Merged master 8748
This commit is contained in:
Jordan Sherer
@@ -0,0 +1,31 @@
|
||||
"CQ K1JT FN20"
|
||||
"CQ PJ4/K1JT"
|
||||
"<K1JT> W6CQZ"
|
||||
"DE W6CQZ CM87"
|
||||
"DE PJ4/K1JT"
|
||||
"W6CQZ <K1JT> S4"
|
||||
"QRZ K1JT"
|
||||
"PJ4/W6CQZ S4"
|
||||
"K1JT <W6CQZ> R S3"
|
||||
"PJ4/K1JT R S3"
|
||||
"<W6CQZ> K1JT RRR"
|
||||
"W6CQZ <K1JT> RRR"
|
||||
"DE PJ4/K1JT RRR"
|
||||
"73 DE W6CQZ CM87"
|
||||
"73 DE PJ4/K1JT"
|
||||
"TNX VICTORIA 73 GL"
|
||||
"OP HARRY 73 GL"
|
||||
"5 W DIPOLE"
|
||||
"10 W VERTICAL"
|
||||
"1 W 0 DBD"
|
||||
"1500 W 21 DBD 73 GL"
|
||||
"PSE QSY 1811 KHZ"
|
||||
"WX SNOW -5 C CALM"
|
||||
"CUL JACK"
|
||||
"."
|
||||
"CQ K1JT FN20"
|
||||
"<K1JT> W6CQZ"
|
||||
"W6CQZ <K1JT> S4"
|
||||
"K1JT <W6CQZ> R S3"
|
||||
"<W6CQZ> K1JT RRR"
|
||||
"TNX JOE 73 GL"
|
||||
File diff suppressed because it is too large
Load Diff
Binary file not shown.
|
Before Width: | Height: | Size: 19 KiB |
@@ -1,165 +0,0 @@
|
||||
#include "MessageAggregatorMainWindow.hpp"
|
||||
|
||||
#include <QtWidgets>
|
||||
#include <QDateTime>
|
||||
|
||||
#include "DecodesModel.hpp"
|
||||
#include "BeaconsModel.hpp"
|
||||
#include "ClientWidget.hpp"
|
||||
|
||||
using port_type = MessageServer::port_type;
|
||||
|
||||
namespace
|
||||
{
|
||||
char const * const headings[] = {
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Time On"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Time Off"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Callsign"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Grid"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Name"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Frequency"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Mode"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Sent"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Rec'd"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Power"),
|
||||
QT_TRANSLATE_NOOP ("MessageAggregatorMainWindow", "Comments"),
|
||||
};
|
||||
}
|
||||
|
||||
MessageAggregatorMainWindow::MessageAggregatorMainWindow ()
|
||||
: log_ {new QStandardItemModel {0, 11, this}}
|
||||
, decodes_model_ {new DecodesModel {this}}
|
||||
, beacons_model_ {new BeaconsModel {this}}
|
||||
, server_ {new MessageServer {this}}
|
||||
, multicast_group_line_edit_ {new QLineEdit}
|
||||
, log_table_view_ {new QTableView}
|
||||
{
|
||||
// logbook
|
||||
int column {0};
|
||||
for (auto const& heading : headings)
|
||||
{
|
||||
log_->setHeaderData (column++, Qt::Horizontal, tr (heading));
|
||||
}
|
||||
connect (server_, &MessageServer::qso_logged, this, &MessageAggregatorMainWindow::log_qso);
|
||||
|
||||
// menu bar
|
||||
auto file_menu = menuBar ()->addMenu (tr ("&File"));
|
||||
|
||||
auto exit_action = new QAction {tr ("E&xit"), this};
|
||||
exit_action->setShortcuts (QKeySequence::Quit);
|
||||
exit_action->setToolTip (tr ("Exit the application"));
|
||||
file_menu->addAction (exit_action);
|
||||
connect (exit_action, &QAction::triggered, this, &MessageAggregatorMainWindow::close);
|
||||
|
||||
view_menu_ = menuBar ()->addMenu (tr ("&View"));
|
||||
|
||||
// central layout
|
||||
auto central_layout = new QVBoxLayout;
|
||||
|
||||
// server details
|
||||
