From 2051bf3cb6ec3a164651cc5e3018d2c5f49fc7ca Mon Sep 17 00:00:00 2001 From: drowe67 Date: Thu, 15 Oct 2015 03:32:43 +0000 Subject: [PATCH] fixed phase discontnuity in simulated fsk tx git-svn-id: https://svn.code.sf.net/p/freetel/code@2443 01035d8c-6547-0410-b346-abe4f91aad63 --- codec2-dev/octave/crc16.m | 55 ++++++++++++++++++++++++++++ codec2-dev/octave/fsk_horus.m | 41 ++++++++++++++++----- codec2-dev/octave/fsk_horus_stream.m | 5 ++- 3 files changed, 90 insertions(+), 11 deletions(-) create mode 100644 codec2-dev/octave/crc16.m diff --git a/codec2-dev/octave/crc16.m b/codec2-dev/octave/crc16.m new file mode 100644 index 00000000..aafc432f --- /dev/null +++ b/codec2-dev/octave/crc16.m @@ -0,0 +1,55 @@ +% crc16.m +% +%The CRC calculation is based on following generator polynomial: +%G(x) = x16 + x12 + x5 + 1 +% +%The register initial value of the implementation is: 0xFFFF +% +%used data = string -> 1 2 3 4 5 6 7 8 9 +% +% Online calculator to check the script: +%http://www.lammertbies.nl/comm/info/crc-calculation.html +% +% + +function crc = crc16(data) + + % crc look up table + + Crc_ui16LookupTable=[0,4129,8258,12387,16516,20645,24774,28903,33032,37161,41290,45419,49548,... + 53677,57806,61935,4657,528,12915,8786,21173,17044,29431,25302,37689,33560,45947,41818,54205,... + 50076,62463,58334,9314,13379,1056,5121,25830,29895,17572,21637,42346,46411,34088,38153,58862,... + 62927,50604,54669,13907,9842,5649,1584,30423,26358,22165,18100,46939,42874,38681,34616,63455,... + 59390,55197,51132,18628,22757,26758,30887,2112,6241,10242,14371,51660,55789,59790,63919,35144,... + 39273,43274,47403,23285,19156,31415,27286,6769,2640,14899,10770,56317,52188,64447,60318,39801,... + 35672,47931,43802,27814,31879,19684,23749,11298,15363,3168,7233,60846,64911,52716,56781,44330,... + 48395,36200,40265,32407,28342,24277,20212,15891,11826,7761,3696,65439,61374,57309,53244,48923,... + 44858,40793,36728,37256,33193,45514,41451,53516,49453,61774,57711,4224,161,12482,8419,20484,... + 16421,28742,24679,33721,37784,41979,46042,49981,54044,58239,62302,689,4752,8947,13010,16949,... + 21012,25207,29270,46570,42443,38312,34185,62830,58703,54572,50445,13538,9411,5280,1153,29798,... + 25671,21540,17413,42971,47098,34713,38840,59231,63358,50973,55100,9939,14066,1681,5808,26199,... + 30326,17941,22068,55628,51565,63758,59695,39368,35305,47498,43435,22596,18533,30726,26663,6336,... + 2273,14466,10403,52093,56156,60223,64286,35833,39896,43963,48026,19061,23124,27191,31254,2801,6864,... + 10931,14994,64814,60687,56684,52557,48554,44427,40424,36297,31782,27655,23652,19525,15522,11395,... + 7392,3265,61215,65342,53085,57212,44955,49082,36825,40952,28183,32310,20053,24180,11923,16050,3793,7920]; + + ui16RetCRC16 = hex2dec('FFFF'); + for I=1:length(data) + ui8LookupTableIndex = bitxor(data(I),uint8(bitshift(ui16RetCRC16,-8))); + ui16RetCRC16 = bitxor(Crc_ui16LookupTable(double(ui8LookupTableIndex)+1),mod(bitshift(ui16RetCRC16,8),65536)); + end + crc=dec2hex(ui16RetCRC16); + +endfunction + + + + + + + + + + + + diff --git a/codec2-dev/octave/fsk_horus.m b/codec2-dev/octave/fsk_horus.m index 1d9ec521..3ca303fe 100644 --- a/codec2-dev/octave/fsk_horus.m +++ b/codec2-dev/octave/fsk_horus.m @@ -302,22 +302,41 @@ endfunction % Extract ASCII string from a Horus frame of bits -function str = extract_ascii(states, rx_bits_buf, uw_loc1, uw_loc2) +function [str crc_ok] = extract_ascii(states, rx_bits_buf, uw_loc1, uw_loc2) nfield = states.nfield; npad = states.npad; - str = []; + str = []; str_dec = []; nstr = 0; st = uw_loc1 + length(states.uw); % first bit of first char for i=st:nfield+npad:uw_loc2 field = rx_bits_buf(i:i+nfield-1); ch_dec = field * (2.^(0:nfield-1))'; - + % filter out unlikely characters that bit errors may introduce, and ignore \n + if (ch_dec > 31) && (ch_dec < 91) str = [str char(ch_dec)]; else str = [str char(32)]; % space is "not sure" end + nstr++; + + % build up array for CRC16 check + + if ch_dec == 42 + rx_crc = crc16(str_dec); + ptx_crc = nstr+1; + else + str_dec = [str_dec ch_dec]; + end + end + tx_crc = str(ptx_crc:ptx_crc+3); + crc_ok = strcmp(tx_crc, rx_crc); + str = str(1:ptx_crc-2); + if crc_ok + str = sprintf("%s CRC OK", str); + else + str = sprintf("%s CRC BAD", str); end endfunction @@ -367,7 +386,7 @@ function run_sim test_frame_mode = 4; fading = 1; % modulates tx power at 2Hz with 20dB fade depth, % to simulate balloon rotating at end of mission - df = 1; % tx tone freq drift in Hz/s + df = 0; % tx tone freq drift in Hz/s more off rand('state',1); @@ -637,9 +656,11 @@ endfunction % run test functions from here during development -run_sim -%rx_bits = demod_file("~/Desktop/vk5arg-3-1.wav"); -%rx_bits = demod_file("~/Desktop/fsk_horus_10dB_1000ppm.wav"); -%rx_bits = demod_file("~/Desktop/fsk_horus_6dB_0ppm.wav"); -%rx_bits = demod_file("fsk_horus_rx.raw"); -%rx_bits = demod_file("~/Desktop/fsk_horus_20dB_0ppm_20dBfade.wav"); +if exist("fsk_horus_as_a_lib") == 0 + run_sim + %rx_bits = demod_file("~/Desktop/vk5arg-3-1.wav"); + %rx_bits = demod_file("~/Desktop/fsk_horus_10dB_1000ppm.wav"); + %rx_bits = demod_file("~/Desktop/fsk_horus_6dB_0ppm.wav"); + %rx_bits = demod_file("fsk_horus_rx.raw"); + %rx_bits = demod_file("~/Desktop/fsk_horus_20dB_0ppm_20dBfade.wav"); +end diff --git a/codec2-dev/octave/fsk_horus_stream.m b/codec2-dev/octave/fsk_horus_stream.m index 9cf07fe0..5355d32d 100644 --- a/codec2-dev/octave/fsk_horus_stream.m +++ b/codec2-dev/octave/fsk_horus_stream.m @@ -14,7 +14,10 @@ % $ cat ~/Desktop/vk5arg-3.wav | ./fsk_horus_stream.m % -fsk_horus; % include library (make sure calls to functions at bottom are commented out) +% include library (make sure calls to test functions at bottom are disabled) + +fsk_horus_as_a_lib = 1; +fsk_horus; more off; states = fsk_horus_init(); -- 2.25.1