Updates to the User Guide, mostly related to addition of the FT4 mode.

This commit is contained in:
Joe Taylor 2019-06-06 13:44:32 -04:00
parent 9c3c5d6b3c
commit e3c73def7a
5 changed files with 56 additions and 59 deletions

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@ -116,6 +116,7 @@ d). Edit lines as needed. Keeping them in alphabetic order help see dupes.
:QRA64_EME: http://physics.princeton.edu/pulsar/K1JT/QRA64_EME.pdf[QRA64 for microwave EME]
:svn: http://subversion.apache.org/packages.html#windows[Subversion]
:win32: http://physics.princeton.edu/pulsar/K1JT/wsjtx-{VERSION}-win32.exe[wsjtx-{VERSION}-win32.exe]
:win64: http://physics.princeton.edu/pulsar/K1JT/wsjtx-{VERSION}-win64.exe[wsjtx-{VERSION}-win64.exe]
:wsjt-devel: https://lists.sourceforge.net/lists/listinfo/wsjt-devel[here]
:wsjt_repo: https://sourceforge.net/p/wsjt/wsjt_orig/ci/master/tree/[WSJT Source Repository]
:wspr_code: http://physics.princeton.edu/pulsar/K1JT/WSPRcode.exe[WSPRcode.exe]

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@ -1,11 +1,12 @@
// Status=review
Download and execute the package file {win32}, following these
instructions:
Download and execute the package file {win32} (WinXP, Vista, Win 7,
Win 8, Win10, 32-bit) or {win64} (Vista, Win 7, Win 8, Win10, 64-bit)
following these instructions:
* Install _WSJT-X_ into its own directory, for example `C:\WSJTX` or `
C:\WSJT\WSJTX`, rather than the conventional location `C:\Program
Files (x86)\WSJTX`.
Files ...\WSJTX`.
* All program files relating to _WSJT-X_ will be stored in the chosen
installation directory and its subdirectories.

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@ -7,10 +7,10 @@ K1**JT**,`" while the suffix "`-X`" indicates that _WSJT-X_ started as
an extended and experimental branch of the program
_WSJT_.
_WSJT-X_ Version {VERSION_MAJOR}.{VERSION_MINOR} offers nine different
protocols or modes: *FT8*, *JT4*, *JT9*, *JT65*, *QRA64*, *ISCAT*,
*MSK144*, *WSPR*, and *Echo*. The first five are designed for making
reliable QSOs under extreme weak-signal conditions. They use nearly
_WSJT-X_ Version {VERSION_MAJOR}.{VERSION_MINOR} offers ten different
protocols or modes: *FT4*, *FT8*, *JT4*, *JT9*, *JT65*, *QRA64*,
*ISCAT*, *MSK144*, *WSPR*, and *Echo*. The first six are designed for
making reliable QSOs under weak-signal conditions. They use nearly
identical message structure and source encoding. JT65 and QRA64 were
designed for EME ("`moonbounce`") on the VHF/UHF bands and have also
proven very effective for worldwide QRP communication on the HF bands.
@ -25,12 +25,17 @@ one-minute timed sequences of alternating transmission and reception,
so a minimal QSO takes four to six minutes — two or three
transmissions by each station, one sending in odd UTC minutes and the
other even. FT8 is operationally similar but four times faster
(15-second T/R sequences) and less sensitive by a few dB. On the HF
bands, world-wide QSOs are possible with any of these modes using
power levels of a few watts (or even milliwatts) and compromise
antennas. On VHF bands and higher, QSOs are possible (by EME and
other propagation types) at signal levels 10 to 15 dB below those
required for CW.
(15-second T/R sequences) and less sensitive by a few dB. FT4 is
faster still (7.5 s T/R sequences) and especially well suited for
radio contesting. On the HF bands, world-wide QSOs are possible with
any of these modes using power levels of a few watts (or even
milliwatts) and compromise antennas. On VHF bands and higher, QSOs
are possible (by EME and other propagation types) at signal levels 10
to 15 dB below those required for CW.
Note that even though their T/R sequences are short, FT4 and FT8 are
classified as slow modes because their message frames are sent
only once per transmission.
*ISCAT*, *MSK144*, and optionally submodes *JT9E-H* are "`fast`"
protocols designed to take advantage of brief signal enhancements from
@ -65,10 +70,10 @@ are available for all three platforms.
*Version Numbers:* _WSJT-X_ release numbers have major, minor, and
patch numbers separated by periods: for example, _WSJT-X_ Version
1.9.0. Temporary "`beta`" release candidates are sometimes made in
2.1.0. Temporary _beta release_ candidates are sometimes made in
advance of a new general-availability release, in order to obtain user
feedback. For example, version 1.9.0-rc1, 1.9.0-rc2, etc., would
be beta releases leading up to the final release of v1.9.0.
feedback. For example, version 2.1.0-rc1, 2.1.0-rc2, etc., would
be beta releases leading up to the final release of v2.1.0.
Release candidates should be used _only_ during a short testing
period. They carry an implied obligation to provide feedback to the
program development group. Candidate releases should not be used on

