Besides, the DSP workload happens in the DSP (Sharc) processors, not
the Dragonball control processor. So, fancy filtering, NR, etc.
should not impact the user control response, at least to first order.
The sweep is the only function where actual receive data (from DSP
land) ends up on the LCD (via Dragonball), apart from the SubRx
S-meter.
If you measure the receiver delay, you will see the effect of changing
the DSP "workload" as you change the number of filter taps. This
delay is one factor limiting QSK performance, for example. My tests
on the Orion (1.372) show the delay is 14 ms at 199 taps, and 8 ms at
32 taps for CW and SSB modes.
There should be a lot of unused Dragonball CPU power on the O 2,
especially, that could be used for signal analysis, modulation
monitors, and what have you. All you need is software developer time
-- but that's a scarce commodity. (Another argument for an open source
development program?)
73 Martin AA6E
On 3/17/06, Sinisa Hristov <shristov@ptt.yu> wrote:
> Lin Davis wrote:
>
> > Interesting! I wonder if Ten-Tec did this to reduce the DSP workload thus
> > increasing overall performance (i.e.. sweep, and user input response). If I
> > understand correctly, if you cut the bandwidth that a DSP filter must
> > contend
> > with by 2, you cut the "work load" by four;
>
> The workload is proportional to filter length (199 taps default),
> and not related directly to the bandwidth.
>
>
> > the filter requires half the coefficients
>
> The number of coefficients is most dependent on the
> required filter slope, measured in dB/Hz. As the filter
> gets narrower, the tendency is for the number of
> coefficients to grow, with sampling rate unchanged.
>
>
> > and since the sampling rate can be cut in half as well, (decimation is the
> > term)
>
> My understanding is that Orion uses no BW-dependent decimation.
>
>
> 73,
>
> Sinisa YT1NT, VE3EA
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
--
martin.ewing@gmail.com - Ask me if you'd like a free Google Mail account
http://blog.aa6e.net
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|