diff --git a/grc/CMakeLists.txt b/grc/CMakeLists.txt
index ef36631..7980c48 100644
--- a/grc/CMakeLists.txt
+++ b/grc/CMakeLists.txt
@@ -19,5 +19,5 @@
install(FILES
ccsds_ccsds_encoder.xml
ccsds_ccsds_decoder.xml
- DESTINATION share/gnuradio/grc/blocks
+ ccsds_correlator.xml DESTINATION share/gnuradio/grc/blocks
)
diff --git a/grc/ccsds_correlator.xml b/grc/ccsds_correlator.xml
new file mode 100644
index 0000000..f01a8db
--- /dev/null
+++ b/grc/ccsds_correlator.xml
@@ -0,0 +1,40 @@
+
+
+ Correlator
+ ccsds_correlator
+ [CCSDS]
+ import ccsds
+ ccsds.correlator($asm, $asm_mask, $threshold, $frame_len)
+
+ ASM
+ asm
+ 0x1acffc1d
+ int
+
+
+ ASM Mask
+ asm_mask
+ 0xffffffff
+ int
+
+
+ Threshold Mask
+ threshold
+ 0
+ int
+
+
+ Frame Length
+ frame_len
+ 223
+ int
+
+
+ in
+ byte
+
+
+ out
+ message
+
+
diff --git a/include/ccsds/CMakeLists.txt b/include/ccsds/CMakeLists.txt
index 6b2ee19..09296de 100644
--- a/include/ccsds/CMakeLists.txt
+++ b/include/ccsds/CMakeLists.txt
@@ -24,5 +24,5 @@ install(FILES
api.h
ccsds_encoder.h
ccsds_decoder.h
- DESTINATION include/ccsds
+ correlator.h DESTINATION include/ccsds
)
diff --git a/include/ccsds/correlator.h b/include/ccsds/correlator.h
new file mode 100644
index 0000000..20444a0
--- /dev/null
+++ b/include/ccsds/correlator.h
@@ -0,0 +1,60 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 André Løfaldli.
+ *
+ * This 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; either version 3, or (at your option)
+ * any later version.
+ *
+ * This software 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#ifndef INCLUDED_CCSDS_CORRELATOR_H
+#define INCLUDED_CCSDS_CORRELATOR_H
+
+#include
+#include
+
+namespace gr {
+ namespace ccsds {
+
+ /*!
+ * \brief CCSDS correlator
+ * \ingroup ccsds
+ *
+ * looks for the attached sync marker and produces pdus containing frames
+ */
+ class CCSDS_API correlator : virtual public gr::sync_block
+ {
+ public:
+ typedef boost::shared_ptr sptr;
+
+ /*!
+ * \brief make the correlator.
+ *
+ * \param asm attached sync marker
+ * \param asm_mask mask for attached sync marker
+ * \param threshold maximum number of allowed errors in asm
+ * \param frame_len length of the transfer frame
+ */
+ static sptr make(const uint64_t asm_=0x1acffc1d,
+ const uint64_t asm_mask=0xffffffff,
+ const uint8_t threshold=2,
+ const size_t frame_len=223);
+ };
+
+ } // namespace ccsds
+} // namespace gr
+
+#endif /* INCLUDED_CCSDS_CORRELATOR_H */
+
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 6319c8a..4b08d0d 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -33,7 +33,7 @@ list(APPEND ccsds_sources
reed_solomon.cc
ccsds_encoder_impl.cc
ccsds_decoder_impl.cc
- )
+ correlator_impl.cc )
set(ccsds_sources "${ccsds_sources}" PARENT_SCOPE)
if(NOT ccsds_sources)
diff --git a/lib/correlator_impl.cc b/lib/correlator_impl.cc
new file mode 100644
index 0000000..85d8fd4
--- /dev/null
+++ b/lib/correlator_impl.cc
@@ -0,0 +1,148 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 André Løfaldli.
+ *
+ * This 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; either version 3, or (at your option)
+ * any later version.
