PN code sequence estimation using tabu search

A novel and efficient method that can blindly estimate and synchronise to the PN code sequence of direct-sequence spread spectrum (DS-SS) signal is presented in a non-cooperative context. The method is based on maximum likelihood estimation (MLE) . The MLE of PN code sequence is hard to solve due to the multivariate nonlinear maximization problem. To solve the problem efficiently, this paper focuses on tabu search that is very general and conceptually much simpler than either simulated annealing or genetic algorithm. Both theoretical analysis and compute simulations show that this method can get a good estimation, even when the received signal is far below the noise level and the existence of co-channel multiple access interference.