[Ground-station] DVB-S2 or -X bandwidth ?

[Howie DeFelice]

The STiD135 is an amazing chip. The last time I checked they weren't interested in talking to anyone that didn't have a huge requirement. That may have changed. DVB-S2x also supports down to 5% rolloff.

Howie AB2S

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________________________________
From: Ground-Station <ground-station-bounces at lists.openresearch.institute> on behalf of Ron Economos via Ground-Station <ground-station at lists.openresearch.institute>
Sent: Saturday, August 24, 2019 9:30:09 AM
To: ground-station at lists.openresearch.institute <ground-station at lists.openresearch.institute>
Subject: Re: [Ground-station] DVB-S2 or -X bandwidth ?

It used to be that demodulator chips didn't go below 1 Msym/s, but more
recent chips do. On QO-100, folks are using 500 and 333 ksym/s and even
lower. The STiD135 that I posted about previously is specified down to
100 ksym/s.

The actual bandwidth of a DVB-S2 signal is the symbol rate times the
roll-off factor + 1. The typical roll-off used is 0.2, so a 1 Msym/s
signal is 1.2 MHz wide. A 1 MHz bandwidth would require a 833 ksym/s signal.

Ron W6RZ

On 8/24/19 05:49, KC9SGV via Ground-Station wrote:
> Hi All,
> Is 1 MHz wide enough for DVB-S2 transmissions ?
> I cannot attach a picture here, but look on page 17 of this old TAPR paper.
> Seems like 2 MHz is the minimum bandwidth required ?
>
> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.tapr.org%2Fpdf%2FDCC2009-DATV-KB6CJZ-W6HHC.pdf&data=02%7C01%7C%7Cb8f5db9595734bb3f39008d7289802a9%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637022505662404251&sdata=YCKEQI2f%2Bhjk374WaNG8gxIiKCyL%2FLYChSGocDRLwNQ%3D&reserved=0
>
> Maybe only legacy ham Linear modes will be supported by our 1 MHz Rent-a- GEO effort ?
>
> Bernard,
> KC9SGV
>
>
> Sent from my iPad
>

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