As the conventional insertion sequence lowers the bandwidth efficiency

a superimposed training sequence timing synchronization method is proposed.Using the complex sequence in the time domain

a conjugate symmetrical structure is constructed and the sequence linearity with mirror inverse function features of the real numbers obtained after IFFT is linearly superimposes on OFDM symbols so as to remove the drawback that the traditional insertion sequence monopolizes the transmitting power.Simulation results indicate that compared with the conventional ones

this method has higher synchronization accuracy rate and improves the system spectrum efficiency in low SNR.