Frequency Selective Fading Model

From GNU Radio
Jump to navigation Jump to search

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

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 [1]
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 [2]


(R): Run-time adjustable

Num Sinusoids (SoS model)
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)
Noise seed
PDP Delays (samp)
Time delay in the fir filter (in samples) for each arriving WSSUS Ray
PDP Magnitudes
Magnitude corresponding to each WSSUS Ray (linear)
Num Taps
Number of FIR taps to use in selective fading model

Example Flowgraph[edit]

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[edit]

C++ files
Header files
Public header files
Block definition