Statistical Mechanical Analysis of CDMA Multiuser Detectors
Tatsuya Uezu, Mika Yoshida, Toshiyuki Tanaka, Masato Okada · Progress of Theoretical Physics Supplement · 2005
A class of code-division multiple-access (CDMA) multiuser detectors in the large-system limit has been investigated by Tanaka by means of statistical mechanics, i.e. the replica method. He evaluated analytically the bit-error rate, the multiuser efficiency, etc. of Marginal-Posterior-Mode (MPM) detectors under the replica symmetry (RS) ansatz. In this paper, to investigate the breaking of the replica symmetry, we study the de Almeida-Thouless (AT) stability, the entropy, and the free energy of the RS solutions for MPM detectors including individually optimum (IO) ones.