VO1NA wrote:
> Stefan has suggested a longer CRC might be helpful.
> Should I give this a try?
Worth a try. One advantage: if you only have one or two
characters to send, with say 8 bit CRC, the Viterbi payload
is only 20 bits which doesn't make for a strong coding.
By using a longer CRC you can pad this out, eg to 36 bits.
This means you can use a stronger coding eg 16K23A, plus there
is more discrimination (in terms of path metric) in the
Viterbi layer between real and false hits. Also you may choose
to use less than optimum list length to get less chance of
a false decode.
> Have the daytime transmissions been decoded?
Daytime signal is received well in UK but not so good in Europe.
Some days carrier was sent instead of EbNaut. *Carrier* indicates
the '*' message decoded from the carrier with the same message
settings.
Todmorden (3575 km)
-------------------
10 Eb/N0 11.6 dB, S/N -26.0 dB/1Hz, phase -74.7 *Decoded*
11 Eb/N0 7.0 dB, S/N -30.6 dB/1Hz, phase -76.6 *Decoded*
12 Eb/N0 -3.2 dB, S/N -40.8 dB/1Hz, phase 83.8;
13 Eb/N0 -5.3 dB, S/N -42.8 dB/1Hz, phase -86.7;
14 Eb/N0 -6.3 dB, S/N -44.0 dB/1Hz, phase -107.5;
15 Eb/N0 +7.9 dB, S/N -29.6 dB/1Hz, phase 105.4 *Carrier*
16 Eb/N0 -4.3 dB, S/N -41.9 dB/1Hz, phase 139.5;
17 Eb/N0 +7.6 dB, S/N -30.0 dB/1Hz, phase 122.7 *Carrier*
18 Eb/N0 +2.9 dB, S/N -34.7 dB/1Hz, phase 85.7 *Carrier*
19 Eb/N0 +9.3 dB, S/N -28.3 dB/1Hz, phase 117.9 *Carrier*
20 Eb/N0 +10.9 dB, S/N -26.7 dB/1Hz, phase 112.1 *Carrier*
21 Eb/N0 +10.1 dB, S/N -27.5 dB/1Hz, phase -63.4 *Decoded*
22 Eb/N0 +0.2 dB, S/N -37.3 dB/1Hz, phase -73.3 *Decoded*
23 Eb/N0 +7.0 dB, S/N -30.6 dB/1Hz, phase -55.4 *Decoded*
24 Eb/N0 +3.2 dB, S/N -34.3 dB/1Hz, phase -53.5 *Decoded*
25 Eb/N0 +9.6 dB, S/N -28.0 dB/1Hz, phase -73.4 *Decoded*
26 Eb/N0 +15.3 dB, S/N -22.3 dB/1Hz, phase -91.1 *Decoded*
27 Eb/N0 +8.8 dB, S/N -28.8 dB/1Hz, phase -75.1 *Decoded*
28 Eb/N0 +8.3 dB, S/N -29.3 dB/1Hz, phase -82.1 *Decoded*
29 Eb/N0 +10.2 dB, S/N -27.4 dB/1Hz, phase -96.4 *Decoded*
Bielefeld (4301.5 km DL4YHF)
----------------------------
10 Eb/N0 -1.1 dB, S/N -38.6 dB/1Hz, phase 122.9;
11 Eb/N0 +1.7 dB, S/N -35.9 dB/1Hz, phase 70.2 *Decoded*
12 Eb/N0 -8.1 dB, S/N -64.4 dB/1Hz;
13 Eb/N0 -10.4 dB, S/N -48.0 dB/1Hz;
14 Eb/N0 -11.2 dB, S/N -48.8 dB/1Hz;
15 Eb/N0 -13.2 dB, S/N -50.8 dB/1Hz, phase -22.0;
16 Eb/N0 -10.4 dB, S/N -48.0 dB/1Hz;
17 Eb/N0 -3.2 dB, S/N -40.8 dB/1Hz, phase -77.6;
18 Eb/N0 -14.8 dB, S/N -52.4 dB/1Hz, phase 27.2;
19 Eb/N0 -0.6 dB, S/N -38.1 dB/1Hz, phase -16.8;
20 Eb/N0 -2.8 dB, S/N -40.4 dB/1Hz, phase -9.6;
21 Eb/N0 -10.5 dB, S/N -48.0 dB/1Hz;
22 Eb/N0 -6.5 dB, S/N -44.1 dB/1Hz, phase -49.3;
23 Eb/N0 -14.3 dB, S/N -51.9 dB/1Hz;
24 Eb/N0 -16.7 dB, S/N -54.3 dB/1Hz;
25 Eb/N0 -10.8 dB, S/N -48.3 dB/1Hz, phase 28.8;
26 Eb/N0 -3.1 dB, S/N -40.7 dB/1Hz, phase 85.4;
27 Eb/N0 -2.2 dB, S/N -39.8 dB/1Hz, phase 85.7;
28 Eb/N0 -5.1 dB, S/N -42.7 dB/1Hz, phase 125.9;
29 Eb/N0 -4.7 dB, S/N -42.3 dB/1Hz, phase 113.2;
Cumiana (4533.4 km IK1QFK)
