28GHz millimeter wave propagation models based on ray-tracing in urban scenario

The millimeter wave spectrum is widely studied as one of the most important resources for the IMT (International Mobile Telecommunication) system towards to the 5G for the large bandwidth. In this paper, its investigated the propagation characteristics of 28GHz millimeter wave using Ray-Tracing in Chengdu city of China. Both the close-in-reference and floating intercept path loss fitting methods combining with the shadow fading are studied. Based on the Ray-Tracing, different path loss fitting method combining different antenna pattern and outage threshold are studied. According to observation of the comparison with these two fitting path loss methods, it is found that close-in-reference method can get more robust attenuation exponent. In addition, its shadow fading deviation will be less than floating intercept method in shorter transmit distance, and only increase less than 2dB for longer transmit distance. A certain amount of outage receiver point are found and the influence to path loss are analyzed. For the high direction antenna pattern, if it can not capture the strong path, it will also influence the path loss results.