DVB-S2 Extension v1.0.0

Abstract

This document defines the dvbs2 extension namespace for the Signal Metadata Format (SigMF) specification. This extension namespace defines new datatypes and properties of DVB-S2/S2X signals extending the global object in SigMF Recordings.

Table of Contents

• DVB-S2 Extension v1.0.0
  • Abstract
  • Table of Contents
  • Acronyms and Terms
  • Datatypes
  • Global Object
    • The modcod Union
    • The rolloff Enum
    • The fecframe_size Enum
  • Captures Array
  • Annotations Array
  • Collections
  • Examples
    • CCM Recording
    • VCM Recording

Acronyms and Terms

Acronym	Description
ACM	Adaptive coding and modulation
CCM	Constant coding and modulation
GS	Generic stream
ISSYI	Input stream synchronization indicator
MIS	Multiple input stream
MODCOD	Modulation and coding scheme
PL	Physical layer
SIS	Single input stream
TS	Transport stream
VCM	Variable coding and modulation

Datatypes

The dvbs2 namespace defines the following datatypes:

type	long-form name	description
union	Union type	Union type accepting values represented by two or more core datatypes.
enum	Enumerated type	Enumeration accepting a defined set of elements represented by a core datatype.

Global Object

The following names are specified in the dvbs2 namespace and should be used in the global object:

name	required	type	description
symbol_rate	true	double	The symbol rate of the signal in symbols per second (or bauds).
gs	false	boolean	Whether the signal carries a continuous GS. False when the signal carries a packetized TS. If omitted, defaults to false (TS).
mis	false	boolean	Whether the signal has MIS configuration. False when the signal has SIS configuration. If omitted, defaults to false (SIS).
acm_vcm	false	boolean	Whether the signal has ACM or VCM. False when the signal consists of CCM. If omitted, defaults to false (CCM).
issyi	false	boolean	Whether the signal has ISSYI active. If omitted, defaults to false (inactive).
npd	false	boolean	Whether the signal has null-packet deletion active. If omitted, defaults to false (inactive).
rolloff	false	enum	Signal’s baseband shaping roll-off factor given by the rolloff enum.
modcod	false	array	Array of MODCODs present in the signal, each represented by a modcod union value. Should contain a single element in CCM mode (when acm_vcm is false or omitted). When omitted, it is implied the MODCODs are unknown or dynamically changing and should be discovered by the demodulator.
fecframe_size	false	array	Array of FECFRAME sizes present in the signal, each represented by a fecframe_size enum value. Should contain a single element in CCM mode (when acm_vcm is false or omitted). When omitted, it is implied the FECFRAME sizes are unknown or dynamically changing and should be discovered by the demodulator.
pilots	false	boolean	Whether the signal contains PL pilots. When omitted, it is implied the presence or absence of pilots is unknown or dynamically changing and should be discovered by the demodulator.
gold_code	false	uint	n-th Gold code for PL descrambling. If omitted, defaults to code 0.

The modcod Union

A modcod union value takes one of the following types:

type	description
string	Canonical name of the signal’s MODCOD with the constellation in upper case, followed by a space and the code rate. For example, “QPSK 1/4” or “32APSK 9/10”.
uint	PLS code decimal value representing the MODCOD as given by EN 302 307-1, Table 12 (DVB-S2), or EN 302 307-2, Table 17 (DVB-S2X). For example, 1 for QPSK 1/4 or 28 for 32APSK 9/10.

The rolloff Enum

The rolloff double-typed enum can have one of the following values:

value	description
0.35	DVB-S2 and DVB-S2X
0.25	DVB-S2 and DVB-S2X
0.2	DVB-S2 and DVB-S2X
0.15	DVB-S2X
0.1	DVB-S2X
0.05	DVB-S2X

The fecframe_size Enum

The fecframe_size string-typed enum can have one of the following values:

value	description
normal	Normal FECFRAME size (64800 bits).
short	Short FECFRAME size (16200 bits).
medium	Medium FECFRAME size (32400 bits), DVB-S2X only.

Captures Array

dvbs2 does not extend Captures.

Annotations Array

dvbs2 does not extend Annotations.

Collections

dvbs2 does not extend SigMF Collections.

Examples

The following SigMF .sigmf-meta examples illustrate CCM and VCM IQ recordings:

CCM Recording

The following example is a baseband CCM DVB-S2 signal collected with a sample rate of 2 Msamples/sec and consisting of a 1 Mbaud QPSK 3/5 MODCOD, pulse-shaped with 0.2 roll-off factor, with normal FECFRAME size, and PL pilots enabled:

{
    "global": {
        "core:datatype": "cu8",
        "core:sample_rate": 2000000,
        "core:version": "1.0.0",
        "dvbs2:symbol_rate": 1000000,
        "dvbs2:rolloff": 0.2,
        "dvbs2:modcod": [
            "QPSK 3/5"
        ],
        "dvbs2:fecframe_size": [
            "normal"
        ],
        "dvbs2:pilots": true
    },
    "captures": [
        {
            "core:sample_start": 0
        }
    ],
    "annotations": []
}

NOTE: The MODCOD and FECFRAME size arrays have a single element, given that this is a CCM recording.

VCM Recording

The following example is also a 1 Mbaud baseband DVB-S2 signal collected with a sample rate of 2 Msamples/sec. However, in contrast to the previous example, this recording carries two MODCODs simultaneously in VCM mode, QPSK 1/4 and 8PSK 3/5, while flagging dvbs2:acm_vcm to true:

{
    "global": {
        "core:datatype": "cu8",
        "core:sample_rate": 2000000,
        "core:version": "1.0.0",
        "dvbs2:symbol_rate": 1000000,
        "dvbs2:rolloff": 0.2,
        "dvbs2:acm_vcm": true,
        "dvbs2:modcod": [
            "QPSK 1/4",
            "8PSK 3/5"
        ],
        "dvbs2:fecframe_size": [
            "normal"
        ],
        "dvbs2:pilots": true
    },
    "captures": [
        {
            "core:sample_start": 0
        }
    ],
    "annotations": []
}