Commit 553898f6 authored by Manolis Surligas's avatar Manolis Surligas

Improve CW decoding

* Introduce the hysteresis option, in order the CW demodulator to adjust
properly the plateau length based on the WPM and any filtering that can
be used before

* Instead for a frame per word, now the CW decoder waits for 10 long
spaces before it commits a frame. With this way many words are placed on
the same frame telemetry decoding is easier
parent 0d21c594
<?xml version="1.0"?>
<block>
<name>CW to Symbols</name>
<key>satnogs_cw_to_symbol</key>
<import>import satnogs</import>
<make>satnogs.cw_to_symbol($sampling_rate, $threshold, $conf_level, $wpm)</make>
<callback>set_act_threshold($threshold)</callback>
<param>
<name>Sampling Rate</name>
<key>sampling_rate</key>
<value>samp_rate</value>
<type>real</type>
</param>
<name>CW to Symbols</name>
<key>satnogs_cw_to_symbol</key>
<import>import satnogs</import>
<make>satnogs.cw_to_symbol($sampling_rate, $threshold, $conf_level, $wpm, $hysteresis)</make>
<callback>set_act_threshold($threshold)</callback>
<param>
<name>Activation Threshold</name>
<key>threshold</key>
<type>real</type>
</param>
<param>
<name>Confidence Level</name>
<key>conf_level</key>
<value>0.9</value>
<type>real</type>
</param>
<param>
<name>Sampling Rate</name>
<key>sampling_rate</key>
<value>samp_rate</value>
<type>real</type>
</param>
<param>
<name>Words per Minute</name>
<key>wpm</key>
<value>20</value>
<type>int</type>
</param>
<param>
<name>Activation Threshold</name>
<key>threshold</key>
<type>real</type>
</param>
<sink>
<name>act_threshold</name>
<type>message</type>
<optional>1</optional>
</sink>
<sink>
<name>in</name>
<type>float</type>
</sink>
<param>
<name>Confidence Level</name>
<key>conf_level</key>
<value>0.9</value>
<type>real</type>
</param>
<source>
<name>out</name>
<type>message</type>
</source>
<param>
<name>Words per Minute</name>
<key>wpm</key>
<value>20</value>
<type>int</type>
</param>
<param>
<name>Hysteresis</name>
<key>hysteresis</key>
<value>0</value>
<type>int</type>
</param>
<sink>
<name>act_threshold</name>
<type>message</type>
<optional>1</optional>
</sink>
<sink>
<name>in</name>
<type>float</type>
</sink>
<source>
<name>out</name>
<type>message</type>
</source>
</block>
......@@ -24,6 +24,9 @@
#include <satnogs/api.h>
#include <gnuradio/sync_block.h>
#define MIN_WPM 5
#define MAX_WPM 50
namespace gr
{
namespace satnogs
......@@ -65,10 +68,19 @@ namespace gr
* symbols
*
* @param wpm Morse code Words per Minute
*
* @param hysteresis this value represents the hysteresis of a possible
* filter used before the CW to Symbol block. For example if there is
* a moving average filter with x taps, the full power of the signal
* will be available after x samples. The total length of samples with
* maximum power will be 2*x less. Because the block searches for plateaus
* with proper durations, this filtering hysteresis should be known.
* If no such a filter is used, the hysteresis value should be set to zero.
*/
static cw_to_symbol::sptr
make (double sampling_rate, float threshold, float conf_level = 0.9,
size_t wpm = 20);
size_t wpm = 20,
size_t hysteresis = 0);
virtual void
set_act_threshold (float thrld) = 0;
......
......@@ -2,7 +2,7 @@
/*
* gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
*
* Copyright (C) 2016,2017
* Copyright (C) 2016-2018
* Libre Space Foundation <http://librespacefoundation.org/>
*
* This program is free software: you can redistribute it and/or modify
......@@ -22,8 +22,6 @@
#ifndef INCLUDE_SATNOGS_MORSE_H_
#define INCLUDE_SATNOGS_MORSE_H_
#define MIN_WPM 5
#define MAX_WPM 30
/**
* The different Morse symbols
*/
......@@ -32,7 +30,8 @@ typedef enum {
MORSE_DASH, //!< Morse dash (-) symbol
MORSE_INTRA_SPACE, //!< Space between dot and dash symbols
MORSE_S_SPACE, //!< Morse short space between characters
MORSE_L_SPACE //!<Morse long space between words
MORSE_L_SPACE, //!<Morse long space between words
MORSE_END_MSG_SPACE //!< End of message
} morse_symbol_t;
......
This diff is collapsed.
......@@ -45,6 +45,7 @@ namespace gr
size_t d_dot_samples;
size_t d_window_size;
size_t d_window_cnt;
size_t d_idle_cnt;
size_t d_dot_windows_num;
size_t d_dash_windows_num;
size_t d_short_pause_windows_num;
......@@ -84,7 +85,7 @@ namespace gr
public:
cw_to_symbol_impl (double sampling_rate, float threshold,
float conf_level, size_t wpm);
float conf_level, size_t wpm, size_t hysteresis);
~cw_to_symbol_impl ();
// Where all the action really happens
......
......@@ -28,94 +28,99 @@
#include <satnogs/log.h>
namespace gr
{
namespace satnogs
{
morse_decoder::sptr
morse_decoder::make (char unrecognized_char, size_t min_frame_len)
{
return gnuradio::get_initial_sptr (
new morse_decoder_impl (unrecognized_char, min_frame_len));
}
namespace satnogs
{
void
