Hmm . . . I am having a mental block. I
think the channel characteristics function, H, is only determined when the xTU-C and xTU-R, at either end of the circuit, train-up. Hence an examination of plots of the logarithmic presentation of the channel characteristics function, Hlog, at different times
all post the same one discrete circuit train-up will be identical.
The two QLN plots you have shown are identical (I viewed them in full screen mode in a continuous cycle). My mental block continues . . .
The SNR plots show a definite hit in both the lower frequencies of the DS1 band and the lower frequencies of the DS2 band. Which is very peculiar.
![Undecided :-\](https://forum.kitz.co.uk/Smileys/kitzemotes/undecided.gif)
In the case of the DS1 band, it is almost as if the DSPBO is being increased (the "bad" plot) and then restored to normality (the "good" plot).
![hmmm :hmm:](https://forum.kitz.co.uk/Smileys/kitzemotes/hmmm.gif)