Suboptimal MMSE multiuser receiver design for DS-CDMA multirate systems using spectral correlations

A new expression for the MMSE (minimum mean-square error) linear receiver is derived in this article for a multirate system using spectral correlation between cycle frequencies and, based it, propose a new design method for the "best" suboptimal linear receiver which requires only the knowledge of bit rates in the system. Computer simulation reveals that it is an efficient design method.