A Spectral Method for Period Detection of PN Sequence for Weak DS-SS Signals in Dynamic Environments

In this paper, we develop a method based on the reprocessing of the power spectrum density (PSD) of direct sequence spread spectrum (DS-SS) signals with residual carrier, it can solve difficult problem of period detection and estimation of the pseudo noise (PN) sequence for weak DS-SS signals in dynamic environments. The method is developed from another method, which is based on the reprocessing of DS-SS signalspsila PSD in normal environments before. The first step of the method is to calculate the PSD of weak DS-SS signals in dynamic environments; then, we use the calculated PSD as an input signal to calculate their PSD again; the second PSD result will appear some regular tip-pulses at the integer-times of PN sequencepsilas period. We can detect and estimate the period of PN sequence from the interval measurement between the regular tip-pulses of the second PSD result in the end. The computer simulations show that the method can work well on lower signal to noise ratio (SNR) input signals with larger residual carrier in dynamic environments.