Moving Virtual Array Measurement Scheme in High-Speed Railway

The moving virtual array measurement scheme, which means several adjacent samples from one single receiving antenna on a moving train or vehicle can be considered as the reception of multiple antennas, is proposed to overcome the difficulties of multiple-input-multiple-output (MIMO) channel measurement in high-speed railway scenario. This idea is similar to the virtual array measurement in static environment. Furthermore, the number of the equivalent elements in moving virtual array is derived by combining with the principle of switch multiplexed array scheme used in time-variant channel measurement. To verify this scheme, a 1X3 single-input-multiple-output (SIMO) channel sounder is built, and the measurements are carried out in a moving environment. The results show that moving virtual array scheme can reflect the spatial channel characteristics, especially in high signal-to-noise ratio (SNR) range. Finally, the applications of this scheme are discussed.