Radiation efficiency, correlation, diversity gain and capacity of a six-monopole antenna array for a MIMO system: theory, simulation and measurement in reverberation chamber

A six-monopole circular antenna array for use in a MIMO system is considered. The authors show how to calculate the embedded element patterns, both by classical analytical modeling and by the method of moments. Thereafter, these are used to calculate the radiation efficiency of each embedded element, correlation and diversity gain, as well as the maximum average capacity of the MIMO system when the array is located in a rich scattering environment. The theoretical value for the capacity is obtained by numerically distributing many plane wave sources statistically uniformly over 4π, letting them illuminate the calculated embedded element pattern and using Shannon´s capacity formula on the received wave amplitudes. The calculated results are compared with measurement in a reverberation chamber, representing a similar scattering environment. The agreement is good.