Moved control channels decoder to libosmocore implementation
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5832d42..11d589d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -107,6 +107,7 @@
find_package(CppUnit)
find_package(Doxygen)
find_package(Libosmocore)
+find_package(Libosmocoding)
if(NOT GNURADIO_RUNTIME_FOUND)
message(FATAL_ERROR "GnuRadio Runtime required to compile gr-gsm")
@@ -120,6 +121,9 @@
if(NOT LIBOSMOCORE_FOUND)
message(FATAL_ERROR "Libosmocore required to compile gr-gsm")
endif()
+if(NOT LIBOSMOCODING_FOUND)
+ message(FATAL_ERROR "Libosmocoding required to compile gr-gsm")
+endif()
########################################################################
# Setup doxygen option
diff --git a/cmake/Modules/FindLibosmocoding.cmake b/cmake/Modules/FindLibosmocoding.cmake
new file mode 100644
index 0000000..c3e4cbb
--- /dev/null
+++ b/cmake/Modules/FindLibosmocoding.cmake
@@ -0,0 +1,32 @@
+find_package(PkgConfig)
+pkg_check_modules(PC_libosmocoding libosmocoding)
+set(LIBOSMOCODING_DEFINITIONS ${PC_LIBOSMOCODING_CFLAGS_OTHER})
+
+find_path(
+ LIBOSMOCODING_INCLUDE_DIR
+ NAMES osmocom/coding/gsm0503_coding.h
+ HINTS ${PC_libosmocoding_INCLUDEDIR}
+ ${PC_libosmocoding_INCLUDE_DIRS}
+ ${CMAKE_INSTALL_PREFIX}/include
+ PATHS /usr/local/include
+ /usr/include
+)
+
+find_library(
+ LIBOSMOCODING_LIBRARY
+ NAMES libosmocoding osmocoding
+ HINTS ${PC_libosmocoding_LIBDIR}
+ ${PC_libosmocoding_LIBRARY_DIRS}
+ ${CMAKE_INSTALL_PREFIX}/lib/
+ ${CMAKE_INSTALL_PREFIX}/lib64/
+ PATHS /usr/local/lib
+ /usr/lib
+)
+
+
+set(LIBOSMOCODING_LIBRARIES ${LIBOSMOCODING_LIBRARY})
+set(LIBOSMOCODING_INCLUDE_DIRS ${LIBOSMOCODING_INCLUDE_DIR})
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(libosmocoding DEFAULT_MSG LIBOSMOCODING_LIBRARY LIBOSMOCODING_INCLUDE_DIR)
+mark_as_advanced(LIBOSMOCODING_INCLUDE_DIR LIBOSMOCODING_LIBRARY )
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 660bbfd..03903f8 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -71,7 +71,7 @@
add_library(grgsm SHARED ${grgsm_sources})
-target_link_libraries(grgsm ${Boost_LIBRARIES} ${GNURADIO_ALL_LIBRARIES} ${VOLK_LIBRARIES} ${LIBOSMOCORE_LIBRARIES}
+target_link_libraries(grgsm ${Boost_LIBRARIES} ${GNURADIO_ALL_LIBRARIES} ${VOLK_LIBRARIES} ${LIBOSMOCORE_LIBRARIES} ${LIBOSMOCODING_LIBRARIES}
# libraries required by plotting.h - have troubles to be installed by pybombs
# boost_iostreams
# boost_system
diff --git a/lib/decoding/control_channels_decoder_impl.cc b/lib/decoding/control_channels_decoder_impl.cc
index 532e255..ddea256 100644
--- a/lib/decoding/control_channels_decoder_impl.cc
+++ b/lib/decoding/control_channels_decoder_impl.cc
@@ -33,6 +33,25 @@
namespace gr {
namespace gsm {
+ static int ubits2sbits(ubit_t *ubits, sbit_t *sbits, int count)
+ {
+ int i;
+
+ for (i = 0; i < count; i++) {
+ if (*ubits == 0x23) {
+ ubits++;
+ sbits++;
+ continue;
+ }
+ if ((*ubits++) & 1)
+ *sbits++ = -127;
+ else
+ *sbits++ = 127;
+ }
+
+ return count;
+ }
+
control_channels_decoder::sptr
control_channels_decoder::make()
{
@@ -49,18 +68,6 @@
gr::io_signature::make(0, 0, 0)),
d_collected_bursts_num(0)
{
- //initialize de/interleaver
- int j, k, B;
- for (k = 0; k < CONV_SIZE; k++)
- {
- B = k % 4;
- j = 2 * ((49 * k) % 57) + ((k % 8) / 4);
- interleave_trans[k] = B * 114 + j; //114=57 + 57
- }
-
- //initialize decoder
- FC_init(&fc_ctx, 40, 184);
-
//setup input/output ports
message_port_register_in(pmt::mp("bursts"));
set_msg_handler(pmt::mp("bursts"), boost::bind(&control_channels_decoder_impl::decode, this, _1));
@@ -73,7 +80,11 @@
