Asymptotic Mutual Information for Rician MIMO-MA Channels with Arbitrary Inputs: A Replica Analysis

Using the replica method, originally developed in statistical physics, we derive the asymptotic mutual information (MI) of a spatially correlated Rician multiple-input multiple-output (MIMO) multiple-access (MA) channel for any given signaling input distributions (not necessarily Gaussian) in the large-system regime where the numbers of antennas at the transmitters and the receiver go to infinity with a constant ratio. In addition to the result that uses joint optimum decoding (JOD) at the central receiver, we also obtain asymptotic characteristics of a more practical system which performs separate detection and decoding (SDD) (i.e., spatial detection followed by a temporal error-correction decoder). Simulation results reveal that the asymptotic results provide promising estimates for the average performance metrics (e.g., the error probability and the MI) even with only a few antenna elements at the transceivers.