Various studies propose, massive portion of assigned spectrum are still unutilized, and
spectrum band usage are approximately 15% to 85%. Cognitive radio (CR) has been …

This paper provides an overview of major problems that are confronting wireless
communication with regard to spectrum use in general ie by all sectors, government, private …

Cognitive radio has been evolving as a promising technological solution to the problem of
frequency spectrum underutilization over the past decade in wireless communication …

The major hurdle that restricts the efficient utilization of radio spectrum is its inflexible and
rigid licensing scheme. This constraint limits the emerging wireless systems to operate in …

With the rapid development of wireless communication, the scarcity of spectrum becomes
more and more prominent. Cognitive radio is proposed to overcome the problem of low …

To achieve an efficient communication system, need for dynamic spectrum allocation
capability is required. Cognitive Radio technology helps the current communication network …

With today's ambition for more wireless devices and systems, the need for spectral
resources to accommodate these systems grows everyday, but the remaining spectrum …

Spectrum has been a very valuable resource in wireless communication systems. The
available electromagnetic radio spectrum is getting crowded day by day due to manipulation …

Cognitive radio (CR) is the enabling technology for supporting dynamic spectrum access:
the policy that addresses the spectrum scarcity problem that is encountered in many …

ABSTRACT A basic problem facing the future in wireless systems is where to find suitable
spectrum bands to fulfill the demand of future services. While all of the radio spectrum is …