+ *
+ * This software 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include
+#include
+#include "correlator_impl.h"
+
+#if 0
+#define debug_print printf
+#else
+#define debug_print
+#endif
+
+namespace gr {
+ namespace ccsds {
+
+ correlator::sptr
+ correlator::make(const uint64_t asm_, const uint64_t asm_mask,
+ const uint8_t threshold, const size_t frame_len)
+ {
+ return gnuradio::get_initial_sptr
+ (new correlator_impl(asm_, asm_mask, threshold, frame_len));
+ }
+
+ correlator_impl::correlator_impl(const uint64_t asm_, const uint64_t asm_mask,
+ const uint8_t threshold, const size_t frame_len)
+ : gr::sync_block("correlator",
+ gr::io_signature::make(1, 1, sizeof(uint8_t)),
+ gr::io_signature::make(0, 0, 0)),
+ d_asm(asm_), d_asm_mask(asm_mask),
+ d_threshold(threshold), d_frame_len(frame_len),
+ d_frame_count(0), d_ambiguity(NONE)
+ {
+ message_port_register_out(pmt::mp("out"));
+ d_frame_buffer = (uint8_t *)malloc(frame_len * sizeof(uint8_t));
+ enter_state(SEARCH);
+ }
+
+ correlator_impl::~correlator_impl() {
+ free(d_frame_buffer);
+ }
+
+ int
+ correlator_impl::work(int noutput_items,
+ gr_vector_const_void_star &input_items,
+ gr_vector_void_star &output_items)
+ {
+ const uint8_t *in = (const uint8_t *) input_items[0];
+
+ uint64_t count = 0;
+ while (count < noutput_items) {
+ switch (d_state) {
+ case SEARCH:
+ d_asm_buf = (d_asm_buf << 1) | (in[count++] & 0x01);
+ if (check_asm(d_asm_buf)) {
+ d_ambiguity = NONE;
+ enter_state(LOCK);
+ } else if (check_asm(d_asm_buf ^ 0xffffffffffffffff)) {
+ d_ambiguity = INVERTED;
+ enter_state(LOCK);
+ }
+ break;
+ case LOCK:
+ d_byte_buf = (d_byte_buf << 1) | (in[count++] & 0x01);
+ d_bit_ctr++;
+ if (d_bit_ctr == 8) {
+ if (d_ambiguity == NONE) {
+ d_frame_buffer[d_frame_buffer_len] = d_byte_buf;
+ } else if (d_ambiguity == INVERTED) {
+ d_frame_buffer[d_frame_buffer_len] = d_byte_buf ^ 0xff;
+ }
+ d_frame_buffer_len++;
+ d_bit_ctr = 0;
+ }
+ if (d_frame_buffer_len == d_frame_len) {
+ publish_msg();
+ d_frame_count++;
+ enter_state(SEARCH);
+ }
+ break;
+ }
+ }
+ return noutput_items;
+ }
+
+ bool correlator_impl::check_asm(const uint64_t asm_buf) {
+ debug_print("check_asm\n");
+
+ uint64_t nerrors = 0;
+ const uint64_t syndrome = (asm_buf ^ d_asm) & d_asm_mask;
+ volk_64u_popcnt(&nerrors, syndrome);
+ return nerrors <= (uint64_t)d_threshold;
+ }
+
+ void correlator_impl::enter_state(const state_t state) {
+ debug_print("enter_state ");
+
+ switch (state) {
+ case SEARCH:
+ debug_print("SEARCH\n");
+
+ d_asm_buf = 0;
+ break;
+ case LOCK:
+ debug_print("LOCK\n");
+
+ d_byte_buf = 0;
+ d_bit_ctr = 0;
+ d_frame_buffer_len = 0;
+ break;
+ }
+ d_state = state;
+ }
+
+ void correlator_impl::publish_msg() {
+ debug_print("publish_msg #%lu\n", d_frame_count);
+
+ pmt::pmt_t meta = pmt::make_dict();
+ meta = dict_add(meta, pmt::intern("frame_count"),
+ pmt::from_uint64(d_frame_count));
+ const pmt::pmt_t data = pmt::init_u8vector(d_frame_len, d_frame_buffer);
+ message_port_pub(pmt::mp("out"), pmt::cons(meta, data));
+ }
+
+ } /* namespace ccsds */
+} /* namespace gr */
+
diff --git a/lib/correlator_impl.h b/lib/correlator_impl.h
new file mode 100644
index 0000000..4de46bc
--- /dev/null
+++ b/lib/correlator_impl.h
@@ -0,0 +1,65 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 André Løfaldli.
+ *
+ * This 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; either version 3, or (at your option)
+ * any later version.
