Could you please help me how i can generate an independent sample fast fading from Rayleigh distribution (NLOS) and the Rician distribution (LOS), I can the correlation in time due to mobility and also the correlation in frequency due to the multipath delay profile. i just need to get a statistically reasonable fading model.
and some information about Jakes model.
Thank you
Using Communications System Toolbox™ you can implement fading channels using objects or blocks. Rayleigh and Rician fading channels are useful models of real-world phenomena in wireless communications. These phenomena include multipath scattering effects, time dispersion, and Doppler shifts that arise from relative motion between the transmitter and receiver. This section gives a brief overview of fading channels and describes how to implement them using the toolbox.
The major paths result in the arrival of delayed versions of the signal at the receiver. In addition, the radio signal undergoes scattering on a local scale for each major path. Such local scattering is typically characterized by a large number of reflections by objects near the mobile. These irresolvable components combine at the receiver and give rise to the phenomenon known as multipath fading. Due to this phenomenon, each major path behaves as a discrete fading path. Typically, the fading process is characterized by a Rayleigh distribution for a nonline-of-sight path and a Rician distribution for a line-of-sight path.
The relative motion between the transmitter and receiver causes Doppler shifts. Local scattering typically comes from many angles around the mobile. This scenario causes a range of Doppler shifts, known as the Doppler spectrum. The maximum Doppler shift corresponds to the local scattering components whose direction exactly opposes the mobile's trajectory.
Implement Fading Channel Using an Object
> A baseband channel model for multipath propagation scenarios that you implement using objects includes:
> N discrete fading paths, each with its own delay and average power gain. A channel for which N = 1 is called a frequency-flat fading channel. A channel for which N > 1 is experienced as afrequency-selective fading channel by a signal of sufficiently wide bandwidth.
A Rayleigh or Rician model for each path.
Default channel path modeling using a Jakes Doppler spectrum, with a maximum Doppler shift that can be specified. Other types of Doppler spectra allowed (identical or different for all paths) include: flat, restricted Jakes, asymmetrical Jakes, Gaussian, bi-Gaussian, and rounded.
If the maximum Doppler shift is set to 0 or omitted during the construction of a channel object, then the object models the channel as static (i.e., fading does not evolve with time), and the Doppler spectrum specified has no effect on the fading process.
I HOPE THIS WOULD HELP YOU OUT IN SOME WAYS..
REGARDS
BHUWAM
You can use the attached MATLAB which is supported by the ns-3 developers for simulating small scale fading in LTE according to the 3GPP documentations:https://www.nsnam.org/docs/release/3.21/models/html/lte-user.html
https://www.nsnam.org/docs/release/3.21/models/html/lte-user.html
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