readme.x11

Linmodem is soft modem source code for embedded system

Linmodem contains an X11 interface which can be used to monitor the
modem parameters. It is used for example in v34 testing (lm -m v34). The
X11 simulation works only in 16 bit mode. If you are interested by
other screen depths, please implement them :-)

The function keys are used to change the parameters which are dumped
on the screen:

* for V34:

F1 : dump the brut samples which enter into the modem (at 8000Hz). A
hamming windowed FFT is done to output the spectral power.

F2 : dump the echo cancellor parameters (not implemented yet).

F3 : dump the samples after frequency normalization & symbol timing
recovery. You have 3 samples per baud for V34. A hamming windowed FFT
is done to output the spectral power.

F4 : dump the equalizer filter in both time & frequency domains.

F5 : dump the QAM points just after the equalizer and phase
recovery. This graphic can be used to monitor the overall modem
quality.


* for V21/V23 tests

F1: same as V34

F3: decision samples