A 24/60-GHz Dual-Band Double-Directional Channel Sounder Using COTS Phased Arrays

The use of millimeter-wave (mm-wave) bands has been expanding in new wireless communication systems such as fifth-generation (5G) mobile systems and WiGig WLANs. Since mm-waves have quasi-optical propagation characteristics, it is necessary to develop a channel model that can cover site-specific characteristics of various environments. For this reason, a large amount of channel measurement data measured in a wide range of frequency bands covering mm-wave in various environments should still be required. In particular, it is necessary to obtain the angular channel characteristics on both sides of the transmitter and receiver, but this requires considerable time and cost. The authors' previous study developed a 60-GHz double-directional (D-D) channel sounder using commercial-off-the-shelf (COTS) phased-array beamforming RFs, and it has currently been extended to realize 24/60-GHz dual-band simultaneous measurement. In this paper, we detailed the design of the dual-band D-D channel sounder. As a demonstration of the operation, some measurement results taken in typical urban macro-cell (UMa)/micro-cell (UMi) scenarios were quickly reported.