Indoor Office Wideband Millimeter-Wave Propagation Measurements and Channel Models at 28 GHz and 73 GHz for Ultra-Dense 5G Wireless Networks (original) (raw)

This report provides the world's first comprehensive study of indoor channels at 28 GHz and 73 GHz using different antenna polarizations and combined polarizations to generate large-scale path loss models and time delay spreads for the development of 5G standards at 28 GHz and 73 GHz. Directional and omnidirectional path loss models and directional multipath RMS delay spread values are presented, yielding insight into mmWave indoor office propagation characteristics. The results show that novel large-scale path loss models provided here are simpler and more physically-based compared to previous 3GPP and ITU indoor propagation models that require more model parameters, yet offer very little additional accuracy and lack physical basis. The closed-form expressions that optimize existing and newly proposed largescale path loss models are given in Appendix A, the raw omnidirectional data used to create the large-scale path loss models in this report are tabulated in Appendix B, and standard deviations of each large-scale path loss model are tabulated for side-by-side comparison in Appendix C. The technical report describes the extensive ultra-wideband millimeter-wave indoor propagation measurement campaign conducted at 28 GHz and 73 GHz by the NYU WIRELESS research team during the summer of 2014. The measurements were sponsored by the NYU WIRELESS Industrial Affiliates Program and the National Science Foundation. Measurements were performed using two similar 400 Mega-chips-per-second sliding correlator channel sounder systems with mechanically-steerable, highly-directional 15 dBi (at 28 GHz) and 20 dBi (at 73 GHz) horn antennas at both the transmitter and receiver, with the transmitter antennas always vertically polarized and the receiver antennas vertically and horizontally polarized to measure co-and cross-polarized channel characteristics. The indoor measurements were conducted in a typical office environment on the 9th floor of 2 MetroTech Center, Brooklyn, NY. Transmit antennas were set at a height of 2.5 meters near the ceiling (typical indoor wireless access point heights), and receiver antennas were placed at heights of 1.5 meters (typical handset heights), to emulate a typical WLAN environment. Five transmitter (TX) locations and 33 receiver (RX) locations were chosen and a total of 48 TX-RX location combinations were measured (identical locations at both frequencies) in a typical office environment to investigate the complex indoor propagation channel. The measurement environment was a closed-plan in-building scenario that included line-of-sight and non-lineof-sight corridor, hallway, cubicle-farm, and adjacent-room communication links. A corridor environment is when a propagating signal travels down a corridor to reach the receiver by a line-of-sight path, reflections, and/or diffraction, but not penetration. An cubicle-farm environment includes a large layout and a central TX location, where the propagating signal reaches the receiver by a line-of-sight path, reflections, and/or diffraction, but not penetration. A closed-plan environment is when a propagating signal penetrates an obstruction to reach the receiver in addition to potential reflections, and/or diffraction. All measurement environment scenarios are included as part of the closed-plan environment, and the models in this report are for closed-plan and thus include all locations measured (both line-of-sight and non-line-of-sight). Power delay profiles were acquired at unique antenna pointing angles for each TX-RX location combination for distances that ranged from 3.9 m to 45.9 m for both frequencies, with-6.5 dBm to 24 dBm of transmit power at 28 GHz and-7.9 dBm to 12.3 dBm of transmit power at 73 GHz. Six angle of arrival (AOA) antenna sweeps and two angle of departure (AOD) antenna sweeps were conducted in the azimuth plane at fixed elevation planes for each TX and RX location combination using highly-directional and steerable horn antennas for verticalto-vertical (V-V) antenna polarizations. Six identical AOA and two identical AOD antenna