Multiple-input multiple-output (MIMO) radio channel measurements and experimental implementation for EDGE

In this paper we present results from the first field test to characterize the mobile multiple-input multiple-output (MIMO) radio channel. We measured the capacity, normalized to a single antenna system, and fading correlation between antennas of a system with 4 antennas on a laptop computer and 4 antennas at a rooftop base station. The field test results show that close to the theoretical 4 times the capacity of a single antenna system can be supported in a 30 kHz channel with dual-polarized, spatially-separated base station and terminal antennas under a variety of test runs, including suburban drives, highway drives, and pedestrian routes. Therefore, these results show that it may he possible to provide in excess of 1 Mbps in a 200 kHz mobile radio channel (for the 3G wireless TDMA system EDGE) with the appropriate base station antennas. To test the performance of MIMO for EDGE we have built a real-time experimental system with 2 transmitters and a 2-branch receiver. In this paper we describe the system implementation and present simulation results for 2/spl times/2 MIMO-EDGE showing only a 2 dB degradation due to channel estimation.