The spread of JTIDS waveform is used to synchronize the system, and the information is transmitted by M-ary spread spectrum and MSK modulation. According to this characteristic, the JTIDS waveform is used to match the correlation peak position in the receiver. One way is to directly convert the IQ data of the AD filter into the matching correlation, and the other is to carry out the correlation of the AD sampling data only after the symbol bit is converted to the lower frequency. In this paper, the performances of the two methods are compared.