morse_decoder_impl::symbol_msg_handler (pmt::pmt_t msg)
{
bool res = false;
std::string str;
morse_symbol_t s;
s = (morse_symbol_t) pmt::to_long (msg);
morse_decoder::sptr
morse_decoder::make (char unrecognized_char, size_t min_frame_len)
{
return gnuradio::get_initial_sptr (
new morse_decoder_impl (unrecognized_char, min_frame_len));
}
switch (s)
{
case MORSE_DOT:
case MORSE_DASH:
case MORSE_S_SPACE:
res = d_morse_tree.received_symbol (s);
break;
/*
* If a word separator occurs it is a good time to retrieve the decoded
* word
*/
case MORSE_L_SPACE:
/*
* Inject a character separator, for the morse decoder to commit
* the outstanding character
*/
res = d_morse_tree.received_symbol (MORSE_S_SPACE);
/* Just ignore the word separator if no word is yet decoded */
if (d_morse_tree.get_word_len () == 0) {
res = true;
break;
}
str = d_morse_tree.get_word ();
if (str.length () > d_min_frame_len) {
d_morse_tree.reset ();
message_port_pub (pmt::mp ("out"),
pmt::make_blob (str.c_str (), str.length ()));
}
break;
case MORSE_INTRA_SPACE:
/*Ignore it */
break;
default:
LOG_ERROR("Unknown Morse symbol");
return;
}
void
morse_decoder_impl::symbol_msg_handler (pmt::pmt_t msg)
{
bool res = false;
morse_symbol_t s;
s = (morse_symbol_t) pmt::to_long (msg);
switch (s)
{
case MORSE_DOT:
case MORSE_DASH:
case MORSE_S_SPACE:
res = d_morse_tree.received_symbol (s);
break;
/*
* If a word separator occurs it is a good time to retrieve the decoded
* word
*/
case MORSE_L_SPACE:
/*
* If the decoding return false, it means that either an non decode-able
* character situation occurred or the maximum word limit reached
* Inject a character separator, for the morse decoder to commit
* the outstanding character
*/
if (!res) {
if (d_morse_tree.get_max_word_len () == d_morse_tree.get_word_len ()) {
str = d_morse_tree.get_word ();
d_morse_tree.reset ();
message_port_pub (pmt::mp ("out"),
pmt::make_blob (str.c_str (), str.length ()));
}
res = d_morse_tree.received_symbol (MORSE_S_SPACE);
/* Just ignore the word separator if no word is yet decoded */
if (d_morse_tree.get_word_len () == 0) {
res = true;
break;
}
d_str = d_str.append(d_morse_tree.get_word ());
d_str = d_str.append(" ");
d_morse_tree.reset ();
break;
case MORSE_INTRA_SPACE:
/*Ignore it */
break;
case MORSE_END_MSG_SPACE:
if (d_str.length () > d_min_frame_len) {
d_morse_tree.reset ();
message_port_pub (pmt::mp ("out"),
pmt::make_blob (d_str.c_str (), d_str.length ()));
d_str = "";
}
break;
default:
LOG_ERROR("Unknown Morse symbol");
return;
}
/*
* The private constructor
*/
morse_decoder_impl::morse_decoder_impl (char unrecognized_char,
size_t min_frame_len) :
gr::block ("morse_decoder", gr::io_signature::make (0, 0, 0),
gr::io_signature::make (0, 0, 0)),
d_morse_tree (unrecognized_char),
d_min_frame_len (min_frame_len)
{
/* Register the input and output msg handler */
message_port_register_in (pmt::mp ("in"));
message_port_register_out (pmt::mp ("out"));
set_msg_handler (
pmt::mp ("in"),
boost::bind (&morse_decoder_impl::symbol_msg_handler, this, _1));
/*
* If the decoding return false, it means that either an non decode-able
* character situation occurred or the maximum word limit reached
*/
if (!res) {
if (d_morse_tree.get_max_word_len () == d_morse_tree.get_word_len ()) {
d_str = d_morse_tree.get_word ();
d_morse_tree.reset ();
message_port_pub (pmt::mp ("out"),
pmt::make_blob (d_str.c_str (), d_str.length ()));
}
}
}
/*
* The private constructor
*/
morse_decoder_impl::morse_decoder_impl (char unrecognized_char,
size_t min_frame_len) :
gr::block ("morse_decoder", gr::io_signature::make (0, 0, 0),
gr::io_signature::make (0, 0, 0)),
d_morse_tree (unrecognized_char),
d_min_frame_len (min_frame_len),
d_str("")
{
/* Register the input and output msg handler */
message_port_register_in (pmt::mp ("in"));
message_port_register_out (pmt::mp ("out"));
set_msg_handler (
pmt::mp ("in"),
boost::bind (&morse_decoder_impl::symbol_msg_handler, this, _1));
}
} /* namespace satnogs */
} /* namespace satnogs */
} /* namespace gr */
......@@ -24,24 +24,27 @@
#include <satnogs/morse_decoder.h>
#include <satnogs/morse_tree.h>
namespace gr {
namespace satnogs {
namespace gr
{
namespace satnogs
{
class morse_decoder_impl : public morse_decoder
{
private:
morse_tree d_morse_tree;
size_t d_min_frame_len;
class morse_decoder_impl : public morse_decoder
{
void
symbol_msg_handler(pmt::pmt_t msg);
public:
morse_decoder_impl (char unrecognized_char, size_t min_frame_len);
public:
morse_decoder_impl(char unrecognized_char, size_t min_frame_len);
private:
morse_tree d_morse_tree;
size_t d_min_frame_len;
std::string d_str;
};
void
symbol_msg_handler (pmt::pmt_t msg);
};
} // namespace satnogs
} // namespace satnogs
} // namespace gr
#endif /* INCLUDED_SATNOGS_MORSE_DECODER_IMPL_H */
......
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