Run-length method for determining the segmentation length based on the segmentation long-code blind estimation

In this study, the blind despreading of long-code direct sequence spread spectrum signals (LC-DSSS) is considered. Qiu et al. presented a heuristic segmentation-based method to estimate the spreading code of LC-DSSS signals, which divided the received signal into far shorter temporal windows than the symbol duration, then spreading code was reconstructed from these short windows by computing the related covariance matrices. However, Qiu et al. did not consider the criterion of determining the segmentation length. By combining the matrix perturbation theory and run length property, the authors propose a run-length method for determining the segmentation length based on the segmentation idea, and this method can also be applied to long-code direct-sequence code division multiple access (LC-DS-CDMA) signals. Monte Carlo simulations for both LC-DSSS signals and LC-DS-CDMA signals are presented to demonstrate the effectiveness of the proposed method.