Efficient Sum-of-Sinusoids based Spatial Consistency for the 3GPP New-Radio Channel Model

Spatial consistency was proposed in the 3GPP TR 38.901 channel model to ensure that closely spaced mobile terminals have similar channels. Future extensions of this model might incorporate mobility at both ends of the link. This requires that all random variables in the model must be correlated in 3 (single-mobility) and up to 6 spatial dimensions (dual-mobility). Existing filtering methods cannot be used due to the large requirements of memory and computing time. The sum-of-sinusoids model promises to be an efficient solution. To use it in the 3GPP channel model, we extended the existing model to a higher number of spatial dimensions and propose a new method to calculate the sinusoid coefficients in order to control the shape of the autocorrelation function. The proposed method shows good results for 2, 3, and 6 dimensions and achieves a four times better approximation accuracy compared to the existing model. This provides a very efficient implementation of the 3GPP proposal and enables the simulation of many communication scenarios that were thought to be impossible to realize with geometry-based stochastic channel models

An explicit ground reflection model for mm-wave channels

5G mobile communication systems are likely to use the enormous bandwidths available at mm-wave frequencies. However, there is an important propagation effect that can have a major impact on the performance - the ground reflection (GR). This effect is currently not sufficiently covered by existing 3GPP propagation models. The GR causes fading both on the small-scale level, e.g., multi-path fading, and on the large-scale level, e.g., path loss and shadow fading. However, the small-scale effects become more dominant at mm-wave frequencies. This paper presents a method to explicitly include the GR in geometry-based stochastic channel models. First, an improved small-scale fading model is proposed that covers the influence of the GR on the delay and angular spreads as well as on the polarization. Second, the influence of the electromagnetic properties of the ground is discussed. Third, the path loss and shadow fading models are adjusted to accommodate the large-scale effects of the GR. The updated model allows taking GR fading into account when designing new radio communication systems and evaluate the performance before the standardization, prototyping and product development phase

Satellite and terrestrial multi-connectivity for 5G: making spectrum sharing possible

International audienceThis paper reports the first results of the 5G-ALLSTAR project [1] aiming at providing solutions and enablers for spectrum sharing in a 5G cellular and satellite multi-connectivity context. First, we present an exhaustive study of the frequency bands eligible for these systems in the short and medium term. A ray-tracing based and a geometry-based stochastic channel models developed in the project are then described. These models can be used to simulate systems involving terrestrial and non-terrestrial networks. We then describe three different ways investigated in the project for managing interference: signal processing (hardware implementation of a 5G New Radio compatible physical layer), beamforming (steering and switching beams in order to avoid the interference while preserving the spectral efficiency) and radio resource management (tool designed for joint optimization of satellite and terrestrial resource sharing)