Consultative Committee for Space Data Systems

Space Links Services

RF & Modulation Working Group

Spring 2015 Meeting

Pasadena, CA, USA, 23-27 March 2015

Comments to draft 26 GHz EESS recommendation

SLS-RFM_15-01 Reply to AI_14-08

J.L. Gerner, J.P. Millerioux, J.L. Issler (CNES)

1. Introduction

This document comes in response to AI_14-08 calling for comments to the current draft

recommendation 2.4.23 MODULATION METHODS AT HIGH SYMBOL RATE

TRANSMISSIONS, EARTH EXPLORATION SATELLITES (EES) 25.5-27.0 GHZ BAND,

SPACETO-EARTH, reproduced in annex for reference.

2. Comments / Proposed changes

1 Changes to considering (c)

Page / Section / Table

Page 2.4.23-1, considering (c)

Proposed change

Rewrite considering (c) as follows:

“that the use of now well-established bandwidth-efficient modulation techniques like filtered

suppressed carrier systems will reduce future risks of interference and reduce the need for

coordination”

Rationale

The recommendation 21-2R3, which is referred to in the current considering (c) , concerns

only the 2 GHz and 8 GHz bands; the proposed change will allow to publish rec 2.4.23

without having to wait for a – still hypothetical – approval by SFCG of the inclusion of the

26 GHz EESS band in SFCG Rec 21-2.

2 Considering (d) looks more like a noting

Page / Section / Table

Page 2.4.23-1, considering (d)

Proposed change

Convert considering (d) into a noting.

Rationale

Considerings are supposed to call for a recommends, which is not the case of considering

(d).

3 Considering (g) can be suppressed

Page / Section / Table

Page 2.4.23-1, considering (g)

Proposed change

Delete considering (g).

Rationale

Considering (g) is now redundant with new considering (c)

4 Changes to considering (h)

Page / Section / Table

Page 2.4.23-1, considering (h)

Proposed change

Change considering (h) from

“that with Square Root Raised Cosine filtering QPSK, OQPSK, 8PSK, 16APSK, 32APSK

and

64APSK bit-interleaved coded modulations (BiCM) spectra can meet the SFCG emission

mask for symbol rates in excess of 2 Ms/s with acceptable end-to-end losses;”

to

“that Square Root Raised Cosine filtering QPSK, OQPSK, 8PSK, 16APSK, 32APSK and

64APSK bit-interleaved coded modulations (BiCM) provide high bandwidth efficiency while

offering acceptable end-to-end losses;”

Rationale

Considering (h) should not refer to recommendation 21-2R3, which is only applicable to

bands 2 GHz and 8 GHz.

5 Changes to considering (m)

Page / Section / Table

Page 2.4.23-2, considering (m)

Proposed change

1. Clarify whether “in-band” refers to Rs or (1+alpha)Rs

2. Change from

“without equalization at the receiver”

to

“in case no equalization is implemented in the receiver”

Rationale

Clarifications

6 Typo in noting (4)

Page / Section / Table

Page 2.4.23-2, noting (4)

Proposed change

Change from

“1313-B-1”

to

“131.3-B-1”

Rationale

Editorial

7 Change to FN 6

Page / Section / Table

Page 2.4.23-2, FN 6

Proposed change

Change from

“For example, with CCSDS 131.2-B-1 (table 5-2): ModCod 6 for QPSK, 12 for 8PSK, 17 for

16-APSK, 22 for 32-APSK and 27 for 64-APSK”

to

“For example, with CCSDS 131.2-B-1 (table 5-2): ModCod 6 for QPSK, 12 for 8PSK, 17 for

16-APSK, 22 for 32-APSK and 27 for 64-APSK; or with CCSDS 131.3-B-1 (Annex D):

ModCod 10 or 11 for QPSK, 16 or 17 for 8PSK, 22 or 23 for 16-APSK, or27 or 28 for 32-

APSK”

Rationale

Include also the example of DVB-S2

8 New recommends (3)

Page / Section / Table

Page 2.4.23-2

Proposed change

Insert a new recommends (3) as follows:

“that a mission planning to operate in the 25.5-27.0 GHz band may use unfiltered BPSK,

QPSK or OQPSK, when the channel symbol rates is below or equal to 10 Ms/s;”

And renumber the following recommends.