auto port_spin_box = new QSpinBox;
|
||||
port_spin_box->setMinimum (1);
|
||||
port_spin_box->setMaximum (std::numeric_limits<port_type>::max ());
|
||||
auto group_box_layout = new QFormLayout;
|
||||
group_box_layout->addRow (tr ("Port number:"), port_spin_box);
|
||||
group_box_layout->addRow (tr ("Multicast Group (blank for unicast server):"), multicast_group_line_edit_);
|
||||
auto group_box = new QGroupBox {tr ("Server Details")};
|
||||
group_box->setLayout (group_box_layout);
|
||||
central_layout->addWidget (group_box);
|
||||
|
||||
log_table_view_->setModel (log_);
|
||||
log_table_view_->verticalHeader ()->hide ();
|
||||
central_layout->addWidget (log_table_view_);
|
||||
|
||||
// central widget
|
||||
auto central_widget = new QWidget;
|
||||
central_widget->setLayout (central_layout);
|
||||
|
||||
// main window setup
|
||||
setCentralWidget (central_widget);
|
||||
setDockOptions (AnimatedDocks | AllowNestedDocks | AllowTabbedDocks);
|
||||
setTabPosition (Qt::BottomDockWidgetArea, QTabWidget::North);
|
||||
|
||||
// connect up server
|
||||
connect (server_, &MessageServer::error, [this] (QString const& message) {
|
||||
QMessageBox::warning (this, QApplication::applicationName (), tr ("Network Error"), message);
|
||||
});
|
||||
connect (server_, &MessageServer::client_opened, this, &MessageAggregatorMainWindow::add_client);
|
||||
connect (server_, &MessageServer::client_closed, this, &MessageAggregatorMainWindow::remove_client);
|
||||
connect (server_, &MessageServer::client_closed, decodes_model_, &DecodesModel::clear_decodes);
|
||||
connect (server_, &MessageServer::client_closed, beacons_model_, &BeaconsModel::clear_decodes);
|
||||
connect (server_, &MessageServer::decode, [this] (bool is_new, QString const& id, QTime time
|
||||
, qint32 snr, float delta_time
|
||||
, quint32 delta_frequency, QString const& mode
|
||||
, QString const& message) {
|
||||
decodes_model_->add_decode (is_new, id, time, snr, delta_time, delta_frequency, mode, message
|
||||
, dock_widgets_[id]->fast_mode ());});
|
||||
connect (server_, &MessageServer::WSPR_decode, beacons_model_, &BeaconsModel::add_beacon_spot);
|
||||
connect (server_, &MessageServer::clear_decodes, decodes_model_, &DecodesModel::clear_decodes);
|
||||
connect (server_, &MessageServer::clear_decodes, beacons_model_, &BeaconsModel::clear_decodes);
|
||||
connect (decodes_model_, &DecodesModel::reply, server_, &MessageServer::reply);
|
||||
|
||||
// UI behaviour
|
||||
connect (port_spin_box, static_cast<void (QSpinBox::*)(int)> (&QSpinBox::valueChanged)
|
||||
, [this] (port_type port) {server_->start (port);});
|
||||
connect (multicast_group_line_edit_, &QLineEdit::editingFinished, [this, port_spin_box] () {
|
||||
server_->start (port_spin_box->value (), QHostAddress {multicast_group_line_edit_->text ()});
|
||||
});
|
||||
|
||||
port_spin_box->setValue (2237); // start up in unicast mode
|
||||
show ();
|
||||
}
|
||||
|
||||
void MessageAggregatorMainWindow::log_qso (QString const& /*id*/, QDateTime timeOff, QString const& dx_call, QString const& dx_grid
|
||||
, Frequency dial_frequency, QString const& mode, QString const& report_sent
|
||||
, QString const& report_received, QString const& tx_power, QString const& comments
