提出了一种基于Otsu准则的TDCS自适应门限选择方案,该方法首先对信道感知的频谱幅值进行灰度映射,然后利用Otsu准则将频谱灰度分为背景噪声和干扰2类,同时确定出最佳的分类阈值作为TDCS剔除干扰的判决门限。该方法能够根据对信道的感知结果动态地搜索最佳判决门限,具有很强的自适应能力。仿真结果表明:文中所提方法在信道背景噪声变化时表现出比传统方法优异的性能,尤其是当背景噪声升高到一定程度时,传统固定门限值方法的通信系统将不能正常工作,而文中所提方法还具有良好的通信性能。
A new TDCS adaptive threshold selection algorithm based on Otsu guidelines is proposed. In this algorithm, the spectral amplitude of the channel sensing are gray mapped, the spectrum grayscale is divid ed into background noise and interference by using Otsu guidelines, the best classification threshold is de termined as the TDCS interferencerejecting decision threshold as well. The method is of strong adaptive capacity based on the perception of the channel and can be used to search the best decision threshold dy namically. Simulation results show that, the proposed method demonstrates superior performance than the traditional methods in the changing of channel background noise, especially when the background noise is increased to a certain extent, the communication system with traditional fixed threshold method will not work properly, but the use of the proposed method still makes the system performance good.