Coding technique for out-of-band power emission reduction for multicarrier systems

In this paper, we introduce a new method for out-of-band power reduction of multicarrier (MC) communication systems. Recent years MC systems possess a dominated role in wireless access due to their ability to achieve high data rates and simultaneously high robustness to multipath effects and fading. Despite all these advantages, multicarrier transmission produces an essential out-of-band (OOB) interference. The OOB radiation leads to the wastage of the scarce spectral resources and may pose severe interference threats to adjacent wireless channels. In this paper, we propose a novel technique for reducing OOB radiations caused by high sidelobes in OFDM or MC-CDMA system. To reduce the OOB emissions in the MC-CDMA system, we propose the analytical criterion for spectrum efficiency estimation as far as low complexity algebraic algorithm for the proper waveform selection. The structure of the selected waveform provides suppression for radiation outside the signal necessary bandwidth. Being implemented in the OFDM system, proposed algorithm is used to calculate phases of cancellation carriers (CCs) which suppress the most powerful OOB emission components in the transmitted signal. In the final part of the document we consider primer of simplest precoding procedure for OFDM system which reduces its sidelobes by more than 10 dB in average at the cost of an inessential decrease in the information data rate.