A new approach to unified performance analysis of randomly-spread CDMA systems over multipath fading channels via crosscorrelation matrix non-asymptotic average eigenvalue distributions

A new unified method for closed- form theoretical performance analysis of randomly-spread CDMA systems over multi-path fading channels with multiuser receivers is presented. The basis of the analysis is the representation of the random signal-to-interference ratios (SIR) at finite system parameters in terms of the eigenvalues of the crosscorrelation matrices for which the non-asymptotic average distributions are found or known. The methodology presented complements the asymptotic limiting theory used in similar previous works [S. Verdu, S. Shamai, 1999, 2001 and R.R. Muller, 2000] over Gaussian/single-path fading channels, but at finite system parameters and over multipath fading channels. Though approach is non-asymptotic, it also validates asymptotically the predictions of the asymptotic limiting theory as the sizes of the system grow over all bounds. Application of the method is demonstrated by spectral efficiency derivations with linear multiuser receivers over multipath fading channels.