An interference avoidance method for cognitive radio in white space

This paper presents a new interference avoidance method based on Genetic Algorithm (GA) to obtain an optimal set of transmission parameters for cognitive radio-based multicarrier systems operating in the same band as digital television (DTV). To this end, both interference analysis techniques and interference temperature model are employed to find out the maximum allowable transmit power for each subcarrier and an interference temperature limit at DTV receiver, which are useful to build a set of coexistence constraints for chromosomes in GA implementation. In addition, besides minimizing interference accumulated in DTV band, this paper also attempts to minimize bit error rate (BER), maximize throughput, and minimize transmit power for the multicarrier systems by using a multi-objective fitness function derived in this work.