MIMO Channel Capacity of a Measured Radio Channel for Outdoor Macro Cellular Systems at 3GHz-Band

Abstract

Multi-Input-Multi-Output (MIMO) is an emerging technology for the 4th-generation mobile communication systems due to the capability of high-speed data transmission. There have been only a few literatures regarding MIMO propagation characteristics under outdoor condition, and most of which have focused only on 2 GHz bands for existing cellular systems. However, since 3.4-3.6 GHz band will be allocated as one of frequency bands for the 4th-generation mobile communication systems, the channel characteristics at this band should be carefully considered. This report presents the outdoor MIMO channel characteristics measured by a 2×2 MIMO channel sounding system at the center frequency of 3.35 GHz in urban environment. In this measurement system, the 9-stage PN signals are transmitted by controlling the transmission timing in each transmitter, and hence, the complex MIMO channel impulse responses can be obtained by using same PN sequence in the receiver. From the measured MIMO channel characteristics, we computed the channel capacity based on each eigenvalue that was obtained through singular value decomposition (SVD). In addition, we evaluated the channel capacity for line-of-site (LOS) and non-line-of-site (NLOS) environments with respect to the antennas distance.