Rationale

Recommends (2), while inviting to prefer bandwidth-efficient modulations below 10 Msps,

does not indicate what other modulations may still be used. The proposed recommends (3)

will, in particular, keep residual-carrier systems out of the 26 GHz EESS band.

9 Phase imbalance

Page / Section / Table

Page 2.4.23-3, recommends (8)

Proposed change

Change from

“that the modulator’s phase imbalance shall not exceed 3 degrees and the amplitude

imbalance shall not exceed 0.5 dB between the constellation points;”

to

“that the modulator’s phase imbalance shall not exceed 3 degrees and the amplitude

imbalance shall not exceed 0.5 dB between the constellation points for 16APSK and higher

order modulations;”

Rationale

Problem of consistency with recommendation 2.4.12A, which recommends 5 degrees and

0.5dB for BPSK, (O)QPSK, GMSK and 8PSK.

10 EVM values

Page / Section / Table

Page 2.4.23-3, recommends (9)

Proposed change

Add the EVM values

Rationale

The recommends refers to “following EVM values” but these are missing

11 Ratios outer/inner circle

Page / Section / Table

Page 2.4.23-4, Table 2.4.23-1 , column 16APSK

Proposed change

Change from

"g1=R2/R1= 3.15 2.85 2.75 2.60”

to

"g1=R2/R1= 3.15 2.85 2.75 2.70 2.60 2.57”

Rationale

For compatibility with DVB-S2

12 Ratios outer/inner circle

Page / Section / Table

Page 2.4.23-4, Table 2.4.23-1 , column 32APSK

Proposed change

Change from

"g1=R2/R1=2.84 2.72 2.54,

g2=R3/R1=5.27 4.87 4.33"

to

"g1=R2/R1=2.84 2.72 2.64 2.54 2.53,

g2=R3/R1=5.27 4.87 4.64 4.33 4.30"

Rationale

For compatibility with DVB-S2

13 Examples ratios outer/inner circle

Page / Section / Table

Page 2.4.23-4, FN 8

Proposed change

Change from

“See Table 5-1 from CCSDS 131.2-B-1for an example of the use of the values of the ratio of

outer to inner circles.”

to

“See Table 5-1 from CCSDS 131.2-B-1; or Table 9 and Table 10 from ETSI EN 302.307

V1.2.1 (called in CCSDS 131.3-B-1); for examples of the use of the values of the ratio of

outer to inner circles.”

Rationale

To give the reader the full picture

14 Foot Note 9

Page / Section / Table

Page 2.4.23-5, FN 9

Proposed change

Change from

“SRRC filtering can be practically implemented either with baseband filters or with RF post-

amplifier filters each able to fulfill SFCG Recommendation 21-2R2 (see CCSDS 413.0-G-

1).”

To

“SRRC filtering can be practically implemented either with baseband filters or with RF post-

amplifier filters”

Rationale

SFCG Recommendation 21-2R2 only applies to the 2 GHz and 8 GHz bands

15 No constellation mapping in CCSDS 131.0-B-1

Page / Section / Table

Pages 2.4.23-8/9/10/11/12

Proposed changes

Change title for Figure 2.4.23-4 from

“8PSK Symbol Mapping into Constellation (CCSDS 131.0-B-1 and 131.2-B-1)”

to

“8PSK Symbol Mapping into Constellation (CCSDS 131.2-B-1)”

Change in Page 2.4.23-9 from

“Modulations with coding in accordance with CCSDS 131.0-B-1 or 131.2-B-1”

to

“Modulations with coding in accordance with CCSDS 131.2-B-1”

In Figure 2.4.23-6, remove “131.0-B-1”

Change in Page 2.4.23-10 from

“Modulations with coding in accordance with CCSDS 131.0-B-1 or 131.2-B-1”

to

“Modulations with coding in accordance with CCSDS 131.2-B-1”

In Figure 2.4.23-7, remove “131.0-B-1”

Change in Page 2.4.23-11 from

“Modulations with coding in accordance with CCSDS 131.0-B-1 or 131.2-B-1”

to

“Modulations with coding in accordance with CCSDS 131.2-B-1”

In Figure 2.4.23-8, remove “131.0-B-1”

Rationale

There is no constellation mapping in CCSDS 131.0-B-1

Annex : Draft CCSDS Recommendation 2.4.23