Reducing computational complexity of cancellation carriers algorithm by using unique offline optimized pulses

Cancellation carriers' method is a well-known technique in the OFDM overlay systems that employs a few optimized-weighted sinc-shape subcarriers at the edges of signal spectrum to mitigate the out-of-band power leakage and provide approximately free-interference transmission in the spectrum sharing scenarios. More employed cancellation tones can suppress more out-of-band power at the cost of further computational complexity and spectral inefficiency. In this paper, a unique semi-orthogonal pulse which is designed offline is proposed that compared to using conventional cancellation carriers can mitigate a certain out-of-band power through less complexity. The simulation results for a scenario with 64 OFDM carriers show that by employing three offline optimized pulses, which occupy five OFDM subcarriers at each side of the signal spectrum, one can achieve a certain out-of-band power suppression almost equal to condition when five conventional cancellation carriers are used at each side of the spectrum with the reward of 54% - 70% lower computational complexities.