关键词: 直接序列扩频, 自适应干扰消噪, 四阶累积量, 载频估计

Abstract: Due to its low power spectral density，the direct sequence spread spectrum signal is always submerged with the back-ground noise，so that it is difficult to reconnoiter the signal.Although the 2-D slice of the fourth-order cumulant can effectively suppress the Gaussian white noise in the abstract，the effect isn’t good when SNR（Signal to Noise Ratio） is lower.An improved estimation method for the carrier frequency of Direct Sequence Spread Spectrum（DSSS） is proposed.An adaptive noise cancellation is added in advance of usual fourth-order cumulant 2-D slice，so that SNR is improved under the background of Gaussian white noise.According to the idea，this paper constructs a module based on the system view software and realizes the accurate estimation of carrier frequency for DSSS under low SNR.The validity of this method is shown by computer simulation.

Key words: direct sequence spread spectrum, adaptive noise cancellation, fourth-order cumulant, carrier frequency estimation