+ *
+ * This software 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_CCSDS_CORRELATOR_IMPL_H
+#define INCLUDED_CCSDS_CORRELATOR_IMPL_H
+
+#include
+#include
+
+namespace gr {
+ namespace ccsds {
+
+ enum state_t { SEARCH, LOCK };
+ enum ambiguity_t { NONE, INVERTED };
+
+ class correlator_impl : public correlator {
+ private:
+ const uint64_t d_asm, d_asm_mask;
+ const uint8_t d_threshold;
+ const size_t d_frame_len;
+
+ uint64_t d_asm_buf;
+ uint8_t *d_frame_buffer;
+ size_t d_frame_buffer_len;
+ uint8_t d_bit_ctr, d_byte_buf;
+
+ state_t d_state;
+ ambiguity_t d_ambiguity;
+ uint64_t d_frame_count;
+
+ public:
+ correlator_impl(const uint64_t asm_, const uint64_t asm_mask,
+ const uint8_t threshold, const size_t frame_len);
+ ~correlator_impl();
+ int work(int noutput_items,
+ gr_vector_const_void_star &input_items,
+ gr_vector_void_star &output_items);
+
+ bool check_asm(const uint64_t asm_buf);
+ void enter_state(const state_t state);
+ void publish_msg();
+ };
+
+ } // namespace ccsds
+} // namespace gr
+
+#endif /* INCLUDED_CCSDS_CORRELATOR_IMPL_H */
+
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index 7b4fe6c..b85a766 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -43,3 +43,4 @@ set(GR_TEST_TARGET_DEPS gnuradio-ccsds)
set(GR_TEST_PYTHON_DIRS ${CMAKE_BINARY_DIR}/swig)
GR_ADD_TEST(qa_ccsds_encoder ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_ccsds_encoder.py)
GR_ADD_TEST(qa_ccsds_decoder ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_ccsds_decoder.py)
+GR_ADD_TEST(qa_correlator ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_correlator.py)
diff --git a/python/qa_correlator.py b/python/qa_correlator.py
new file mode 100755
index 0000000..932b24d
--- /dev/null
+++ b/python/qa_correlator.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2018 André Løfaldli.
+#
+# This 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; either version 3, or (at your option)
+# any later version.
+#
+# This software 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 for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this software; see the file COPYING. If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+import time
+import random
+from gnuradio import gr, gr_unittest
+from gnuradio import blocks, digital
+import pmt
+import ccsds_swig as ccsds
+
+class qa_correlator (gr_unittest.TestCase):
+
+ def setUp (self):
+ self.tb = gr.top_block ()
+
+ def tearDown (self):
+ self.tb = None
+
+ def test_001_t (self):
+ asm = (0x1a, 0xcf, 0xfc, 0x1d)
+ frame_len = 223
+ random_data = tuple(random.randint(0, 255) for _ in range(frame_len))
+
+ data_in = asm + random_data
+
+ src = blocks.vector_source_b(data_in, repeat=True)
+ unpack = blocks.unpack_k_bits_bb(8)
+ corr = ccsds.correlator(0x1acffc1d, 0xffffffff, 0, frame_len)
+ dbg = blocks.message_debug()
+ self.tb.connect(src, unpack, corr)
+ self.tb.msg_connect((corr, 'out'), (dbg, 'store'))
+ self.tb.start()
+
+ while dbg.num_messages() < 1:
+ time.sleep(0.1)
+
+ self.tb.stop()
+ self.tb.wait()
+
+ msg = dbg.get_message(0)
+ data_out = tuple(pmt.to_python(pmt.cdr(msg)))
+
+ assert frame_len == len(data_out)
+ assert random_data == data_out
+
+ def test_002_inverted_bits (self):
+ asm = (0x1a, 0xcf, 0xfc, 0x1d)
+ frame_len = 223
+ random_data = tuple(random.randint(0, 255) for _ in range(frame_len))
+
+ data_in = asm + random_data
+
+ src = blocks.vector_source_b(data_in, repeat=True)
+ unpack = blocks.unpack_k_bits_bb(8)
+ mapper = digital.map_bb((1,0))
+ corr = ccsds.correlator(0x1acffc1d, 0xffffffff, 0, frame_len)
+ dbg = blocks.message_debug()
+ self.tb.connect(src, unpack, mapper, corr)
+ self.tb.msg_connect((corr, 'out'), (dbg, 'store'))
+ self.tb.start()
+
+ while dbg.num_messages() < 1:
+ time.sleep(0.1)
+
+ self.tb.stop()
+ self.tb.wait()
+
+ msg = dbg.get_message(0)
+ data_out = tuple(pmt.to_python(pmt.cdr(msg)))
+
+ assert frame_len == len(data_out)
+ assert random_data == data_out
+
+
+if __name__ == '__main__':
+ gr_unittest.run(qa_correlator, "qa_correlator.xml")
diff --git a/swig/ccsds_swig.i b/swig/ccsds_swig.i
index e2f1903..51fef57 100644
--- a/swig/ccsds_swig.i
+++ b/swig/ccsds_swig.i
@@ -10,6 +10,7 @@
%{
#include "ccsds/ccsds_encoder.h"
#include "ccsds/ccsds_decoder.h"
+#include "ccsds/correlator.h"
%}
@@ -17,3 +18,5 @@
GR_SWIG_BLOCK_MAGIC2(ccsds, ccsds_encoder);
%include "ccsds/ccsds_decoder.h"
GR_SWIG_BLOCK_MAGIC2(ccsds, ccsds_decoder);
+%include "ccsds/correlator.h"
+GR_SWIG_BLOCK_MAGIC2(ccsds, correlator);