Blind adaptive techniques used for smart antennas in CDMA systems

The smart antenna system is a promising technique for supporting high traffic demand in the third generation mobile systems. Also, Direct Sequence Code Division Multiple Access (DS-CDMA) is considered a strong candidate to support multimedia services in third generation wireless systems as it increases spectrum efficiency. Using Smart Antennas in CDMA wireless systems makes it possible to meet the increasing demand in mobile communication services. In this research, we investigate the performance of the different blind adaptive array algorithms in CDMA systems. Three novel algorithms have been developed, namely the Sample-based Recursive Least Squares Despread Respread Multi-Target Array (Sample RLS-DRMTA), the Affine Projection Despread Respread Multi-Target Array (AP-DRMTA) and the Conjugate Gradient Despread Respread Multi-Target Array (CG-DRMTA). A MATLAB simulation testbed was created to evaluate the performance of these algorithms and compare them with the performance of the Least Squares Despread Respread Multi-Target Array (LS-DRMTA), the Least Squares Despread Respread Multi-Target Constant Modulus Algorithm (LS-DRMTCMA) and the Block-based RLS-Despread Respread Multi-Target Array (Block RLS-DRMTA). Simulations results have shown that the proposed algorithms can outperform both the LS-DRMTA and the LS-DRMTCMA under all conditions and give comparable performance to the Block RLS-DRMTA.