Measurements and modelling of millimeter-wave channel at 28 GHz in the indoor complex environment for 5G radio systems

This paper presents an experimental characterization of millimeter wave (mmWave) wireless channel at 28 GHz for fifth generation (5G) millimeter wave wireless communication systems. The propagation characteristics of mmWave signal in the complex indoor radio channels are discussed based on the extensive measurement and based on the method of shooting and bouncing ray tracing/image (SBR/IM). Received power, omnidirectional path loss models, and root-mean-square (RMS) delay spreads statistics are analyzed. A good agreement is achieved between measured results and simulated results, so a method for synthesizing the omnidirectional antenna pattern and resulting omnidirectional received power from empirical data using directional horn antenna by summing the received powers from each angle combination has been validated. The cumulative distribution function (CDF) of received power can be described by the log-normal distribution. Moreover, the path loss exponent (PLE) values vary between 1.67 and 1.77. The Gaussian distribution models best fit the RMS delay spreads at 28 GHz.