An Active Interference Management Scheme for Cognitive Radio Systems

Abstract

Key Words : cognitive radio, interference management, uplink system. ABSTRACTCognitive radio systems have been considered as a strong solution of frequency scarcity due to the limit of frequency resources. This paper proposed an active interference management scheme that the secondary system can coexist with the primary system in the same frequency band without interference. Using the proposed protocol, the secondary user acquires interference channel information and transmit/receive filter information and designs precoding matrix using these information. Since interference from the secondary systems are collected to unused subchannels of the primary system, the primary system can suppress interference without additional process. The secondary systems suppress interference from the primary system using whitening matched filter so that the spectral efficiency can be improved. Numerical results provides that the proposed scheme improves performance of the secondary systems without interference to the primary system and do not degrade performance of the primary system even if the number of the secondary systems increases. First

On the Secrecy Capacity in Cooperative Cognitive Radio Networks

“…Under a CRN, secondary users need to sense the spectrum to detect spectrum holes that are not used by primary (licensed) users. When using the resources that primary users are using, the secondary users and to limit the harmful interference that may be caused to the primary users [2][3][4] . Recently, physical layer security has attracted significant interest in the research community as the information security becomes crucial for pervasive and personalized wireless devices [5][6][7][8] .…”