A New Access Algorithm in Cognitive Radio Systems

A new access algorithm in cognitive radio systems is proposed inthis paper, which can decrease primary users' access delay effectively and guarantee the access throughput fairness among primary users and secondary users. In the time domain, primary users apply 1-persisten access policy and secondary users apply exponential backoff retransmission policy; while in the frequency domain primary users select several suitable subcarriers as access channels and secondary users select only the subcarrier with the least interference temperature as access channel. Simulations confirm the perfect performance of the proposed algorithm.