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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

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": []
}