mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-14 12:22:00 -05:00
80 lines
2.9 KiB
C++
80 lines
2.9 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
|
|
// Copyright (C) 2024 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
|
|
// //
|
|
// This is the code from ft8mon: https://github.com/rtmrtmrtmrtm/ft8mon //
|
|
// reformatted and adapted to Qt and SDRangel context //
|
|
// //
|
|
// This program is free software; you can redistribute it and/or modify //
|
|
// it under the terms of the GNU General Public License as published by //
|
|
// the Free Software Foundation as version 3 of the License, or //
|
|
// (at your option) any later version. //
|
|
// //
|
|
// This program is distributed in the hope that it will be useful, //
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
|
|
// GNU General Public License V3 for more details. //
|
|
// //
|
|
// You should have received a copy of the GNU General Public License //
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
|
|
///////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#ifndef _ft8stats_h_
|
|
#define _ft8stats_h_
|
|
|
|
#include <vector>
|
|
|
|
#include "export.h"
|
|
|
|
namespace FT8 {
|
|
//
|
|
// manage statistics for soft decoding, to help
|
|
// decide how likely each symbol is to be correct,
|
|
// to drive LDPC decoding.
|
|
//
|
|
// meaning of the how (problt_how) parameter:
|
|
// 0: gaussian
|
|
// 1: index into the actual distribution
|
|
// 2: do something complex for the tails.
|
|
// 3: index into the actual distribution plus gaussian for tails.
|
|
// 4: similar to 3.
|
|
// 5: laplace
|
|
//
|
|
class FT8_API Stats
|
|
{
|
|
public:
|
|
std::vector<float> a_;
|
|
float sum_;
|
|
bool finalized_;
|
|
float mean_; // cached
|
|
float stddev_; // cached
|
|
float b_; // cached
|
|
int how_;
|
|
|
|
public:
|
|
Stats(int how, float log_tail, float log_rate);
|
|
void add(float x);
|
|
void finalize();
|
|
float mean();
|
|
float stddev();
|
|
|
|
// fraction of distribution that's less than x.
|
|
// assumes normal distribution.
|
|
// this is PHI(x), or the CDF at x,
|
|
// or the integral from -infinity
|
|
// to x of the PDF.
|
|
float gaussian_problt(float x);
|
|
// https://en.wikipedia.org/wiki/Laplace_distribution
|
|
// m and b from page 116 of Mark Owen's Practical Signal Processing.
|
|
float laplace_problt(float x);
|
|
// look into the actual distribution.
|
|
float problt(float x);
|
|
|
|
private:
|
|
float log_tail_;
|
|
float log_rate_;
|
|
};
|
|
|
|
} //namespace FT8
|
|
|
|
#endif // _ft8stats_h_
|