Study on the detection of the interference temperature for primary user

Opportunistic spectrum access (OSA) is a key technique enabling the secondary users (SUs) in a cognitive radio (CR) network to transmit over the “spectrum holes” unoccupied by the primary users (PUs). In contrast to OSA, with spectrum sharing (SS) is allowed to transmit regardless of the PU´s on/off status, provided that the resulting interference to PU is kept below a predefined threshold. In this paper, we focus on the maximum interference temperature of the primary users for secondary users´ spectrum access in spectrum sharing, which aims to get the minimum signal-to-noise ratio (SNR) of the PUs as quickly and precisely as possible. We propose a dichotomy algorithm with lower complexity and higher speed in contrast to the traditional full search algorithm. Numerous simulation results are provided to validate the proposed algorithm.