Multicarrier communication system optimization based on modified Greedy bit loading algorithm

This paper deals with the optimization of multicarrier modulation technique using bit and power loading algorithm. The results from channel spectrum sensing are exploited for the optimization, having in mind the sensing imperfection. The simplest and most common method of spectrum sensing - the energy detection principle based periodogram method is considered. The new modified version of greedy algorithm has been proposed in order to limit the potential interferences caused by the imperfect spectrum sensing and resulting improper frequency band allocation, to cognitive radio primary users. As the inputs to the optimization, the measured TV band signals have been used. In order to get the real data samples, a Humax F3-FOX T receiver intermediate frequency signal was digitized using a GaGe CompuScope 12400 analog input PC card.