Measurement-based Channel Characteristic Analysis with Different Antenna Heights at 3.7 GHz

Channel measurement is the most direct and accurate method to analyze the characteristics of wireless channel. In this paper, four channel measurements with different transmitter antenna (Tx) heights of 2 m, 3 m, 5.5 m and 8 m were conducted in an urban micro-cell (UMi) scenario at 3.7 GHz. The measurements include line-of-sight (LOS) and non-line-of-sight (NLOS) propagation. The transmitter of the measuring system consisting of a vector signal transceiver (VST), a high speed switch, a power amplifier (PA) and a planar antenna array (PLA). While the receiver is composed of a VST, a high speed switch, a low noise amplifier (LNA) and a uniform circular antenna array (UCA). Statistical results and comparative analysis are presented, including power delay profiles (PDPs), pathloss (PL), root mean square (RMS) delay spread (DS), elevation/azimuth of arrival (EOA/AOA) and corresponding elevation/azimuth RMS spread of arrival (ESA/ASA). The alpha-beta-gamma (ABG) model and close-in (CI) free space reference distance model are adopted. We use multiple signal classification (MUSIC) algorithm to estimate the EOA /AOA of the channel and analyzed the variation of relevant EAS/ASA. It can be seen from the results that the pathloss exponent decreases with the increasing of the Rx heights. The delay spread, on the contrary, increases as the antenna heights increase. The ASA decreases with the antenna goes higher and ESA has an opposite trend.