void control_channels_decoder_impl::decode(pmt::pmt_t msg)
{
- unsigned char iBLOCK[BLOCKS*iBLOCK_SIZE], hl, hn, conv_data[CONV_SIZE], decoded_data[PARITY_OUTPUT_SIZE];
+ ubit_t bursts_u[116 * 4];
+ sbit_t bursts_s[116 * 4];
+ uint8_t result[23];
+ int n_errors, n_bits_total;
+
d_bursts[d_collected_bursts_num] = msg;
d_collected_bursts_num++;
//get convecutive bursts
@@ -86,60 +97,22 @@
{
pmt::pmt_t header_plus_burst = pmt::cdr(d_bursts[ii]);
int8_t * burst_bits = (int8_t *)(pmt::blob_data(header_plus_burst))+sizeof(gsmtap_hdr);
-
- for(int jj = 0; jj < 57; jj++)
- {
- iBLOCK[ii*iBLOCK_SIZE+jj] = burst_bits[jj + 3];
- iBLOCK[ii*iBLOCK_SIZE+jj+57] = burst_bits[jj + 88]; //88 = 3+57+1+26+1
- }
+
+ memcpy(&bursts_u[ii*116], &burst_bits[3],58);
+ memcpy(&bursts_u[ii*116+58], &burst_bits[3+57+1+26],58);
}
- //deinterleave
- for (int k = 0; k < CONV_SIZE; k++)
- {
- conv_data[k] = iBLOCK[interleave_trans[k]];
- }
- //convolutional code decode
- int errors = conv_decode(decoded_data, conv_data);
- //std::cout << "Errors:" << errors << " " << parity_check(decoded_data) << std::endl;
- // check parity
- // If parity check error detected try to fix it.
+ //convert to soft bits
+ ubits2sbits(bursts_u, bursts_s, 116 * 4);
+ //decode
+ gsm0503_xcch_decode(result, bursts_s, &n_errors, &n_bits_total);
- if (parity_check(decoded_data))
- {
- FC_init(&fc_ctx, 40, 184);
- unsigned char crc_result[PARITY_OUTPUT_SIZE];
- if (FC_check_crc(&fc_ctx, decoded_data, crc_result) == 0)
- {
- //("error: sacch: parity error (errors=%d fn=%d)\n", errors, ctx->fn);
- //std::cout << "Uncorrectable errors!" << std::endl;
- errors = -1;
- return;
- } else {
- //DEBUGF("Successfully corrected parity bits! (errors=%d fn=%d)\n", errors, ctx->fn);
- //std::cout << "Corrected some errors" << std::endl;
- memcpy(decoded_data, crc_result, PARITY_OUTPUT_SIZE);
- errors = 0;
- }
- } else {
- //std::cout << "Everything correct" << std::endl;
- }
- //compress bits
- unsigned char outmsg[28];
- unsigned char sbuf_len=224;
- int i, j, c, pos=0;
- for(i = 0; i < sbuf_len; i += 8) {
- for(j = 0, c = 0; (j < 8) && (i + j < sbuf_len); j++){
- c |= (!!decoded_data[i + j]) << j;
- }
- outmsg[pos++] = c & 0xff;
- }
-
- //send message with header of the first burst
+ //send to the output
pmt::pmt_t first_header_plus_burst = pmt::cdr(d_bursts[0]);
gsmtap_hdr * header = (gsmtap_hdr *)pmt::blob_data(first_header_plus_burst);
int8_t header_plus_data[sizeof(gsmtap_hdr)+DATA_BYTES];
memcpy(header_plus_data, header, sizeof(gsmtap_hdr));
- memcpy(header_plus_data+sizeof(gsmtap_hdr), outmsg, DATA_BYTES);
+
+ memcpy(header_plus_data+sizeof(gsmtap_hdr), result, DATA_BYTES);
((gsmtap_hdr*)header_plus_data)->type = GSMTAP_TYPE_UM;
pmt::pmt_t msg_binary_blob = pmt::make_blob(header_plus_data,DATA_BYTES+sizeof(gsmtap_hdr));
diff --git a/lib/decoding/control_channels_decoder_impl.h b/lib/decoding/control_channels_decoder_impl.h
index 2fa3dce..542335b 100644
--- a/lib/decoding/control_channels_decoder_impl.h
+++ b/lib/decoding/control_channels_decoder_impl.h
@@ -26,6 +26,10 @@
#include <grgsm/decoding/control_channels_decoder.h>
#include "fire_crc.h"
#include "cch.h"
+extern "C" {
+ #include <osmocom/coding/gsm0503_coding.h>
+ #include <osmocom/core/utils.h>
+}
namespace gr {
namespace gsm {
@@ -35,9 +39,8 @@
private:
unsigned int d_collected_bursts_num;
pmt::pmt_t d_bursts[4];
- unsigned short interleave_trans[CONV_SIZE];
- FC_CTX fc_ctx;
- void decode(pmt::pmt_t msg);
+
+ void decode(pmt::pmt_t msg);
public:
control_channels_decoder_impl();
~control_channels_decoder_impl();