GnuRadio: Clock Recovery MM: imu out of bounds I have created a flowgraph, based on an example of Michael Ossmann, which takes in a signal, and should output bits. 

I need to use the clock recovery MM block, which I do not fully understand yet. However, after reading some blogposts, I am quite sure that I can leave most of the settings default, except for the Omega one. Here's my flowgraph:



When running this flowgraph, it gives me the following error:

thread[thread-per-block[5]:&lt;block clock_recovery_mm_ff (9)&gt;]: mmse_fir_interpolator_ff: imu out of bounds.


While searching, I stumbled upon this piece of code in the source of GnuRadio:

int imu = (int)rint(mu * NSTEPS);   
  if((imu &lt; 0) || (imu &gt; NSTEPS)) { 
    throw std::runtime_error("mmse_fir_interpolator_ff: imu out of bounds.\n"); 
  }


So, I suspect it is not due to my Omega setting (which might be wrong, I have to play with that setting), but that it is due to my Mu setting, which is just the default (0.5). However, I understand that Mu needs to be between 0 and 1, so I do not really understand what the problem is. Anyone who does?

Environment details:


GNU Radio Companion 3.7.7.1
Running a GNU Radio live DVD in a virtual machine (VirtualBox 4.2.12) on Windows 7.
Using Volk machine: ssse3_64
The M&amp;M clock recovery block has a bug in it, such that it can't reliably handle more than 8 samples per symbol without inadvertently dropping samples.  That interpolating resampler alignment bug may also be responsible for generating mu values outside of [0.0, 1.0].

I'd strongly recommend, downsampling the input from 2.5ksamples/symbol down to 6 or 8 samples /symbol before the M&amp;M block.