Blind code timing estimation for DS-CDMA signals in unknown colored noise
In previous years, the MUSIC timing estimator were proposed for direct-sequence code-division multiple access (DS-CDMA) signals. It has been generally assumed that the channel noise is temporally white. However it may be invalid in practice due to, for instance, the presence of some narrowband interference or the lumping of secondary users into with the noise. We consider blind code timing in unknown colored noise by using the matrix decomposition technique. A subspace-based code timing estimation algorithm is presented and its performance is evaluated by computer simulation and compared with the MUSIC method. It is proved that the proposed timing estimation algorithm provides better performance than the MUSIC method in colored noise.