Statistical mechanics of CDMA multiuser demodulation

I investigate the multiuser demodulation problem which arises in code-division multiple-access (CDMA) systems. The relationship between the multiuser demodulation problem and a variant of the Hopfield model is established, based on which the replica analysis of some multiuser demodulation schemes is performed. Analytical results are presented for the maximum-a-posteriori (MAP) demodulation, the optimal demodulation, and the naive mean-field approximation to the optimal demodulation.