Measurement based radio environment database using spectrum sensing in cognitive radio

This paper presents a novel approach for radio environment database (RDB) techniques based on measurement to enable spectrum sharing in cognitive radio. The proposed database in this paper is used to estimate the received signal power of a primary user (PU) at a certain location by secondary users (SU). The received signal power is measured by the measurement nodes such as vehicles at different locations and is mapped in the database together with the information regarding the number of observations. Considering the Rayleigh fading characteristics in the stored data, we investigate the required margin for proper protection of the PU from the interference created by a SU. Through simulations, we show the relationship between the required number of observations at a certain location and the performance attained by the SU while also protecting the rights of the primary systems.