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Vladimir Fadeev
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documentation is corrected
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ModulationPy/ModulationPy.py

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@@ -352,7 +352,9 @@ def __qam_symbols(self):
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return s
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def __gray_qam_arange(self):
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""" Rearanges complex coordinates according to Gray coding requirements.
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""" This method re-arranges complex coordinates according to Gray coding requirements.
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To implement correct Gray mapping the additional heuristic is used:
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the even "columns" in the signal constellation is complex conjugated.
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"""
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for idx, (key, item) in enumerate(self.code_book.items()):

README.md

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@@ -96,13 +96,9 @@ M-QAM modem is available in ```class QAMModem``` with the following parameters:
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| ```soft_decision``` | ```True``` or ```False``` | Specify whether the output values of ```demodulate()``` method is demodulated as hard or soft decisions. If parametr is ```True``` the output will be Log-likelihood ratios (LLR's), else binary symbols. The default is ```True```.|
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| ```bin_output``` | ```True``` or ```False```|Specify whether the output of ```demodulate()``` method is bits or integers. The default is ```True```.|
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Now the QAM modulation is designed as in **qammod** Octave function \[4\]. It requires only "even" (in sense, that ```log2(M)``` is even) modulation schemes (4-QAM, 16-QAM, 64-QAM and so on).
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Now the QAM modulation is designed as in **qammod** Octave function \[4\]. It requires only "even" (in sense, that ```log2(M)``` is even) modulation schemes (4-QAM, 16-QAM, 64-QAM and so on - universal and simple).
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Anyway, there are no "odd" modulation schemes in [popular wireless communication standards](https://www.quora.com/What-different-modulation-techniques-are-used-in-1G-2G-3G-4G-and-5G).
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Actually, this fact has its own reasons:
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- the modulation algorithm for these modulation schemes is universal and simple;
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- there are no "odd" modulation schemes in [popular wireless communication standards](https://www.quora.com/What-different-modulation-techniques-are-used-in-1G-2G-3G-4G-and-5G).
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To implement correct Gray mapping the additional heuristic is used: the even "columns" in the signal constellation is complex conjugated.
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## How to use?
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