonal frequency division multiplexing waveform

In order to achieve flexible configuration and asynchronous transmission of different subbands (SBs), SB filters are utilized in filtered orthogonal frequency division multiplexing (f-OFDM) systems to isolate different SBs efficiently. Nevertheless, the price is the insertion of some intrinsic interference.Therefore, the suppression of the out-of-band emission (OOBE) between SBs is essential for the system performance improvement of f-OFDM. According to the system structure of f-OFDM, an optimization design model based on active interference cancelation (AIC) is proposed in this study, and the optimization design model is solved through second order cone programming. Furthermore, the effectiveness of the proposed AIC algorithm in OOBE suppression is verified by computer simulations. To the whole system, the OOBE suppression also means the decrease of inter-SB interference (ITBI). In addition, the influences of main parameters, such as the number of the cancelation carriers (CCs), on the OOBE suppression performance of the proposed AIC algorithm, are simulated and analyzed. Moreover, some intrinsic characteristics of the proposed algorithm in parameter configuration are revealed in terms of power spectral density (PSD) and bit error ratio (BER).