Method suitable for low signal to noise ratio channel environment half-frame timing detection and CP type detection

The present invention discloses a method suitable for the low signal to noise ratio channel environment half-frame timing detection and the CP type detection. The method comprises the steps of carrying out the symbol mapping on a reception end according to a sign function firstly; then constructing a new metric function Rc(d) by utilizing the central symmetry of a PSS sequence in the time domain, the conjugate symmetry of a secondary synchronization signal (SSS) sequence in the time domain, and the different relative positions of the PSS sequence and the SSS sequence under different CP types; after the metric function is obtained, at each moment, obtaining the weighted average value of K metric function values which are counted from the moment to obtain a dynamic threshold at the moment; finally, locking a timing position by contrasting the metric function and the corresponding dynamic threshold, at the same time, obtaining the CP type. The method of the present invention, can obtain the half-frame timing pos