Scrambling Code Blind Identification in SDH Signal Intelligent Reception

The blind identification of scrambling codes is an important issue in intelligent reception of unknown synchronous digital hierarchy (SDH) lines. In this paper, the blind identification of scrambling codes is studied in three aspects: extraction of scrambling code sequence with error codes, determination of scrambling code primitive polynomials and initial attack of linear registers. A method for deducing scrambling primitive polynomials based on higher order statistics is proposed. The method based on partial exhaustive search initial state attack method based on Walsh transform is improved to handle the specific problem in unknown SDH lines. The proposed scheme can identify the scrambling code of the unknown SDH line completely, and has better fault-tolerant performance and low computational complexity.