Design and calibration of a double-directional 60 GHz channel sounder for multipath component tracking

The 60 GHz band is being considered for many high-bandwidth wireless applications. To support standards development for these applications, NIST has developed an untethered 60 GHz, 8×16 MIMO channel sounder. It employs a pseudorandom bit sequence with a bandwidth of 4 GHz. The sounder can precisely measure radio propagation channel characteristics such as path loss, small-scale fading, delay dispersion, absolute delay, angle-of-arrival (AoA), angle-of-departure (AoD), and Doppler power spectrum. Its ability to measure the time dynamics of the millimeter-wave radio channel, when untethered and in motion, is unique. It employs electronically-switched MIMO antenna arrays, a robot for moving measurements and an automated one-dimensional positioner for precision measurements at fixed locations. Sounder performance is improved by use of pre-distortion filters and precision calibration of the RF and timing systems. Data showing initial AoD and AoA estimation error are presented along with initial test results for ground-plane reflection.