关键词: 认知无线电, 多带联合频谱感知, 差分进化算法, OFDM系统, 门限向量优化

Abstract:

In view of the slow convergence speed and low convergence precision of the threshold vector optimization in the multi-band joint spectrum sensing of the OFDM system,the paper presents a method that can optimize threshold vector based on the differential evolution algorithm.According to the multi-carrier digital modulation theory and the excellent frequency selectivity of the OFDM system,the algorithm makes full use of the fast convergence speed and strong global optimization ability of the differential evolution algorithm and guarantees that the optimal threshold vector is obtained by considering sub-channel information when the main user is under certain limited interference.The experimental results show that the proposed algorithm greatly improves the convergence time and convergence precision;and under certain limited interference,the total throughput of the cognitive system reaches the maximum.

Key words: cognitive radio;multi-band joint spectrum sensing;differential evolution algorithm;OFDM system;threshold vector optimization