diff --git a/docs/changelog.md b/docs/changelog.md
index ca4e09724..36aacdba5 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -36,6 +36,9 @@ SPDX-FileCopyrightText: 2011-2021 Carles Fernandez-Prades <carles.fernandez@cttc
   asking them to sign the CLA document).
 - Improved handling of change in GNU Radio 3.9 FFT API.
 - Improved handling of the filesystem library.
+- Added an abstract class `SignalSourceInterface` and a common base class
+  `SignalSourceBase`, which allow to remove a lot of duplicated code in Signal
+  Source blocks, and further abstract file-based interfaces behind them.
 - Do not apply clang-tidy fixes to protobuf-generated headers.
 - Refactored private implementation of flow graph connection and disconnection
   for improved source code readability.
diff --git a/src/algorithms/libs/CMakeLists.txt b/src/algorithms/libs/CMakeLists.txt
index e8bd6f0aa..7eb20fa87 100644
--- a/src/algorithms/libs/CMakeLists.txt
+++ b/src/algorithms/libs/CMakeLists.txt
@@ -31,6 +31,7 @@ set(GNSS_SPLIBS_SOURCES
     item_type_helpers.cc
     pass_through.cc
     short_x2_to_cshort.cc
+    gnss_sdr_string_literals.cc
 )
 
 set(GNSS_SPLIBS_HEADERS
@@ -61,6 +62,7 @@ set(GNSS_SPLIBS_HEADERS
     item_type_helpers.h
     pass_through.h
     short_x2_to_cshort.h
+    gnss_sdr_string_literals.h
 )
 
 if(ENABLE_OPENCL)
diff --git a/src/algorithms/libs/gnss_sdr_string_literals.cc b/src/algorithms/libs/gnss_sdr_string_literals.cc
new file mode 100644
index 000000000..214d487e5
--- /dev/null
+++ b/src/algorithms/libs/gnss_sdr_string_literals.cc
@@ -0,0 +1,37 @@
+/*!
+ * \file gnss_sdr_string_literals.cc
+ * \brief This file implements the ""s operator for std::string in C++11, and
+ * puts it into the std::string_literals namespace. This is already implemented
+ * in C++14, so this is only compiled when using C++11. The .cc file is required
+ * for avoiding the duplication of symbols.
+ *
+ * \author Carles Fernandez-Prades, 2021. cfernandez(at)cttc.es
+ *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#include "gnss_sdr_string_literals.h"
+
+#if __cplusplus == 201103L
+
+namespace std
+{
+namespace string_literals
+{
+std::string operator"" s(const char* str, std::size_t len)
+{
+    return std::string(str, len);
+};
+}  // namespace string_literals
+}  // namespace std
+
+#endif  // __cplusplus == 201103L
diff --git a/src/algorithms/libs/gnss_sdr_string_literals.h b/src/algorithms/libs/gnss_sdr_string_literals.h
new file mode 100644
index 000000000..c932d1ac2
--- /dev/null
+++ b/src/algorithms/libs/gnss_sdr_string_literals.h
@@ -0,0 +1,48 @@
+/*!
+ * \file gnss_sdr_string_literals.h
+ * \brief This file implements the ""s operator for std::string in C++11, and
+ * puts it into the std::string_literals namespace. This is already implemented
+ * in C++14, so this is only compiled when using C++11. The .cc file is required
+ * for avoiding the duplication of symbols.
+ *
+ * \author Carles Fernandez-Prades, 2021. cfernandez(at)cttc.es
+ *
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
+ * This file is part of GNSS-SDR.
+ *
+ * Copyright (C) 2010-2021  (see AUTHORS file for a list of contributors)
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * -----------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_STRING_LITERALS_H
+#define GNSS_SDR_STRING_LITERALS_H
+
+/** \addtogroup Algorithms_Library
+ * \{ */
+/** \addtogroup Algorithm_libs algorithms_libs
+ * \{ */
+
+#if __cplusplus == 201103L
+
+#include <cstddef>
+#include <string>
+
+namespace std
+{
+namespace string_literals
+{
+std::string operator"" s(const char* str, std::size_t len);
+}  // namespace string_literals
+}  // namespace std
+
+#endif  // __cplusplus == 201103L
+
+/** \} */
+/** \} */
+
+#endif  // GNSS_SDR_STRING_LITERALS_H
diff --git a/src/algorithms/signal_source/adapters/CMakeLists.txt b/src/algorithms/signal_source/adapters/CMakeLists.txt
index c0f60592c..14c14a031 100644
--- a/src/algorithms/signal_source/adapters/CMakeLists.txt
+++ b/src/algorithms/signal_source/adapters/CMakeLists.txt
@@ -160,6 +160,7 @@ target_link_libraries(signal_source_adapters
         Gnuradio::blocks
         signal_source_gr_blocks
     PRIVATE
+        algorithms_libs
         gnss_sdr_flags
         core_system_parameters
         Glog::glog
@@ -172,18 +173,6 @@ if(GNURADIO_USES_STD_POINTERS)
     )
 endif()
 
