Time dynamic channel model for broadband fixed wireless access systems

Broadband fixed wireless access (BFWA) has been recognised as an effective first kilometre solution for delivering broadband services to residential and business customers. The large bandwidths available above 20 GHz make radio systems with very high capacities possible. Users can be offered bit rates in the order of several hundred Mbit/s. Such radio links can, in many cases, be an alternative to optical fibre in terms of capacity. This article presents a time dynamic channel model for BFWA operating above 20 GHz. The developed channel model represents the time varying wideband channel, and combines degradations due to multipath propagation, rain and vegetation attenuation as well as scintillation effects. A time varying tapped delay line model is employed to represent multipath propagation. Time dynamic rain attenuation is modelled using the Maseng-Bakken model. The vegetation attenuation is modelled by a NakagamiRice distribution with K-factor decreasing with wind speed. The short term probability density function of amplitude scintillation is modelled by a Gaussian distribution, while the long tem distribution is modelled using the Mousley-Vilar model. The combined channel model is suitable for simulating fading mitigation techniques such as adaptive coding and modulation, interference cancellation, and other capacity enhancing techniques.