Conversion of Coordinate System in 3GPP Channel Model

Third generation partnership project (3GPP) provides channel models considering physical locations of transmitter and receiver. To represent physical values, two coordinate systems are utilized by 3GPP. One is the global coordinate system (GCS) that includes both transmitter and receiver and is the standard to describe line-of-sight (LOS) angle, distance, etc. The other is the local coordinate system (LCS) that is defined for each of transmitter or receiver and used to specify antenna pattern. As there are two coordinate systems, the conversion from one coordinate system to the other is required to compose the entire channel. In this paper, we provide a detailed and comprehensive explanations of the conversion for better understanding and insight.