-# This should really be at a higher level and apply universally to the
-# build system
-if(FILESYSTEM_FOUND)
-    target_compile_definitions(signal_source_adapters PUBLIC -DHAS_STD_FILESYSTEM=1)
-    if(find_experimental)
-        target_compile_definitions(signal_source_adapters PUBLIC -DHAS_STD_FILESYSTEM_EXPERIMENTAL=1)
-    endif()
-    target_link_libraries(signal_source_adapters PUBLIC std::filesystem)
-else()
-    target_link_libraries(signal_source_adapters PUBLIC Boost::filesystem Boost::system)
-endif()
-
 if(ENABLE_RAW_UDP AND PCAP_FOUND)
     target_link_libraries(signal_source_adapters
         PRIVATE
diff --git a/src/algorithms/signal_source/adapters/ad9361_fpga_signal_source.cc b/src/algorithms/signal_source/adapters/ad9361_fpga_signal_source.cc
index bfd5f1e21..42843cb45 100644
--- a/src/algorithms/signal_source/adapters/ad9361_fpga_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/ad9361_fpga_signal_source.cc
@@ -25,6 +25,7 @@
 #include "ad9361_manager.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
 #include "uio_fpga.h"
 #include <glog/logging.h>
 #include <iio.h>
diff --git a/src/algorithms/signal_source/adapters/custom_udp_signal_source.cc b/src/algorithms/signal_source/adapters/custom_udp_signal_source.cc
index 4c59f5dc6..6c260438d 100644
--- a/src/algorithms/signal_source/adapters/custom_udp_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/custom_udp_signal_source.cc
@@ -17,6 +17,7 @@
 
 #include "custom_udp_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <iostream>
 
diff --git a/src/algorithms/signal_source/adapters/file_signal_source.cc b/src/algorithms/signal_source/adapters/file_signal_source.cc
index c42e0f505..d1267949e 100644
--- a/src/algorithms/signal_source/adapters/file_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/file_signal_source.cc
@@ -17,6 +17,7 @@
  */
 
 #include "file_signal_source.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 
 using namespace std::string_literals;
diff --git a/src/algorithms/signal_source/adapters/file_source_base.cc b/src/algorithms/signal_source/adapters/file_source_base.cc
index 4d23df313..4e172e76b 100644
--- a/src/algorithms/signal_source/adapters/file_source_base.cc
+++ b/src/algorithms/signal_source/adapters/file_source_base.cc
@@ -18,6 +18,7 @@
 #include "configuration_interface.h"
 #include "gnss_sdr_filesystem.h"
 #include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <cmath>  // ceil, floor
diff --git a/src/algorithms/signal_source/adapters/flexiband_signal_source.cc b/src/algorithms/signal_source/adapters/flexiband_signal_source.cc
index 2794abfea..03065374e 100644
--- a/src/algorithms/signal_source/adapters/flexiband_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/flexiband_signal_source.cc
@@ -18,6 +18,7 @@
 
