Synchronous channel sounder using horn antenna and indoor measurements on 28 GHz

The millimeter wave band will be a key component in the next generation wireless communication system (5G), and a proper channel model is needed for developing the future 5G cellular technologies. This paper introduces a 28 GHz channel sounder based on automatically rotating horn antennas with time synchronization ability between the transmitter (TX) and the receiver (RX). We have developed a sounding method for synchronized measurement using the proposed channel sounder system which records time-stamping to measure the relative propagation time from the transmitter to receiver. The proposed approach allows us to generate an omni-like channel measurements by synthesizing all directional measurements, which have been verified by comparison with the measurements of omni-directional antennas. Subsequently, the omni-directional propagation measurement results are provided in an in-building environment similar to a small shopping mall. From the measurements, the clustering analysis has been done including its power distribution. This paper provides the first channel sounder and initial results to obtain the synthesized omni-directional results in millimeter wave 28 GHz band.