[linux-dvb] [patch] Improvement dvb-s2 lock with KNC1 DVB-S2 Plus, Satelco DVB-S2, TT S2 3200, Technisat DVB-S2

jlacvdr jlacvdr at gmail.com
Wed Oct 10 13:49:52 CEST 2007


> >> +    reg = STB0899_READ_S2REG( STB0899_S2DEMOD, DMD_CNTRL2 );
> >> +    STB0899_SETFIELD_VAL( SPECTRUM_INVERT, reg, 1 );
> >> +    stb0899_write_s2reg( state, STB0899_S2DEMOD, STB0899_BASE_DMD_CNTRL2, STB0899_OFF0_DMD_CNTRL2, reg );
> >>
> >>
> >>
> >> Why do you forcefully invert the I/Q inputs ? Different hardware have different configurations.
> >
> > yes, there are different hardware configurations, so with this patch
> > the algo find automatically the good configuration.
> > This is an initialiation, I begin with a I/Q configuration, if failure
> > the configuration is inverted.
>
>
> Q) Does it work for you, if you started with SWAP_OFF, rather than SWAP_ON,
> retaining your logic. Or do you see any other issues/degradation when you change
> the initial INVERSION state ?
>
> Currently there will be a case of inversion in your logic, but for the hardware that we
> have and given the networks, the chances of finding an inversion is much less. Can
> you please check whether INVERSION_OFF in the initial case does work better still, if
> not worser ?
>

Hi,

I do the test : trying 100 zap ( 47 on dvb-s, 53 on dvb-s2 ) with
zsap2 on the card KNC1
if I start with SWAP_OFF:  I obtain 97 lock successfully
if I start with SWAP_ON:  I obtain 99 lock successfully
the failures are not on the same transponder.

So, I think the initial state doesn't have influence on the result.

Regards,

 JLac



More information about the linux-dvb mailing list