A Survey: A Cognitive Radio for Wireless Communication

As we know that for communication we require radio spectrum resources.And our spectrum is naturally limited resources.We can't create resources but we can reuse the available resources.As earlier spectrum allocation done based on Fixed Spectrum Allocation (FSA).Due to this our spectrum is underutilized and result in spectrum scarcity.Now a days as the rapid growth of wireless technology, government regularity like FCC having a problem to satisfied the user demand.To solve this problem cognitive radio is the resent trends to over utilize the available spectrum.Cognitive radio utilizes the dynamic spectrum allocation to utilize the available spectrum resources.This paper surveys the concept of cognitive radio, overview, different sensing techniques, standard and recent advancement in research technology.