|
||||
, QString const& name, QDateTime timeOn)
|
||||
{
|
||||
QList<QStandardItem *> row;
|
||||
row << new QStandardItem {timeOn.toString ("dd-MMM-yyyy hh:mm:ss")}
|
||||
<< new QStandardItem {timeOff.toString ("dd-MMM-yyyy hh:mm:ss")}
|
||||
<< new QStandardItem {dx_call}
|
||||
<< new QStandardItem {dx_grid}
|
||||
<< new QStandardItem {name}
|
||||
<< new QStandardItem {Radio::frequency_MHz_string (dial_frequency)}
|
||||
<< new QStandardItem {mode}
|
||||
<< new QStandardItem {report_sent}
|
||||
<< new QStandardItem {report_received}
|
||||
<< new QStandardItem {tx_power}
|
||||
<< new QStandardItem {comments};
|
||||
log_->appendRow (row);
|
||||
log_table_view_->resizeColumnsToContents ();
|
||||
log_table_view_->horizontalHeader ()->setStretchLastSection (true);
|
||||
log_table_view_->scrollToBottom ();
|
||||
}
|
||||
|
||||
void MessageAggregatorMainWindow::add_client (QString const& id, QString const& version, QString const& revision)
|
||||
{
|
||||
auto dock = new ClientWidget {decodes_model_, beacons_model_, id, version, revision, this};
|
||||
dock->setAttribute (Qt::WA_DeleteOnClose);
|
||||
auto view_action = dock->toggleViewAction ();
|
||||
view_action->setEnabled (true);
|
||||
view_menu_->addAction (view_action);
|
||||
addDockWidget (Qt::BottomDockWidgetArea, dock);
|
||||
connect (server_, &MessageServer::status_update, dock, &ClientWidget::update_status);
|
||||
connect (server_, &MessageServer::decode, dock, &ClientWidget::decode_added);
|
||||
connect (server_, &MessageServer::WSPR_decode, dock, &ClientWidget::beacon_spot_added);
|
||||
connect (dock, &ClientWidget::do_reply, decodes_model_, &DecodesModel::do_reply);
|
||||
connect (dock, &ClientWidget::do_halt_tx, server_, &MessageServer::halt_tx);
|
||||
connect (dock, &ClientWidget::do_free_text, server_, &MessageServer::free_text);
|
||||
connect (view_action, &QAction::toggled, dock, &ClientWidget::setVisible);
|
||||
dock_widgets_[id] = dock;
|
||||
server_->replay (id);
|
||||
}
|
||||
|
||||
void MessageAggregatorMainWindow::remove_client (QString const& id)
|
||||
{
|
||||
auto iter = dock_widgets_.find (id);
|
||||
if (iter != std::end (dock_widgets_))
|
||||
{
|
||||
(*iter)->close ();
|
||||
dock_widgets_.erase (iter);
|
||||
}
|
||||
}
|
||||
|
||||
#include "moc_MessageAggregatorMainWindow.cpp"
|
||||
@@ -1,336 +0,0 @@
|
||||
[[PROTOCOL_OVERVIEW]]
|
||||
=== Overview
|
||||
|
||||
All QSO modes except ISCAT use structured messages that compress
|
||||
user-readable information into fixed-length packets of 72 bits. Each
|
||||
message consists of two 28-bit fields normally used for callsigns and
|
||||
a 15-bit field for a grid locator, report, acknowledgment, or 73. An
|
||||
additional bit flags a message containing arbitrary alphanumeric text,
|
||||
up to 13 characters. Special cases allow other information such as
|
||||
add-on callsign prefixes (e.g., ZA/K1ABC) or suffixes (e.g., K1ABC/P)
|
||||
to be encoded. The basic aim is to compress the most common messages
|
||||
used for minimally valid QSOs into a fixed 72-bit length. Information
|
||||
payloads in FT8 include 3 additional bits (75 bits total), with
|
||||
definitions yet to be defined.
