In extremely low rate scatter communication system, traditional detection technique such as coherent detection may cause serious system deterioration,and is inadaptable to the variation due to carrier frequency offset at both ends of communication system. Aiming at this problem, the failure mechanism of conventional detection method for scatter channel at extremely low rate is analyzed, and a FSK demodulation method based on discrete short time Fourier Transform （DSTFT）is proposed, including its realization principle and diversity combining method. At last ,the performance simulation and analysis are made ,which indicate the performance is favorable and the method can be applied to projects.%对于极低速率散射通信系统,传统的检测技术如相干检测,会导致通信系统性能恶化非常厉害,已不能适应通信系统两端载波频偏造成的变化。针对此种情况,在分析了传统检测方式失效机理的基础上,提出了一种基于离散短时傅里叶变换（DSTFT）检测的FSK解调方式,给出了其实现的原理和方法,最后对其性能进行了仿真和分析,仿真结果表明性能良好,可考虑应用于工程中。
展开▼
