Latest Trend for Interference Cancellation andRate Maximization of the Cognitive Networks

Cognitive networks are one of the recent trends in wireless communication. But still some drawbacks in these types of networks, main one is the interference caused by the cognitive user to the primary user or primary user to the cognitive user. Which will totally affect the performance of the entire system, to overcome from these kinds of problems we can use a technique called beam forming vector design at both sides. The beam forming vectors are designed such that the interference caused by the cognitive transmitter to the primary receiver and the interference caused by the primary transmitter to the cognitive receiver is completely nullified while maximizing the rate of both the primary and secondary links. The proposed algorithms also maximize the achievable rates of both links through uncoordinated beam forming. Beam forming exploits channel knowledge at the transmitter to maximize the signal-to-noise ratio (SNR) at the receiver by transmitting in the direction of the eigenvector corresponding to the largest Eigen value of the channel.