|
||||
|
||||
A standard amateur callsign consists of a one- or two-character
|
||||
prefix, at least one of which must be a letter, followed by a digit
|
||||
and a suffix of one to three letters. Within these rules, the number
|
||||
of possible callsigns is equal to 37×36×10×27×27×27, or somewhat over
|
||||
262 million. (The numbers 27 and 37 arise because in the first and
|
||||
last three positions a character may be absent, or a letter, or
|
||||
perhaps a digit.) Since 2^28^ is more than 268 million, 28 bits are
|
||||
enough to encode any standard callsign uniquely. Similarly, the number
|
||||
of 4-digit Maidenhead grid locators on earth is 180×180 = 32,400,
|
||||
which is less than 2^15^ = 32,768; so a grid locator requires 15 bits.
|
||||
|
||||
Some 6 million of the possible 28-bit values are not needed for
|
||||
callsigns. A few of these slots have been assigned to special message
|
||||
components such as `CQ`, `DE`, and `QRZ`. `CQ` may be followed by three
|
||||
digits to indicate a desired callback frequency. (If K1ABC transmits
|
||||
on a standard calling frequency, say 50.280, and sends `CQ 290 K1ABC
|
||||
FN42`, it means that s/he will listen on 50.290 and respond there to
|
||||
any replies.) A numerical signal report of the form `–nn` or
|
||||
`R–nn` can be sent in place of a grid locator. (As originally
|
||||
defined, numerical signal reports `nn` were required to fall between -01
|
||||
and -30 dB. Recent program versions accommodate reports between
|
||||
-50 and +49 dB.) A country prefix or portable suffix may be
|
||||
attached to one of the callsigns. When this feature is used the
|
||||
additional information is sent in place of the grid locator or by
|
||||
encoding additional information into some of the 6 million available
|
||||
slots mentioned above.
|
||||
|
||||
Finally, the message compression algorithm supports messages starting
|
||||
with `CQ AA` through `CQ ZZ`. Such messages are encoded by
|
||||
sending `E9AA` through `E9ZZ` in place of the first callsign of a
|
||||
standard message. Upon reception these calls are converted back to
|
||||
the form `CQ AA` through `CQ ZZ`.
|
||||
|
||||
To be useful on channels with low signal-to-noise ratio, this kind of
|
||||
lossless message compression requires use of a strong forward error
|
||||
correcting (FEC) code. Different codes are used for each mode.
|
||||
Accurate synchronization of time and frequency is required between
|
||||
transmitting and receiving stations. As an aid to the decoders, each
|
||||
protocol includes a "`sync vector`" of known symbols interspersed with
|
||||
the information-carrying symbols. Generated waveforms for all of the
|
||||
_WSJT-X_ modes have continuous phase and constant envelope.
|
||||
|
||||
[[SLOW_MODES]]
|
||||
=== Slow Modes
|
||||
|
||||
[[FT8PRO]]
|
||||
==== FT8
|
||||
|
||||
Forward error correction (FEC) in FT8 uses a low-density
|
||||
parity check (LDPC) code with 75 information bits, a 12-bit cyclic
|
||||
redundancy check (CRC), and 174 channel symbols. It is thus called an
|
||||
LDPC (174,87) code. Synchronization uses 7×7 Costas arrays at the
|
||||
beginning, middle, and end of each transmission. Modulation is 8-tone
|
||||
frequency-shift keying (8-FSK) at 12000/1920 = 6.25 baud. Each
|
||||
transmitted symbol carries three bits, so the total number of channel
|
||||
symbols is 174/3 + 21 = 79. The total occupied bandwidth is
|
||||
8 × 6.25 = 50 Hz.
|
||||
|
||||
[[JT4PRO]]
|
||||
==== JT4
|
||||
|
||||
FEC in JT4 uses a strong convolutional code with constraint length
|
||||
K=32, rate r=1/2, and a zero tail. This choice leads to an encoded
|
||||
message length of (72+31) x 2 = 206 information-carrying bits.
