[Sls-rfm] Fw: CCSDS Review of CCSDS 401.0-P-25.1, Radio Frequency and Modulation Systems­Part 1: Earth Stations and Spacecraft - new proposal

Sank, Victor J. (GSFC-567.0)[AS and D, Inc.] victor.j.sank at nasa.gov
Thu Jun 16 12:39:58 UTC 2016


Enrico,
               I just want to state that I was in agreement with Wai but was negligent in not sending an email.  We will discuss your compromise suggestion.
Thanks,
Victor

From: Sls-rfm [mailto:sls-rfm-bounces at mailman.ccsds.org] On Behalf Of Enrico.Vassallo at esa.int
Sent: Thursday, June 16, 2016 5:41 AM
To: Fong, Wai H. (GSFC-5670) <wai.h.fong at nasa.gov>
Cc: sls-rfm at mailman.ccsds.org; Marco.Lanucara at esa.int
Subject: [Sls-rfm] Fw: CCSDS Review of CCSDS 401.0-P-25.1, Radio Frequency and Modulation Systems­Part 1: Earth Stations and Spacecraft - new proposal

Dear Wai,

nobody else submitted any comments to my first proposal so we are down to two RIDs where the two of us have a different view.
Here's my compromise proposal. Have a look at it and let me know if it could be OK for you.

1) MB-01

I partly agree and partly disagree with you.

Disagreement:

Also 16-32-64APSK are defined for the first time in this recommendation and not in other parts of 401.

Agreement:

It is true that pi/2-BPSK symbols for the frame headers are only defined and studied so far for the two standards mentioned.

Compromise:

New recommends (6):

“that the use of a frame header (see A1.5) and of QPSK pilot symbols should be used to improve the acquisition and tracking performance”

The new section A1.5 should be as in the RID but with an initial line saying that the spec is only for systems compliant with CCSDS 131.2-B-1 and CCSDS 131.2-B-1 and that for systems compliant with CCSDS 131.0-B-2 further work is needed.

We then add the task to the charter.


2) SM-01

Here I also partly agree and partly disagree with you.

Disagreement:

Recommends (7) limits the phase noise mask to channel symbol rates equal to or above 10 Ms/s. Therefore, using the typical 10^-4 for 2BL/Rs one gets 1000 Hz, which is already larger than the 100 Hz proposed by the RID

Agreement:

The recommendation does not prevent somebody from using 64-APSK at 100 ks/s. In that case, one would not know which phase noise mask to use.

Compromise:

I would do as we did for another issue in the ECSS standard, linking the lower integration limit to the mission specific symbol rate and PLL bandwidth.

Therefore, keeping a factor 10 margin in our pockets, I would propose to re-write recommends (7)

from
(7)        that the phase noise of the communication chain should be limited according to the mask given in figure 2.4.23-1 for channel symbol rates equal or above 10 Ms/s;

to
(7)        that the phase noise of the communication chain should be limited according to the mask given in figure 2.4.23-1 for channel symbol rates equal or above 10 Ms/s for which the lower mask limit shall be 100 Hz; that the same mask should be used for channel symbol rates below 10 Ms/s by setting the lower validity limit in accordance with the mission channel symbol rate and PLL loop bandwidth.


Would you be able to accept this compromise? The ESA colleagues originating the RIDs are OK.

Regards, Enrico

----- Forwarded by Enrico Vassallo/esoc/ESA on 16/06/2016 11:17 -----

From:        Enrico Vassallo/esoc/ESA
To:        "Fong, Wai H. (GSFC-5670)" <wai.h.fong at nasa.gov<mailto:wai.h.fong at nasa.gov>>
Cc:        "Marco.Lanucara at esa.int<mailto:Marco.Lanucara at esa.int>" <Marco.Lanucara at esa.int<mailto:Marco.Lanucara at esa.int>>, "Salvador.Marti at esa.int<mailto:Salvador.Marti at esa.int>" <Salvador.Marti at esa.int<mailto:Salvador.Marti at esa.int>>, "sls-rfm at mailman.ccsds.org<mailto:sls-rfm at mailman.ccsds.org>" <sls-rfm at mailman.ccsds.org<mailto:sls-rfm at mailman.ccsds.org>>
Date:        20/05/2016 08:48
Subject:        Re: [Sls-rfm] CCSDS Review of CCSDS 401.0-P-25.1, Radio Frequency and Modulation Systems­Part 1: Earth Stations and Spacecraft
________________________________


Wai,
your position is noted.
I will open discussion after June 10 waiting for other WG members' comments.

