Acquisition of m-Sequences using Soft Sequential Estimation
Lie‐Liang Yang, Lajos Hanzo · ePrints Soton (University of Southampton) · 2004
Abstract—A novel sequential estimation method is proposed for the initial synchronization of pseudonoise (PN) signals derived from -sequences. This sequential estimation method is designed based on the principle of recursive soft-in/soft-out (SISO) decoding, and we refer to it as the recursive soft sequential estimation (RSSE) acquisition scheme. The RSSE acquisition scheme exhibits a complexity similar to that of a conventional-sequence generator, which increases only linearly with the number of stages in the -sequence generator. Our simulation results also show that the acquisition time of the proposed RSSE acquisition scheme is also linearly dependent on the number of stages in the -sequence generator. Owing to the above properties, the employment of the proposed RSSE acquisition scheme is beneficial for the acquisition of long -sequences. Index Terms—Acquisition, initial synchronization, maximum-likelihood (ML) estimation, -sequence, pseudonoise (PN) signals, recursive decoding, sequential estimation, soft-in/soft-out (SISO) decoding, spread-spectrum signals.