|
||||
Modulation is 4-tone frequency-shift keying (4-FSK) at 11025 / 2520 =
|
||||
4.375 baud. Each symbol carries one information bit (the most
|
||||
significant bit) and one synchronizing bit. The two 32-bit
|
||||
polynomials used for convolutional encoding have hexadecimal values
|
||||
0xf2d05351 and 0xe4613c47, and the ordering of encoded bits is
|
||||
scrambled by an interleaver. The pseudo-random sync vector is the
|
||||
following sequence (60 bits per line):
|
||||
|
||||
000011000110110010100000001100000000000010110110101111101000
|
||||
100100111110001010001111011001000110101010101111101010110101
|
||||
011100101101111000011011000111011101110010001101100100011111
|
||||
10011000011000101101111010
|
||||
|
||||
|
||||
[[JT9PRO]]
|
||||
==== JT9
|
||||
|
||||
FEC in JT9 uses the same strong convolutional code as JT4: constraint
|
||||
length K=32, rate r=1/2, and a zero tail, leading to an encoded
|
||||
message length of (72+31) × 2 = 206 information-carrying
|
||||
bits. Modulation is nine-tone frequency-shift keying, 9-FSK at
|
||||
12000.0/6912 = 1.736 baud. Eight tones are used for data, one for
|
||||
synchronization. Eight data tones means that three data bits are
|
||||
conveyed by each transmitted information symbol. Sixteen symbol
|
||||
intervals are devoted to synchronization, so a transmission requires a
|
||||
total of 206 / 3 + 16 = 85 (rounded up) channel symbols. The sync
|
||||
symbols are those numbered 1, 2, 5, 10, 16, 23, 33, 35, 51, 52, 55,
|
||||
60, 66, 73, 83, and 85 in the transmitted sequence. Tone spacing of
|
||||
the 9-FSK modulation for JT9A is equal to the keying rate, 1.736 Hz.
|
||||
The total occupied bandwidth is 9 × 1.736 = 15.6 Hz.
|
||||
|
||||
[[JT65PRO]]
|
||||
==== JT65
|
||||
|
||||
A detailed description of the JT65 protocol was published in
|
||||
{jt65protocol} for September-October, 2005. A Reed Solomon (63,12)
|
||||
error-control code converts 72-bit user messages into sequences of 63
|
||||
six-bit information-carrying symbols. These are interleaved with
|
||||
another 63 symbols of synchronizing information according to the
|
||||
following pseudo-random sequence:
|
||||
|
||||
100110001111110101000101100100011100111101101111000110101011001
|
||||
101010100100000011000000011010010110101010011001001000011111111
|
||||
|
||||
|
||||
The synchronizing tone is normally sent in each interval having a
|
||||
"`1`" in the sequence. Modulation is 65-FSK at 11025/4096 = 2.692
|
||||
baud. Frequency spacing between tones is equal to the keying rate for
|
||||
JT65A, and 2 and 4 times larger for JT65B and JT65C. For EME QSOs the
|
||||
signal report OOO is sometimes used instead of numerical signal
|
||||
reports. It is conveyed by reversing sync and data positions in the
|
||||
transmitted sequence. Shorthand messages for RO, RRR, and 73 dispense
|
||||
with the sync vector entirely and use time intervals of 16384/11025 =
|
||||
1.486 s for pairs of alternating tones. The lower frequency is the
|
||||
same as that of the sync tone used in long messages, and the frequency
|
||||
separation is 110250/4096 = 26.92 Hz multiplied by n for JT65A, with n
|
||||
= 2, 3, 4 used to convey the messages RO, RRR, and 73.
|
||||
|
||||
[[QRA64_PROTOCOL]]
|
||||
==== QRA64
|
||||
|
||||
QRA64 is an experimental mode intended for EME and other extreme
|
||||
weak-signal applications. Its internal code was designed by IV3NWV.
|
||||
The protocol uses a (63,12) **Q**-ary **R**epeat **A**ccumulate code
|
||||
that is inherently better than the Reed Solomon (63,12) code used in
|
||||
JT65, yielding a 1.3 dB advantage. A new synchronizing scheme is based
|
||||
on three 7 x 7 Costas arrays. This change yields another 1.9 dB
|
||||
advantage.