--------------------------
10 Eb/N0 -5.0 dB, S/N -42.6 dB/1Hz, phase -6.4;
11 Eb/N0 -4.7 dB, S/N -42.3 dB/1Hz, phase 90.1;
12 Eb/N0 -14.5 dB, S/N -52.0 dB/1Hz;
13 Eb/N0 -3.3 dB, S/N -40.9 dB/1Hz, phase 177.7;
14 Eb/N0 -1.8 dB, S/N -39.4 dB/1Hz, phase -50.4;
15 Eb/N0 -4.4 dB, S/N -42.0 dB/1Hz, phase -133.6;
16 Eb/N0 -3.9 dB, S/N -41.5 dB/1Hz, phase -96.2;
17 Eb/N0 -3.3 dB, S/N -40.9 dB/1Hz, phase -120.5;
18 Eb/N0 -2.8 dB, S/N -40.4 dB/1Hz, phase -153.7;
19 Eb/N0 -3.5 dB, S/N -41.1 dB/1Hz, phase -83.3;
20 Eb/N0 -6.7 dB, S/N -44.2 dB/1Hz, phase -121.3;
21 Eb/N0 -0.5 dB, S/N -38.1 dB/1Hz, phase -73.0;
22 Eb/N0 -7.2 dB, S/N -44.8 dB/1Hz, phase -95.5;
23 Eb/N0 -7.8 dB, S/N -45.4 dB/1Hz, phase 68.5;
24 Eb/N0 -16.1 dB, S/N -53.7 dB/1Hz;
25 Eb/N0 -22.7 dB, S/N -60.3 dB/1Hz;
26 Eb/N0 +1.7 dB, S/N -35.9 dB/1Hz, phase 114.7 *Decoded*
27 Eb/N0 -13.5 dB, S/N -51.1 dB/1Hz;
28 Eb/N0 -3.1 dB, S/N -40.7 dB/1Hz, phase 79.2;
29 Eb/N0 -8.8 dB, S/N -46.4 dB/1Hz, phase 159.8;
Forest, VA (2415.3 km KE4RJQ)
-----------------------------
10 Eb/N0 -1.0 dB, S/N -38.6 dB/1Hz, phase -23.2;
11 Eb/N0 -6.0 dB, S/N -43.6 dB/1Hz, phase -39.7;
12 Eb/N0 -1.5 dB, S/N -39.0 dB/1Hz, phase -126.5;
13 Eb/N0 -3.1 dB, S/N -40.7 dB/1Hz, phase 60.3;
14 Eb/N0 -7.1 dB, S/N -44.7 dB/1Hz, phase -147.7;
15 Eb/N0 -26.4 dB, S/N -64.0 dB/1Hz;
16 Eb/N0 -6.8 dB, S/N -44.4 dB/1Hz, phase 131.4;
17 Eb/N0 -12.4 dB, S/N -50.0 dB/1Hz;
18 Eb/N0 -5.5 dB, S/N -43.1 dB/1Hz, phase 154.8;
19 Eb/N0 -4.7 dB, S/N -42.3 dB/1Hz, phase 178.6;
20 Eb/N0 -18.2 dB, S/N -55.8 dB/1Hz;
21 Eb/N0 -6.1 dB, S/N -43.7 dB/1Hz, phase -65.9;
22 Eb/N0 -5.6 dB, S/N -43.2 dB/1Hz, phase -135.4;
23 Eb/N0 -3.7 dB, S/N -41.3 dB/1Hz, phase -34.7;
24 Eb/N0 -4.6 dB, S/N -42.1 dB/1Hz, phase -140.0;
25 Eb/N0 -10.8 dB, S/N -48.4 dB/1Hz, phase -44.5;
26 Eb/N0 -5.3 dB, S/N -42.8 dB/1Hz, phase 19.7;
27 Eb/N0 -4.2 dB, S/N -41.8 dB/1Hz, phase 28.7;
28 Eb/N0 -6.3 dB, S/N -43.9 dB/1Hz, phase 141.2;
29 Eb/N0 -3.4 dB, S/N -40.9 dB/1Hz, phase -103.9;
Hawley, TX (4240.3 km)
----------------------
10 Eb/N0 -23.4 dB, S/N -61.0 dB/1Hz;
11 Eb/N0 -3.8 dB, S/N -41.4 dB/1Hz, phase -135.5;
12 Eb/N0 -7.4 dB, S/N -45.0 dB/1Hz, phase 66.3;
13 Eb/N0 -3.8 dB, S/N -41.4 dB/1Hz, phase -72.7;
14 Eb/N0 -14.8 dB, S/N -52.4 dB/1Hz;
15 Eb/N0 -16.1 dB, S/N -53.7 dB/1Hz;
16 Eb/N0 -5.8 dB, S/N -43.4 dB/1Hz, phase 92.2;
17 Eb/N0 -0.7 dB, S/N -38.3 dB/1Hz, phase 5.1;
18 Eb/N0 -7.0 dB, S/N -44.6 dB/1Hz, phase -128.4;
19 Eb/N0 -8.9 dB, S/N -46.5 dB/1Hz, phase 13.6;
20 Eb/N0 -6.8 dB, S/N -44.4 dB/1Hz, phase -172.5;
21 Eb/N0 -4.2 dB, S/N -41.8 dB/1Hz, phase 162.0;
22 Eb/N0 -8.5 dB, S/N -46.0 dB/1Hz, phase 111.8;
23 Eb/N0 -11.6 dB, S/N -49.1 dB/1Hz;
24 Eb/N0 -4.1 dB, S/N -41.7 dB/1Hz, phase 170.9;
25 Eb/N0 -3.0 dB, S/N -40.5 dB/1Hz, phase -118.8;
26 Eb/N0 No uplink;
27 Eb/N0 -0.7 dB, S/N -38.3 dB/1Hz, phase 179.2;
28 Eb/N0 -3.7 dB, S/N -41.3 dB/1Hz, phase -119.7;
29 Eb/N0 -5.3 dB, S/N -42.8 dB/1Hz, phase 41.5;
--
Paul Nicholson
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