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26 lines
624 B
C
26 lines
624 B
C
/*
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Interleaving is "easiest" if the same number of bits is used per symbol as for FEC
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Chosen mode "spreading 8, low rate" has 6 bits per symbol, so use 4:6 FEC
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*/
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// Needs adjusting for different sizes
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void LoRaDemod::interleave(char* inout)
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{
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int i, index = 6;
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char in[index * 2];
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for (i = 0; i < index; i++)
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in[i] = inout[i];
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// top bits are swapped ?
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for (i = 0; i < index; i++) {
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inout[i] = (32 & in[1 + i]) | (16 & in[0 + i]) | (8 & in[2 + i])
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| (4 & in[3 + i]) | (2 & in[4 + i]) | (1 & in[5 + i]);
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in[i + index] = in[i];
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}
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}
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short LoRaDemod::toGray(short num)
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{
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return (num >> 1) ^ num;
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}
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