|
||||
|
||||
In most respects the current implementation of QRA64 is operationally
|
||||
similar to JT65. QRA64 does not use two-tone shorthand messages, and
|
||||
it makes no use of a callsign database. Rather, additional
|
||||
sensitivity is gained by making use of already known information as a
|
||||
QSO progresses -- for example, when reports are being exchanged and
|
||||
you have already decoded both callsigns in a previous transmission.
|
||||
QRA64 presently offers no message averaging capability, though that
|
||||
feature may be added. In early tests, many EME QSOs were made using
|
||||
submodes QRA64A-E on bands from 144 MHz to 24 GHz.
|
||||
|
||||
[[SLOW_SUMMARY]]
|
||||
==== Summary
|
||||
|
||||
Table 2 provides a brief summary parameters for the slow modes in
|
||||
_WSJT-X_. Parameters K and r specify the constraint length and rate
|
||||
of the convolutional codes; n and k specify the sizes of the
|
||||
(equivalent) block codes; Q is the alphabet size for the
|
||||
information-carrying channel symbols; Sync Energy is the fraction of
|
||||
transmitted energy devoted to synchronizing symbols; and S/N Threshold
|
||||
is the signal-to-noise ratio (in a 2500 Hz reference bandwidth) above
|
||||
which the probability of decoding is 50% or higher.
|
||||
|
||||
[[SLOW_TAB]]
|
||||
.Parameters of Slow Modes
|
||||
[width="90%",cols="3h,^3,^2,^1,^2,^2,^2,^2,^2,^2",frame=topbot,options="header"]
|
||||
|===============================================================================
|
||||
|Mode |FEC Type |(n,k) | Q|Modulation type|Keying rate (Baud)|Bandwidth (Hz)
|
||||
|Sync Energy|Tx Duration (s)|S/N Threshold (dB)
|
||||
|FT8 |LDPC, r=1/2|(174,87)| 8| 8-FSK| 6.25 | 50.0 | 0.27| 12.6 | -21
|
||||
|JT4A |K=32, r=1/2|(206,72)| 2| 4-FSK| 4.375| 17.5 | 0.50| 47.1 | -23
|
||||
|JT9A |K=32, r=1/2|(206,72)| 8| 9-FSK| 1.736| 15.6 | 0.19| 49.0 | -27
|
||||
|JT65A |Reed Solomon|(63,12) |64|65-FSK| 2.692| 177.6 | 0.50| 46.8 | -25
|
||||
|QRA64A|Q-ary Repeat Accumulate|(63,12) |64|64-FSK|1.736|111.1|0.25|48.4| -26
|
||||
| WSPR |K=32, r=1/2|(162,50)| 2| 4-FSK| 1.465| 5.9 | 0.50|110.6 | -28
|
||||
|===============================================================================
|
||||
|
||||
Submodes of JT4, JT9, JT65, and QRA64 offer wider tone spacings for
|
||||
circumstances that may require them, such significant Doppler spread.
|
||||
Table 3 summarizes the tone spacings, bandwidths, and approximate
|
||||
threshold sensitivities of the various submodes when spreading is
|
||||
comparable to tone spacing.
|
||||
|
||||
[[SLOW_SUBMODES]]
|
||||
.Parameters of Slow Submodes
|
||||
[width="50%",cols="h,3*^",frame=topbot,options="header"]
|
||||
|=====================================
|
||||
|Mode |Tone Spacing |BW (Hz)|S/N (dB)
|
||||
|FT8 |6.25 | 50.0 |-21
|
||||
|JT4A |4.375| 17.5 |-23
|
||||
|JT4B |8.75 | 30.6 |-22
|
||||
|JT4C |17.5 | 56.9 |-21
|
||||
|JT4D |39.375| 122.5 |-20
|
||||
|JT4E |78.75| 240.6 |-19
|
||||
|JT4F |157.5| 476.9 |-18
|
||||
|JT4G |315.0| 949.4 |-17
|
||||
|JT9A |1.736| 15.6 |-27
|
||||
|JT9B |3.472| 29.5 |-26
|
||||
|JT9C |6.944| 57.3 |-25
|
||||
|JT9D |13.889| 112.8 |-24
|
||||
|JT9E |27.778| 224.0 |-23
|
||||
|JT9F |55.556| 446.2 |-22
|
||||
|JT9G |111.111|890.6 |-21
|
||||
|JT9H |222.222|1779.5|-20
|
||||
|JT65A |2.692| 177.6 |-25
|
||||
|JT65B |5.383| 352.6 |-25
|
||||
|JT65C |10.767| 702.5 |-25
|
||||
|QRA64A|1.736| 111.1 |-26
|
||||
|QRA64B|3.472| 220.5 |-25
|
||||
|QRA64C|6.944| 439.2 |-24
|
||||
|QRA64D|13.889| 876.7 |-23
|
||||
|QRA64E|27.778|1751.7 |-22
|
||||
|=====================================
|
||||
|
||||
[[FAST_MODES]]
|
||||
=== Fast Modes
|
||||
|
||||
==== ISCAT
|
||||
|
||||
ISCAT messages are free-form, up to 28 characters in length.