Regards, Enrico



From:        "Fong, Wai H. (GSFC-5670)" <wai.h.fong at nasa.gov<mailto:wai.h.fong at nasa.gov>>
To:        "Enrico.Vassallo at esa.int<mailto:Enrico.Vassallo at esa.int>" <Enrico.Vassallo at esa.int<mailto:Enrico.Vassallo at esa.int>>, "sls-rfm at mailman.ccsds.org<mailto:sls-rfm at mailman.ccsds.org>" <sls-rfm at mailman.ccsds.org<mailto:sls-rfm at mailman.ccsds.org>>
Cc:        "Marco.Lanucara at esa.int<mailto:Marco.Lanucara at esa.int>" <Marco.Lanucara at esa.int<mailto:Marco.Lanucara at esa.int>>, "Salvador.Marti at esa.int<mailto:Salvador.Marti at esa.int>" <Salvador.Marti at esa.int<mailto:Salvador.Marti at esa.int>>
Date:        19/05/2016 20:22
Subject:        Re: [Sls-rfm] CCSDS Review of CCSDS 401.0-P-25.1, Radio Frequency and Modulation Systems­Part 1: Earth Stations and Spacecraft
________________________________



Enrico,

My comments are:
1.        ESA-MB-01:  The addition of proposed text to specify pi/2-BPSK symbols is inconsistent with the rest of the text that recommends only QPSK, OQPSK, 8PSK, 16APSK, 32APSK, or 64APSK, modulations.  In addition, since pi/2-BPSK only exist in CCSDS 131.2-B-1 and CCSDS 131.2-B-1 and not in 401.0-B, it has not been studied formally as a modulation technique where we would need evaluate the modulation and demodulation complexities.  I would reject this RID.
2.        ESA-SM-01: The inclusion of 10Hz-100Hz specification of the phase noise mask is necessary because there is no lower bound on symbol rate of the recommendation.  Recommends (2) in fact specifies QPSK, OQPSK, or 8PSK modulations below 10 Ms/s where there could be significant AWGN noise power.  Missions trying to operate with very narrow of loop bandwidths to mitigate AWGN noise need to know that they could increase phase noise.  I would reject this RID as well.
The rest I agree with.

Regards,

Wai Fong, Ph.D.
Communications Engineer
Flight Microwave and Telecommunications Systems Branch
NASA Goddard Space Flight Center
Code 567
Greenbelt, MD  20771


From: <sls-rfm-bounces at mailman.ccsds.org<mailto:sls-rfm-bounces at mailman.ccsds.org>> on behalf of Enrico Vassallo <Enrico.Vassallo at esa.int<mailto:Enrico.Vassallo at esa.int>>
Date: Thursday, May 19, 2016 at 9:49 AM
To: "sls-rfm at mailman.ccsds.org<mailto:sls-rfm at mailman.ccsds.org>" <sls-rfm at mailman.ccsds.org<mailto:sls-rfm at mailman.ccsds.org>>
Cc: "Marco.Lanucara at esa.int<mailto:Marco.Lanucara at esa.int>" <Marco.Lanucara at esa.int<mailto:Marco.Lanucara at esa.int>>, "Salvador.Marti at esa.int<mailto:Salvador.Marti at esa.int>" <Salvador.Marti at esa.int<mailto:Salvador.Marti at esa.int>>
Subject: [Sls-rfm] CCSDS Review of CCSDS 401.0-P-25.1, Radio Frequency and Modulation Systems­Part 1: Earth Stations and Spacecraft

Dear All,

this is to inform you of the outcome of the above review.

CNES, DLR, INPE and JAXA concurred with the pink sheets.

ESA and EUM generated 3 RIDs each. They are attached for your review.

My proposal is:

1) ESA-MB-01

We were initially thinking of adding Pi/2-BPSK symbols definition as an additional recommendation in 401. However, it makes more sense to have it inside recommendation 2.4.23 that becomes self standing.

Disposition: ACCEPTED

2) ESA-ML-01

Makes the recommendation ECSS compatible (specifications cannot be in footnotes).

Disposition: ACCEPTED

3) ESA-SM-01

The phase noise between 10 and 100 Hz is not important for this kind of missions with at least 10 Ms/s (even for 1 Ms/s that is behind recommends (2)).

Disposition: ACCEPTED

4) EUM-XE-001

Editorial clarification.

Disposition: ACCEPTED

5) EUM-XE-002

Editorial.

Disposition: ACCEPTED

6) EUM-XE-003

Almost editorial. In the ESA implementation, pilots are used also for lower order modulations but the suggestion of this RID is reasonable.

Disposition: ACCEPTED



If I do not hear from you by June 10, I will assume that the WG concurs with my proposed disposition and will send disposed RIDs and final version of the recommendation to the CCSDS management for approval.

Regards, Enrico



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