Frequency Selective Fading Model2

This block implements a basic fading model simulator that can be used to help evaluate, design, and test various signals, waveforms, and algorithms.

References

The flat-fading portion of the algorithm implements the following

      Compact Rayleigh and Rician fading simulator based on random walk processes
      A. Alimohammad S.F. Fard B.F. Cockburn C. Schlegel
      26th November 2008

(Algorithm III with a novel addition of time delay tap random walk )

The frequency selective extension of the block roughly implements

      A Low-Complexity Hardware Implementation of Discrete-Time
      Frequency-Selective Rayleigh Fading Channels
      F. Ren and Y. Zheng
      24-27 May 2009

Parameters

(R): Run-time adjustable

Num Sinusoids (Stochastic SoS model + delay drift)

Number of sinusoids used to simulate gain on each ray

Normalized Max Doppler (fD*Ts) (R)

Normalized maximum doppler frequency (f_doppler / f_samprate)

LOS Model

LOS path exists? chooses Rician (LOS) vs Rayleigh (NLOS) model.

Rician factor (K) (R)

Rician factor (ratio of the specular power to the scattered power)

Seed

Noise seed

PDP Delays (samp)

Time delay in the fir filter (in samples) for each arriving Wide-Sense Stationary Uncorrelated Scattering (WSSUS) Ray

PDP Delay StdDev (per samp)

A vector of values that specify the gaussian step size std of delays

PDP Delay Max-Dev (per samp)

A vector of values that specify the max deviation of each delay component

PDP Magnitudes

Magnitude corresponding to each WSSUS Ray

Num Taps

Number of FIR taps to use in selective fading model

Example Flowgraph

Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI. Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately. The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.

Source Files

C++ files

[1]

Header files

[2]

Public header files

[3]

Block definition

[4]