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Sent: Friday, March 18, 2005 2:34 AM
To: Robert McGwier
Cc: [EMAIL PROTECTED] Org
Subject: RE: [Discuss-gnuradio] signals/atsc question
Quoting Robert McGwier <[EMAIL PROTECTED]>:
> I would like to do N, where N is larger than 4, correlators on the FPGA
> in order to do code acquisit
Quoting Robert McGwier <[EMAIL PROTECTED]>:
> I would like to do N, where N is larger than 4, correlators on the FPGA
> in order to do code acquisition for code division multiplexing. I would
> also
> like to do beam steering experiments on four channels. All involve
> multiplications and the lo
At 01:38 AM 3/16/2005 +, you wrote:
We are not anywhere near the fill up point in the Cyclone yet
are we?
Bob
Good question - according to the compilation report of a recent production
version,
27% of memory is used in 2 16bit 2K FIFO's:
-8<
Flow Status Suc
On Wed, Mar 16, 2005 at 01:38:50AM -, Robert McGwier wrote:
> I would like to do N, where N is larger than 4, correlators on the FPGA
> in order to do code acquisition for code division multiplexing. I would
> also
> like to do beam steering experiments on four channels. All involve
> multipl
scuss-gnuradio] signals/atsc question
> Altera has a nice app note on synthesizing multipliers by burning up
> RAM. As I recall it's not too hard to generate a multiplier that does
> 12-bit*16-bit in two cycles. We're clocked at 64 MHz, though 128 MHz
> should be possible with
> Altera has a nice app note on synthesizing multipliers by burning up
> RAM. As I recall it's not too hard to generate a multiplier that does
> 12-bit*16-bit in two cycles. We're clocked at 64 MHz, though 128 MHz
> should be possible with some hacking.
>
> If you're decimated down to 8MS/s comp
So, for a theoretical USB bandwidth of 32Mbyte/sec, that's
128Msamples/sec coming from the A/D :-)
Eric Blossom wrote:
On Wed, Mar 02, 2005 at 09:59:34AM -0500, Marcus Leech wrote:
Sample-size reduction, in order to increase effective bandwidth up to the
computer, would be of great benefit for
On Wed, Mar 02, 2005 at 09:59:34AM -0500, Marcus Leech wrote:
>
> Sample-size reduction, in order to increase effective bandwidth up to the
> computer, would be of great benefit for radio astronomy work. The
> big observatories that are sampling many hundreds of Mhz at a time
> typically use d
John Gilmore wrote:
But even at 20 Ms/s, with 14-bit samples passed in 2-byte shorts,
we've exceeded the capacity of the USB bus. It would be pretty easy
to build a sample-packer that would pass 16 samples in 14 bytes
(rather than in 16 bytes), which would save us 1/8th of the bandwidth.
That woul
On Tue, Mar 01, 2005 at 10:14:17PM -0800, John Gilmore wrote:
> > (and while I do have access to an mc4020 board, it is
> > not in a location that can receive ATSC signals and I'm not about to run
> > coax all over the place).
>
> I have to start by saying: either moving the mc4020 board to where
> There are about 10.76 Msymbols/sec in an ATSC signal, so you are going
> to have Nyquist problems if you try to represent them in 8M complex
> samples/sec. You'll need at least 10.76 complex MS/s. (Indeed you
> may notice that we were skating inside the edge by using 20
> non-complex MS/s on th
> (and while I do have access to an mc4020 board, it is
> not in a location that can receive ATSC signals and I'm not about to run
> coax all over the place).
I have to start by saying: either moving the mc4020 board to where the
antenna is, or running coax all over the place, will be MUCH easier
> I've been mulling over thinking about considering trying to rewrite the
> old atsc stuff over to the new architecture; it doesn't actually look
> that hard... maybe a day's work or so.
Hey, great! I was thinking of doing it too, but it would take me
awhile to get to it.
> However before doing
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