A bootstrap multi-user detector for CDMA based on Tikhonov regularization

A novel multi-user detection (MUD) technique for CDMA systems is introduced. The new method is well suited for cases in which the code cross correlation matrix is ill-conditioned. In practice, this case coincides with having code lengths approximately equal to the number of users - a desirable condition in terms of bandwidth efficiency. Our approach employs an iterative formulation of a well-known regularization method for linear inverse problems, which is suited to the MUD problem. The technique allows knowledge of the finite set in which the solution belongs to be exploited in a computationally efficient manner in order to improve the quality of the estimate iteratively.