Blind adaptive CDMA processing for smart antennas using the block shanno constant modulus algorithm

A space-time blind adaptive processing algorithm is proposed for the uplink base station receiver in a direct-sequence code-division multiple-access (DS-CDMA) cellular system. The proposed algorithm, called the space-time block Shanno constant modulus algorithm (STBSCMA), minimizes a constant modulus algorithm (CMA) objective function in a bilinear function structure combined with penalty terms for both spatial and temporal domains. The proposed algorithm rapidly converges to the stationary points at fewer iterations than block conjugate gradient CMA (CGCMA) and block gradient descent CMA (GDCMA). STBSCMA finds the critical points of the objective function. STBSCMA also recovers rapidly from an abrupt change of channel. The proposed algorithm structure requires relatively low computational complexity to improve the receiver performance for space-time processing in the DS-CDMA system.