A new blind adaptive interference suppression scheme for acquisition and MMSE demodulation of DS/CDMA signals

In this paper, we present an efficient blind algorithm for estimating the c ode timing of a desired user in an asynchronous direct-sequence code-divisi on multiple-access (DS/CDMA) system over frequency-nonselective-fading chan nels. The proposed algorithm acquires the code timing explicitly and result s in a near-far resistant minimum mean-squared error (MMSE) demodulation wi thout requiring the knowledge of the timing information, amplitudes, and tr ansmitted symbols of all transmissions, The only required knowledge is the information of the signature sequence used by the desired transmission. Sev eral computer simulations are done for additive white Gaussian channels, Ra yleigh fading channels, and two-ray Rayleigh fading multipath channels, res pectively. Numerical results show that the new algorithm is near-far resist ant to the multiple-access interference (MAI) in the DS/CDMA system.