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This paper discusses over the air (OTA) testing for multiple input multiple output (MIMO) capable terminals with emphasis on channel spatial characteristics emulation. A novel technique to obtain optimum power weights for the OTA probes based on convex optimization is proposed. The proposed technique emulates spatial correlation as well as introduces constraints on the maximum deviation between the target power azimuth spectrum (PAS) and the emulated PAS in terms of mean angle of arrival (AoA) and azimuth spread (AS). Simulation results show that the proposed emulation technique present better performance compared with existing techniques in the literature. This improvement is further demonstrated by measurement results in a practical MIMO OTA setup.

Based on a recent study of the ways a phone is held (a grip study), CAD models of the human hand have been generated, and antenna proximity effects for both talk and data modes in mobile phones have been investigated using an FDTD code. The simulation results showed that the hand, and especially the index finger, exhibited a major contribution in determining the total loss when compared to the upper torso alone. The influence of the position of the fingers on the handset was found to be more important when close to the antenna. The palm-handset gap and the index-finger location were the main factors for both absorption and mismatch loss. Different data-mode hand phantoms and configurations were investigated, showing that both "overlapped" and "interlaced" grip styles similarly influenced the antenna's communication performance.

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