Partial coherent detection method of fast attenuation channels

The invention discloses a partial coherent detection method of fast attenuation channels. Advantages of coherent detection and non-coherent detection are fully utilized in demodulation, problems in using coherent detection and non-coherent detection independently are avoided as possible, a receiver is used to obtain partial channel state information, and coherent detection is combined with non-coherent detection; when the signal to noise ratio is low, coherent detection is mainly used; and when the signal to noise ratio is high, non-coherent detection is mainly used to avoid the floor effect and high channel estimation complexity caused by coherent detection. Due to utilization of statistical values of channel change, frequent channel estimation is not needed in a coherent demodulation portion, and with increase of the signal to noise ratio, the determination rule further approaches non-coherent demodulation, and the channel estimation frequency further decreases.