Abstract: The accuracy of traditional method for frequency detection based on auto-correlation is not high,and a new method for frequency of weak sinusoidal signal in powerful noise based on dual-channel is introduced in this paper. Using the principle of multi-layer correlation and the curve fitting technique with only four points and uses multi-point frequency compensating technique. The simulations proves its feasibility and effectiveness to detect the weak sinusoidal signal and having much higher resolution than auto-correlation method. So it has some practical value.

Key words: Weak signal, Frequency detection, Multi-layer cross correlation