|
||||
Modulation is 42-tone frequency-shift keying at 11025 / 512 = 21.533
|
||||
baud (ISCAT-A), or 11025 / 256 = 43.066 baud (ISCAT-B). Tone
|
||||
frequencies are spaced by an amount in Hz equal to the baud rate. The
|
||||
available character set is:
|
||||
|
||||
----
|
||||
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ /.?@-
|
||||
----
|
||||
|
||||
Transmissions consist of sequences of 24 symbols: a synchronizing
|
||||
pattern of four symbols at tone numbers 0, 1, 3, and 2, followed by
|
||||
two symbols with tone number corresponding to (message length) and
|
||||
(message length + 5), and finally 18 symbols conveying the user's
|
||||
message, sent repeatedly character by character. The message always
|
||||
starts with `@`, the beginning-of-message symbol, which is not
|
||||
displayed to the user. The sync pattern and message-length indicator
|
||||
have a fixed repetition period, recurring every 24 symbols. Message
|
||||
information occurs periodically within the 18 symbol positions set
|
||||
aside for its use, repeating at its own natural length.
|
||||
|
||||
For example, consider the user message `CQ WA9XYZ`. Including the
|
||||
beginning-of-message symbol `@`, the message is 10 characters long.
|
||||
Using the character sequence displayed above to indicate tone numbers,
|
||||
the transmitted message will therefore start out as shown in the first
|
||||
line below:
|
||||
|
||||
----
|
||||
0132AF@CQ WA9XYZ@CQ WA9X0132AFYZ@CQ WA9XYZ@CQ W0132AFA9X ...
|
||||
sync## sync## sync##
|
||||
----
|
||||
|
||||
Note that the first six symbols (four for sync, two for message
|
||||
length) repeat every 24 symbols. Within the 18 information-carrying
|
||||
symbols in each 24, the user message `@CQ WA9XYZ` repeats at its own
|
||||
natural length, 10 characters. The resulting sequence is extended as
|
||||
many times as will fit into a Tx sequence.
|
||||
|
||||
==== JT9
|
||||
|
||||
The JT9 slow modes all use keying rate 12000/6912 = 1.736 baud. By contrast, with
|
||||
the *Fast* setting submodes JT9E-H adjust the keying rate to match the
|
||||
increased tone spacings. Message durations are therefore much
|
||||
shorter, and they are sent repeatedly throughout each Tx sequence.
|
||||
For details see Table 4, below.
|
||||
|
||||
==== MSK144
|
||||
|
||||
Standard MSK144 messages are structured in the same way as those in
|
||||
the slow modes, with 72 bits of user information. Forward error
|
||||
correction is implemented by first augmenting the 72 message bits with
|
||||
an 8-bit cyclic redundancy check (CRC) calculated from the message
|
||||
bits. The CRC is used to detect and eliminate most false decodes at
|
||||
the receiver. The resulting 80-bit augmented message is mapped to a
|
||||
128-bit codeword using a (128,80) binary low-density-parity-check
|
||||
(LDPC) code designed by K9AN specifically for this purpose. Two 8-bit
|
||||
synchronizing sequences are added to make a message frame 144 bits
|
||||
long. Modulation is Offset Quadrature Phase-Shift Keying (OQPSK) at
|
||||
2000 baud. Even-numbered bits are conveyed over the in-phase channel,
|
||||
odd-numbered bits on the quadrature channel. Individual symbols are
|
||||
shaped with half-sine profiles, thereby ensuring a generated waveform
|
||||
with constant envelope, equivalent to a Minimum Shift Keying (MSK)
|
||||
waveform. Frame duration is 72 ms, so the effective character
|
||||
transmission rate for standard messages is up to 250 cps.
