From 0415103f1698fe6855720b3b33d6b6b0bd4a2fd2 Mon Sep 17 00:00:00 2001 From: Bill Somerville Date: Sun, 13 Aug 2017 23:37:16 +0000 Subject: [PATCH] Merged from trunk: ------------------------------------------------------------------------ r8020 | k9an | 2017-08-10 03:51:25 +0100 (Thu, 10 Aug 2017) | 1 line Correct misspelling. Thanks Seb, W4AS. ------------------------------------------------------------------------ r8021 | bsomervi | 2017-08-10 19:07:53 +0100 (Thu, 10 Aug 2017) | 1 line Fix FT8 encoding description ------------------------------------------------------------------------ git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx-1.8@8025 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 --- Configuration.ui | 2 +- doc/user_guide/en/protocols.adoc | 16 ++++++++-------- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/Configuration.ui b/Configuration.ui index dfcb6b110..ba467b976 100644 --- a/Configuration.ui +++ b/Configuration.ui @@ -1820,7 +1820,7 @@ for assessing propagation and system performance. - See WSPR documentattion Appendix C for details of how to determine these factors for your radio. + See WSPR documentation Appendix C for details of how to determine these factors for your radio. Frequency Calibration diff --git a/doc/user_guide/en/protocols.adoc b/doc/user_guide/en/protocols.adoc index 3ccf00ec9..b302aa34a 100644 --- a/doc/user_guide/en/protocols.adoc +++ b/doc/user_guide/en/protocols.adoc @@ -61,15 +61,15 @@ _WSJT-X_ modes have continuous phase and constant envelope. [[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 +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 87 parity bits making a 174-bit codeword. 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. +symbols is 174/3 + 21 = 79. The total occupied bandwidth is 8 × 6.25 += 50 Hz. [[JT4PRO]] ==== JT4