COLLABORATIVE SPECTRUM SENSING IN COGNITIVE RADIO USE USING SMART ANTENNAS
Abstract
- In this paper, a cooperative communication scheme using smart antenna is proposed for cognitive radio networks. This scheme expands the concept of cognitive radio in time and space. The wireless networks faced ever changing demands on their spectrum and infrastructure resources. The future wireless systems are supposed to have an impact on the efficient use of spectrum, reduction of cost, optimization of service quality and realization of transparent operation across multi technology wireless networks. Smart antenna is one of the emerging technologies which can fulfill the requirement. As Smart antenna makes use of spatial division of the signal rather than spectrum division, they can be considered for improving the performance of wireless communication. Using the cooperation, spectrum sensing accuracy and throughput of cognitive radio networks can be observably increased. The licensed users' detection and unlicensed users' transmission are almost carried on simultaneously. Spectrum sensing is the process of periodically monitoring a specific frequency band, aiming to identify presence or absence of primary users. Learn more in: Interference Statistics and Capacity-Outage Analysis in Cognitive Radio Networks. Cognitive radio has recently been identified as a potential relief to spectrum scarcity by improving temporal spectral efficiency. We investigate a flexible non-intrusive cognitive radio network based on smart antenna technologies. The proposed scheme exploits transmit beamforming to enable better spectral sharing between primary users and cognitive (secondary) users. As proposed, the cognitive transmitter equipped with antenna array forms transmit beamforming to keep the interference to primary receiver below a given threshold. By also adopting smart antennas at primary transmitters, we can significantly boost the successful transmission probability of cognitive users; thereby improving the spectrum utilization efficiency of the wireless communication networks.
