MIMO Channel Capacity for Handsets in Data Mode Operation

The current paper concerns realistic evaluation ofthe capacity of the MIMO channel between a BS and handhelddevice, such as a PDA or smart phone, held in front of theuser’s body (data mode). The work is based on measurementsof the MIMO channel between two widely separated BSs in amicro-cellular setup, and seven handsets located in an indoorenvironment. The measurements are done simultaneously in boththe 776 MHz and 2300 MHz bands, and from the two BSs. Thehandsets are realistic types and were measured both in free spaceand with twelve different users, using both one and two hands.The random capacity of the channels are evaluated in termsof percentiles. For an SNR of 10 dB, median capacities in freespace of about 4.4–4.7 bit/s/Hz for the low band and about 3.3–3.8 bit/s/Hz for the high band were found. The mean decrease incapacity due to the user was found to be up to about 2.2 bit/s/Hz,depending on the band and handset. More results are presentedin the paper.