On Antenna Design Objectives and the Channel Capacity of MIMO Handsets

The branch correlation coefficient (BCC), the branch power ratio (BPR), and the total mean power (TMP) are often used to characterize the mobile multiple-input multiple-output (MIMO) channel. This work investigates to which degree these parameters are useful for maximizing the channel capacity of multiple-input multiple-output (MIMO) handheld devices used in data mode. A statistical point of view is applied, using about 2800 outdoor to indoor channel sounder measurements obtained with combinations of ten different handsets, four to eight test users, and a variety of different use cases (UCs). All measurements were made in an urban environment in a setup with two different base stations (BSs) and with the users inside a single building. For each measurement combination, the mean capacity (MC) and associated values of BCC, BPR, and TMP are obtained. From the data it is found that the MC is only weakly correlated with both the BCC and the BPR, while the MC is highly correlated with the TMP.