Outdoor Large Scale Propagation Measurements And Channel Models Analysis At Low And High Frequencies For 5G Wireless Networks

The transmission rate and quality of the communication systems are restricted by the wireless channel. In order to adopt appropriate physical layer technologies the characteristics of wireless channel must be fully understood. Inproving transmission quality may be a challenge to the wireless communication systems, but the problem of signal coverage is more urgent to solve. Based on the spectrum requirement of the next generation wireless communication, the thesis studies the propagation characteristics of the fourth generation mobile communication candidate frequency band 3.5GHz and the next generation communication candidate frequency band 28GHz and 39GHz channel. The analysis results are of great significance to the deployment of 5G networks.Based on the existing narrowband and broadband measurement schemes, a narrowband channel measurement scheme is proposed for the research of outdoor propagation model. Besides, a set of measurement system with high accuracy and utility is designed. Then we focused on the research of the city's macro-cellular area, NLOS environment.Based on the theory of free space propagation, the measurement data are analyzed by CI path loss model and FI path loss model. For each set of data, the path loss exponent n, the shadow fading variance ?CI of the CI path loss model is obtained. The intercept ?, the slope ? and the shadow fading variance ?FI of the FI path loss model are also obtained. In addition, the FI path loss model is compared with the 3GPP 36.873 and 38.900 path loss models to quantify the difference between the 3GPP model and the specific environmental path loss in China.This thesis summed up conclusions for 3.5/28/39GHz propagation model as follows: (1) With the frequency increases, the path loss is increasing. (2) When the receiver antenna height increases within a certain range, it can reduce the path loss. (3) The environment has greater impact on the high-frequency signal than the low frequency signal. (4) 3GPP UMa NLOS path loss models can no longer be applicated to special environment.