OFDM混合调制信号在认知网络中的应用

摘要

对OFDM混合调制信号进行了谱相关分析,并将其应用到认知网络中.在采用OFDM混合调制信号传输的认知网络中,利用信号的循环平稳特性可以快速识别出信道空闲、认知信号传输、主用户信号传榆和两种信号混叠这四种状态,为认知网络中认知信号的快速可靠接入和退出提供了保障.进一步利用混合调制的位置来标记不同的认知网络,认知节点可以区分不同认知网络信号.在提出的认知网络应用模型中,传输和接收设备较简单,而且不需专门的信道来传输控制命令,节约了带宽.仿真结果显示,在认知网络中,该模型可以提高频谱利用率,使通信系统的性能得到改善.%The spectral correlation analysis of orthogonal frequency division multiplexing (OFDM) blending modulation signal is conducted. The application of OFDM blending modulation signal was achieved in cognitive network. Four kinds of channel states, that is, spectrum vacancy, cognitive signal transmission, primary signal transmission and mix transmission of two signals, can be distinguished agilely by using their distinct cyclic spectrum features, which help the cognitive signal in the cognitive network to access to or quit from channels quickly and reliably. The position of inserting modulation as a feature, which cognitive node as an unique identifier in network identification can distinguish the different cognitive network signals. The design of transmitter and receiver are simple and need no a static common control channel with the proposed model of cognitive radio, which promise greater spectral-usage efficiency. Simulation results show that the proposed model can improve spectral-usage efficiency and performance in cognitive radio networks.