This thesis aims to clearly describe the cognitive radio and its components and operations. Moreover, it aims on describing the expected outcome from the most common techniques that are proposed for use in cognitive radios. In addition, it describes

采用遗传算法改进原基于神经网络的变换域通信系统接收方法，对收发两端频谱环境不一致条件下TDCS有效接收信息-The genetic algorithm is used to improve the receiving method of the transform domain communication system based on the neural network, and the TDCS can receive the information effectively under t