The eigenvalue densities of complex noncentral Wishart matrices are investigated to study an open problem in information theory. Specifically, the largest, smallest and joint eigenvalue densities of complex noncentral Wishart matrices are derived. These densities are expressed in terms of complex zonal polynomials and invariant polynomials. The connection between the complex Wishart matrix theory and information theory is given. This facilitates the evaluation of the most important information-theoretic measure, the so-called ergodic channel capacity. In particular, the capacity of multipleinput, multiple-output (MIMO) Rician distributed channels is investigated. We consider both spatially correlated and uncorrelated MIMO Rician channels and derive the exact and easily computable tight upper bound formulas for ergodic capacities. Numerical results are also given, which show how the channel correlation degrades the capacity of the communication system. Key words. complex random matrix, complex noncentral Wishart matrix, zonal polynomial, invariant polynomial, Rician distributed MIMO channel, ergodic channel capacity
AMS(MOS) subject classification. 94A15, 94A05, 60E05, 62H10To appear in Problems of Information Transmission.
RésuméOnétudie la densité des valeurs propres de matrices de Wishart noncentrales complexes en vue d'applicationsà un problème ouvert de la théorie de l'information. On obtient la densité conjointe de la plus grande et de la plus petite de ces valeurs propres au moyen de polynômes zonaux complexes et de polynômes invariants. Onétablie la relation entre ces matrices et la théorie de l'information pourévaluer la très importante capacité ergodique d'un canal. Onétudie la capacité des canaux riciens distribuésà entrées et sorties multiples (MIMO). On considère les canaux correlés et non correlés dans l'espace et l'on obtient facilement la borne supérieure exacte des capacités ergodiques. Les résul-tats numériques montrent que la corrélation du canal réduit la capacité du système de communication.