Capacity evaluation of MIMO communication systems with channel matrix estimation error and the presence of scatterers

Statement of the problem. In modern wireless systems, especially those based on 5G/6G and Internet of Things (IoT) technologies, the efficiency of MIMO systems decreases in environments with intense signal scattering. Multipath propagation with non-line of sight, including single and double reflections, causes interference, fading, and channel matrix estimation errors, which reduce capacity and communication reliability. The development of a communication channel model in the presence of scatterers, methods for estimating the channel matrix taking into account multiple reflections, and analysis of MIMO efficiency in such conditions are relevant scientific problems. The purpose of the work. Study of a method for estimating a channel matrix based on a three-dimensional geometric model for conditions of multipath signal propagation and the presence of estimation errors, as well as subsequent analysis of the influence of matrix estimation errors on the capacity of a MIMO communication system. Results. Mathematical models of the channel matrix have been developed that take into account single and double reflections, as well as the distribution of scatterers according to the von Mises–Fisher distribution. An analysis of ergodic capacity has been performed depending on the level of estimation errors, the number of antennas, the Rice coefficient, the degree of scatterer concentration, and the distance between antennas. Practical significance and scope of application. The results obtained are of practical significance for the design and optimization of MIMO systems in conditions of intense scattering at objects in the communication channel, especially when deploying modern 5G/6G wireless networks in environments with uncontrolled reflections.