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meh.

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John Greb 2015-03-24 11:00:38 +00:00
parent a05759e1b8
commit 6534d1dd4d
1 changed files with 3 additions and 4 deletions
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7
plugins/channel/lora/lorabits.h
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@ -5,10 +5,9 @@
More spreading needs higher frequency resolution and longer time on air, increasing drift errors. More spreading needs higher frequency resolution and longer time on air, increasing drift errors.
Want higher bandwidth when using more spreading, which needs more CPU and a better FFT. Want higher bandwidth when using more spreading, which needs more CPU and a better FFT.
Six bit Hamming can only correct drift errors. Need 7 or 8 bit FEC for QRM Six bit Hamming can only correct long runs of drift errors when not using interleaving. Interleaving defeats the point of using Gray code and puts multiple bit errors into single FEC blocks. Hardware decoding uses RSSI to detect the symbols most likely to be damaged, so that individual bits can be repaired after de-interleaving.
Easier to use 5:4 FEC with Reed-Soloman messages.
Implicit Mode: explicit starts with a 4:8 block and has different whitening Using Implicit Mode: explicit starts with a 4:8 block and seems to have a different whitening sequence.
*/ */
// Six bits per symbol, six chars per block // Six bits per symbol, six chars per block
@ -39,7 +38,7 @@ short LoRaDemod::toGray(short num)
return (num >> 1) ^ num; return (num >> 1) ^ num;
} }
// ignore FEC, try to extract raw bits // Ignore the FEC bits, just extract the data bits
void LoRaDemod::hamming6(char* c, int size) void LoRaDemod::hamming6(char* c, int size)
{ {
int i; int i;