In the last few years, there is a rapid growth in the area of wireless communications and the demand of limited wireless spectrum has increased significantly. In early days, the spectrum was assigned by following static allocation schemes. This fixed spectrum assignment policy results in under-utilization of scarce radio spectrum.The study by Federal Communications Commission (FCC) shows that the spectrum is available but its usage is not efficient. Cognitive Radio is a new technology that increases the utilization of available spectrum by implementing dynamic allocation schemes.In this...