A Flexible Millimeter-Wave Radio Channel Emulator Design With Experimental Validations

Abstract

Abstract-Millimeter wave (mmWave) channel emulator (CE) is an essential tool for air interface testing of the upcoming mmWave communication systems. A flexible CE, which is capable of frequency setting from sub-6 GHz to mmWave bands and flexible system bandwidth setting, is highly desirable. This is due to the fact that potential frequency bands and system bandwidths are undecided for mmWave systems and it is likely that multibands with scalable system bandwidths will be supported. In this paper, a frequency extension scheme based on frequency up-anddown conversion, and a novel bandwidth enhancement scheme based on the band-combining principle, are proposed to upgrade existing sub-6GHz CE to meet the requirements in the mmWave CE design. The designed mmWave CE is experimentally validated, where the measured Doppler and delay profiles agree well with the target ones. Moreover, the beamforming validation measurements showed that excellent gain and phase control of the mmWave CE output ports can be realized.

Artificial Intelligence Enabled Radio Propagation for Communications—Part I: Channel Characterization and Antenna-Channel Optimization

“…: ML-based parameter extraction algorithms need a huge amount of real channel measurement data. Therefore, the design of channelsounder [76] and channel measurement campaign will play an important role in future ML-based algorithms. However, it is expensive and time-consuming to carry out channel measurement in various environments, which will become the bottleneck of novel algorithms -this is especially true for mmWave and THz bands, and high-mobility scenarios such as aircrafts and trains.…”

Low‐altitude UAV air‐ground propagation channel measurement and analysis in a suburban environment at 3.9 GHz

“…RMS delay spreads are fundamental parameters of small-scale fading for AG channels, as this parameter is commonly used to quantify the time dispersion. The calculation of RMS delay spread is expressed in (8). Here, we use a threshold to remove the noise.…”

“…Propagation characteristics of UAV AG channels for low altitudes (<120 m) are significantly different from the channels in conventional terrestrial cellular and vehicular networks, especially in terms of the time and frequency selectivity and the associated fading statistics [7,8]. In cellular channels, most receivers (Rx) are low-speed, and in non-line of sight (NLOS) conditions, there are many scatterers distributed on the ground within the local communication environment [9].…”

Design and implementation of a wideband channel emulation platform for 5G mmWave vehicular communication

“…Some preliminary investigations for this work have been published in [25]. The band‐combining principle proposed in [26] and simulated in [27] are both examples of baseband channel stitching, which requires two‐stages of up and down conversions and further post‐processing for the intended channel models. However, the proposed band stitching method in this paper is developed over the intermediate frequency with one‐stage of up and down conversions, which reduces system complexity and offers a direct interface to the baseband signals from the modem under test.…”