Numerical Modeling of Indoor Propagation Using FDTD Method With Spatial Averaging

Abstract

The error in the local mean magnitude of the electric field (E-field), due to the numerical anisotropy, obtained by the finite-difference time-domain (FDTD) method is investigated. The spatial averaging is applied over a cube. In order to quantify the error, the numerical results are compared with theoretical and measured ones. The comparison between the FDTD method and theory is conducted for two empty rooms with perfect electric conductor (PEC) walls at 3 and 5 GHz. It is found that averaging over a cube with side length of 3.3 wavelengths (λ0) ensures a good matching between the local mean magnitude of the FDTD and theoretical E-field-maximum error below 23%, 95th percentile of the error below 6% and correlation above 0.83. Measurements over a cube at 3 GHz in empty and office environments are performed. The difference between the averaged numerical and measured magnitude of the E-field decreases with increasing the averaging stencil. For empty room the maximum error in the local mean FDTD results is 46% and for office scenario is 49% if the cube side length is 0.5λ0.

Wireless Energy Efficiency Evaluation for Buildings Under Design Based on Analysis of Interference Gain

“…Otherwise, if the distance from a small cell in the LOS/NLOS region is smaller than R L/N , the signal is considered as a detectable signal. The summation of all interference signals are defined as I B , which is computed by (14).…”

“…Traditionally, research on indoor wireless networks performance has focused on indoor propagation channel modelling [9]- [14], random blockage modelling [15]- [17], and line-of-sight (LOS) probability analysis [18]- [21], etc. Analysis on indoor network performances has therefore shed light on the impact of building structures on specific wireless networks performance.…”

Local Average Signal Strength Estimation for Indoor Multipath Propagation

“…In [25] the authors conducted simulations of the estimation of the electric field strength at 3 GHz and 5 GHz, using the FDTD method It was found that averaging over a 3D volume, a cube with a side length of 3.3λ, showed agreement between the local mean magnitude of the simulation and the theoretical electric field. Measurements and simulation were conducted at 3 GHz and it was found that as the averaging volume increased the error of estimating the electric field decreased.…”

Modeling of indoor network channels with dispersive media based on a modifiedCFDTDmethod

“…The FDTD is a full‐wave method for the spatial and temporal discretization of the differential Maxwell's equations 7 . Due to its wide applicability and simple programming, it has been applied to both narrowband and wideband indoor channel analysis 8–10 …”

“…7 Due to its wide applicability and simple programming, it has been applied to both narrowband and wideband indoor channel analysis. [8][9][10] The FDTD grid is based on Cartesian coordinate system, so there will be a large error due to the staircase approximation when dealing with curved objects. In order to reduce the staircase error, several hybrid subgridding techniques have been proposed in reference 11-13, but it is difficult to eliminate the reflection between cell boundaries by using these methods.…”