A new method of space-time group multiuser detection for multi-code DS-CDMA

We consider a system where users, each with a single antenna, transmit to a receiver with multiple antennas and spread by using multi-code. In this system, users are organized in groups and allocated a unique PN code within the same group and a unique orthogonal code for the i th basic rate. Using affine transform and subspace projection, we get the interesting signals. Then a generalization of the layered space-time algorithm is performed to further remove the remaining interference. The capacity and spectral efficiencies are improved.