MM-Wave LMDS/BFWA RF Modelling

A statistical model based on a detailed GIS LiDAR DEM (click here to see an example) representation of urban wireless channel topographies and the prediction of electromagnetic (EM) propagation in fixed point-to-point and point-to-multipoint (LMDS) wireless links operating at millimeter wavelengths (specifically targeting 28, 40, 60 & 80GHz bands) has been developed, with potential applications to the characterization, design and deployment of point-to-point and point-to-multi-point fixed wireless networks. The model uses realistic antenna radiation patterns. A specific goal of this model is the parameterization of the main physical attributes of the propagation mechanisms, which at millimeter waves predominantly incorporate scatter from building and ground surfaces, both non-uniformly illuminated by a directive transmitting antenna. The line-of-sight (LOS) received signal is presented in terms of universal probabilistic distribution functions (PDF) and quantified in terms of their first and second order moments. Building, rooftop and ground scatter are modelled using Physical Optics (PO) approximations which have been validated against filed measurements and experiments.

All data have been verified against field experimental measurements (see figure below). Average of accuracies achieved are within 5dB. Figure below shows the meshing and the predictions from surface contributions to the received signal power for a P2P 40GHz link in a 600×900m suburban area (Trefforest Industrial Estate near the University of Glamorgan). the model presents facilitates specific site planning and coverage calculations. The computing running time on a typical PC (i3/i5) computer depends on the resolution of the LiDAR used, the link range and the antenna’s beamwidth. For example, for a horizontal resolution of 5m, a P2P distance of 650m and a 20dBi antenna, the code takes no longer than 20 seconds (in Matlab) to run through all the triangulated surfaces. Where shadowing is implemented the running time is increased (this of course depends on many factors).

See a high-image resolution example here

Figure below shows predictions (with no shadowing) from a P2P 60GHz link in typical street canyon environment using 1m LiDar data resolution.

The model can also predict coverage, received power distributions and Rician K-factors. Progress is still ongoing in this model to include: shadowing, MIMO & capacity calculations and channel’s impulse response plus others typical parameters.

For more information, please contact Dr. Zaid Al-Daher

[1] Al-Daher, Z.; Ivrissimtzis, L.P.; Hammoudeh, A. “Electromagnetic Modelling of High Frequency Links with High Resolution Terrain Data”, IEEE Antennas and Wireless Propagation Letters, 10.1109/LAWP.2012.2226135, Oct 2012.

[2] Muhi-Eldeen, Z.; Ivrissimtzis, L.P.; Al-Nuaimi, M. “Modelling and Measurements of Millimetre Wavelength Propagation in Urban Environments”, Microwaves, Antennas & Propagation, IET, Volume: 4 , Issue: 9, Publication Year: 2010 , Page(s): 1300 – 13.

[3] Z. Muhi-Eldeen, L.P. Ivrissimtzis, M.O. Al-Nuaimi, “Measurements and Modelling of Cellular Interference in Local Point-to-Multipoint Distribution Systems”, Muhi-Eldeen, Z.; Ivrissimtzis, L.P.; Al-Nuaimi, M.O.; Microwaves, Antennas & Propagation, IET, Volume: 3 , Issue: 2, Publication Year: 2009 , Page(s): 250 – 259.