MIMO capacity of antenna arrays evaluated using radio channel measurements, reverberation chamber and radiation patterns

We compare different methods of evaluating arrays for multiple-input multiple-output (MIMO) systems through calculation of the MIMO capacity of a compact antenna array for mobile or WLAN applications at 1766 MHz and comparing it to a reference array of four mono- poles. Three different methods were used: evaluation using radiation patterns and a channel model, measurements in a reverberation chamber and simultaneous measurement of radio channel data using the two arrays. We conclude that all methods give very similar relative results and that the main difference in the two arrays is the 1.3 dB lower radiation efficiency of the compact array. The channel measurements also show that the arrays provide between 80% and 90% of the capacity of a 4 times 4 MIMO system.