|
||||
|
||||
Contest Mode in MSK144 conveys an additional acknowledgment bit (the
|
||||
"`R`" in a message of the form `W9XYZ K1ABC R FN42`) by using the fact
|
||||
that meteor scatter and other propagation modes usable with MSK144 are
|
||||
generally effective only out to distances of order 2500 km. To convey
|
||||
the message fragment `R FN42`, WSJT-X encodes the locator as that of
|
||||
its antipodes. The receiving program recognizes a locator with
|
||||
distance greater than 10,000 km, does the reverse transformation, and
|
||||
inserts the implied "`R`".
|
||||
|
||||
MSK144 also supports short-form messages that can be used after QSO
|
||||
partners have exchanged both callsigns. Short messages consist of 4
|
||||
bits encoding R+report, RRR, or 73, together with a 12-bit hash code
|
||||
based on the ordered pair of "`to`" and "`from`" callsigns. Another
|
||||
specially designed LDPC (32,16) code provides error correction, and an
|
||||
8-bit synchronizing vector is appended to make up a 40-bit frame.
|
||||
Short-message duration is thus 20 ms, and short messages can be
|
||||
decoded from very short meteor pings.
|
||||
|
||||
The 72 ms or 20 ms frames of MSK144 messages are repeated without gaps
|
||||
for the full duration of a transmission cycle. For most purposes, a
|
||||
cycle duration of 15 s is suitable and recommended for MSK144.
|
||||
|
||||
The modulated MSK144 signal occupies the full bandwidth of a SSB
|
||||
transmitter, so transmissions are always centered at audio frequency
|
||||
1500 Hz. For best results, transmitter and receiver filters should be
|
||||
adjusted to provide the flattest possible response over the range
|
||||
300Hz to 2700Hz. The maximum permissible frequency offset between you
|
||||
and your QSO partner ± 200 Hz.
|
||||
|
||||
==== Summary
|
||||
|
||||
.Parameters of Fast Modes
|
||||
[width="90%",cols="3h,^3,^2,^1,^2,^2,^2,^2,^2",frame="topbot",options="header"]
|
||||
|=====================================================================
|
||||
|Mode |FEC Type |(n,k) | Q|Modulation Type|Keying rate (Baud)
|
||||
|Bandwidth (Hz)|Sync Energy|Tx Duration (s)
|
||||
|ISCAT-A | - | - |42|42-FSK| 21.5 | 905 | 0.17| 1.176
|
||||
|ISCAT-B | - | - |42|42-FSK| 43.1 | 1809 | 0.17| 0.588
|
||||
|JT9E |K=32, r=1/2|(206,72)| 8| 9-FSK| 25.0 | 225 | 0.19| 3.400
|
||||
|JT9F |K=32, r=1/2|(206,72)| 8| 9-FSK| 50.0 | 450 | 0.19| 1.700
|
||||
|JT9G |K=32, r=1/2|(206,72)| 8| 9-FSK|100.0 | 900 | 0.19| 0.850
|
||||
|JT9H |K=32, r=1/2|(206,72)| 8| 9-FSK|200.0 | 1800 | 0.19| 0.425
|
||||
|MSK144 |LDPC |(128,80)| 2| OQPSK| 2000 | 2400 | 0.11| 0.072
|
||||
|MSK144 Sh|LDPC |(32,16) | 2| OQPSK| 2000 | 2400 | 0.20| 0.020
|
||||
|=====================================================================
|
||||
Reference in New Issue
Block a user