Spectrum sensing approach of CI/OFDM based software defined radio transceiver in Cognitive Radio (CR)

摘要

Cognitive Radio (CR) detects a unused licensed spectrum and assign it to secondary users using particular assigning method without interfering with the transmission of licensed user. Orthogonal Frequency Division Multiplexing (OFDM) driven Software Define Radio (SDR) device senses the status of a spectrum availability and assign to the CR users without less interference. Carrier-Interferometry OFDM (CI/OFDM) based SDR had been proposed recently to reduce interference among the SDR users. In this paper, CI/OFDM based SDR has been used in CR system to assign the licensed spectrum to secondary users under certain restriction with less interference with the licensed spectrum. The user detection probability and miss detection probability of the proposed SDR device has been also derived in this paper. We have numerically calculated the detection probability and interference corresponding to the threshold value and, the result shows that the overall user detection probability of the proposed SDR is higher than the traditional SDR terminals. The proposed CI/OFDM SDR also detect any target frequency spectrum by searching CI-codes along with frequency band, modulation etc. of the transmitted signal.