Analysis and Optimization of Ber for Secondary Users in Cognitive Radio Using Bbo and Pso Methods

Cognitive radio has been recognized as an answer to problem of limited spectrum in wireless communication. In this paper, the Bit-error-rate (BER) of secondary users in Cognitive radio network has been reduced using the Biography-based optimization (BBO) and Particle swarm optimization (PSO) techniques by maximizing the channel gains. For each secondary transmitter antenna, the channel gain for secondary to secondary link and secondary to primary link is optimized and the data is sent from an antenna using constrained difference selection method, showing maximum gain. Other than selection of antenna, another constraint for the optimization is the transmit power for secondary user. The BER has been improved for various values of Signalto-noise ratio (SNR) over which the transmission took place. It is proved from the simulation results that the average BER has been reduced by 8.571% and 5.229% with BBO and PSO respectively. It has been shown that BBO and PSO have a trade-off between reduction of average SNR and Time elapsed. BBO takes 0.048169 seconds for calculation whereas PSO does the same in 0.036195 seconds. At last, practical applications of both techniques are discussed.