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@ -1,40 +1,17 @@
=== New in Version {VERSION}
For quick reference, here's a short list of features and capabilities
added to _WSJT-X_ since Version 1.9.1:
added to _WSJT-X_ since Version 2.0.1:
- New FT8 and MSK144 protocols with 77-bit payloads permit these enhancements:
- New FT4 protocol, designed especially for radio contesting
* Optimized contest messages for NA VHF, EU VHF, Field Day, RTTY Roundup
* T/R sequence length 7.5 s
* Full support for "/R" and "/P" calls in relevant contests
* Bandwidth 80 Hz
* New logging features for contesting
* Integration with {n1mm_logger} and {writelog} for contesting
* Improved support for compound and nonstandard callsigns
* Nearly equal (or better) sensitivity compared to old protocols
* Lower false decode rates
- Improved color highlighting of received messages
- Improved WSPR sensitivity
- Expanded and improved UDP messages sent to companion programs
- Bug fixes and other minor tweaks to user interface
IMPORTANT: Note that for FT8 and MSK144 there is no backward
compatibility with WSJT-X 1.9.1 and earlier. Everyone using these
modes should upgrade to WSJT-X 2.0 by January 1, 2019.
IMPORTANT: _WSJT-X_ Version 2.0 drops support for Apple Mac OS X 10.9
(Mavericks). It is possible to build from source for this operating
system version but the DMG installer package requires 10.10 or later.
* Threshold sensitivity -17.5 dB
- Improvements to accessibility
=== Documentation Conventions

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@ -12,10 +12,10 @@ Special cases allow other information such as add-on callsign prefixes
aim is to compress the most common messages used for minimally valid
QSOs into a fixed 72-bit length.
The information payload for FT8 and MSK144 contains 77 bits. The 5
additional bits are used to flag special message types used for FT8
DXpedition Mode, contesting, nonstandard callsigns, and a few other
special types.
The information payload for FT4, FT8, and MSK144 contains 77 bits.
The 5 additional bits are used to flag special message types used for
FT8 DXpedition Mode, contesting, nonstandard callsigns, and a few
other special types.
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
@ -67,18 +67,29 @@ _WSJT-X_ modes have continuous phase and constant envelope.
[[SLOW_MODES]]
=== Slow Modes
[[FT4PRO]]
==== FT4
Forward error correction (FEC) in FT4 uses a low-density parity check
(LDPC) code with 77 information bits, a 14-bit cyclic redundancy check
(CRC), and 83 parity bits making a 174-bit codeword. It is thus
called an LDPC (174,91) code. Synchronization uses four 4×4 Costas
arrays, and ramp-up and ramp-down symbols are inserted at the start
and end of each transmission. Modulation is 4-tone frequency-shift
keying with Gaussian smoothing of frequency transitions (4-GFSK). The
keying rate is 12000/576 = 20.8333 baud. Each transmitted symbol
conveys two bits, so the total number of channel symbols is 174/2 + 16
+ 2 = 105. The total bandwidth is 4 × 20.8333 = 83.3 Hz.
[[FT8PRO]]
==== FT8
Forward error correction (FEC) in FT8 uses a low-density parity check
(LDPC) code with 77 information bits, a 14-bit cyclic redundancy check
(CRC), and 83 parity bits making a 174-bit codeword. It is thus
called an LDPC (174,91) 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.
FT8 uses the same LDPC (174,91) code as FT4. Modulation is 8-tone
frequency-shift keying (8-GFSK) at 12000/1920 = 6.25 baud.
Synchronization uses 7×7 Costas arrays at the beginning, middle, and
end of each transmission. Transmitted symbols carry 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
@ -227,7 +238,8 @@ which the probability of decoding is 50% or higher.
|===============================================================================
|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|(174,91)| 8| 8-FSK| 6.25 | 50.0 | 0.27| 12.6 | -21
|FT4 |LDPC, r=1/2|(174,91)| 4| 4-GFSK| 20.8333 | 83.3 | 0.15| 5.04 | -17.5
|FT8 |LDPC, r=1/2|(174,91)| 8| 8-GFSK| 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
@ -246,6 +258,7 @@ comparable to tone spacing.
[width="50%",cols="h,3*^",frame=topbot,options="header"]
|=====================================
|Mode |Tone Spacing |BW (Hz)|S/N (dB)
|FT4 |20.8333 | 83.3 |-17.5
|FT8 |6.25 | 50.0 |-21
|JT4A |4.375| 17.5 |-23
|JT4B |8.75 | 30.6 |-22