 #include "flexiband_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <teleorbit/frontend.h>
diff --git a/src/algorithms/signal_source/adapters/fmcomms2_signal_source.cc b/src/algorithms/signal_source/adapters/fmcomms2_signal_source.cc
index e4acab5c4..9a7b9213f 100644
--- a/src/algorithms/signal_source/adapters/fmcomms2_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/fmcomms2_signal_source.cc
@@ -22,6 +22,7 @@
 #include "ad9361_manager.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <algorithm>  // for max
diff --git a/src/algorithms/signal_source/adapters/gn3s_signal_source.cc b/src/algorithms/signal_source/adapters/gn3s_signal_source.cc
index b598ec460..0262b1a0c 100644
--- a/src/algorithms/signal_source/adapters/gn3s_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/gn3s_signal_source.cc
@@ -16,6 +16,7 @@
 
 #include "gn3s_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <gn3s/gn3s_source_cc.h>
diff --git a/src/algorithms/signal_source/adapters/labsat_signal_source.cc b/src/algorithms/signal_source/adapters/labsat_signal_source.cc
index 8e26c6166..e779e3cb9 100644
--- a/src/algorithms/signal_source/adapters/labsat_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/labsat_signal_source.cc
@@ -16,6 +16,7 @@
 
 #include "labsat_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "labsat23_source.h"
 #include <glog/logging.h>
 
diff --git a/src/algorithms/signal_source/adapters/multichannel_file_signal_source.cc b/src/algorithms/signal_source/adapters/multichannel_file_signal_source.cc
index af9008e54..fd7973d90 100644
--- a/src/algorithms/signal_source/adapters/multichannel_file_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/multichannel_file_signal_source.cc
@@ -18,6 +18,7 @@
 #include "multichannel_file_signal_source.h"
 #include "configuration_interface.h"
 #include "gnss_sdr_flags.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <exception>
diff --git a/src/algorithms/signal_source/adapters/nsr_file_signal_source.cc b/src/algorithms/signal_source/adapters/nsr_file_signal_source.cc
index 7223a8bf2..c2463fc54 100644
--- a/src/algorithms/signal_source/adapters/nsr_file_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/nsr_file_signal_source.cc
@@ -17,6 +17,7 @@
  */
 
 #include "nsr_file_signal_source.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 
 using namespace std::string_literals;
diff --git a/src/algorithms/signal_source/adapters/osmosdr_signal_source.cc b/src/algorithms/signal_source/adapters/osmosdr_signal_source.cc
index 1f1208f85..8809aa378 100644
--- a/src/algorithms/signal_source/adapters/osmosdr_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/osmosdr_signal_source.cc
@@ -18,6 +18,7 @@
 #include "osmosdr_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
diff --git a/src/algorithms/signal_source/adapters/plutosdr_signal_source.cc b/src/algorithms/signal_source/adapters/plutosdr_signal_source.cc
index 4db0dd3e5..7007d4b8d 100644
--- a/src/algorithms/signal_source/adapters/plutosdr_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/plutosdr_signal_source.cc
@@ -18,6 +18,7 @@
 #include "plutosdr_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <iostream>
diff --git a/src/algorithms/signal_source/adapters/raw_array_signal_source.cc b/src/algorithms/signal_source/adapters/raw_array_signal_source.cc
index 3da39ad48..b282aad24 100644
--- a/src/algorithms/signal_source/adapters/raw_array_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/raw_array_signal_source.cc
@@ -17,6 +17,7 @@
 #include "raw_array_signal_source.h"
 #include "concurrent_queue.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/file_sink.h>
 #include <pmt/pmt.h>
diff --git a/src/algorithms/signal_source/adapters/rtl_tcp_signal_source.cc b/src/algorithms/signal_source/adapters/rtl_tcp_signal_source.cc
index 4ebe1c34e..2ebcc3445 100644
--- a/src/algorithms/signal_source/adapters/rtl_tcp_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/rtl_tcp_signal_source.cc
@@ -19,6 +19,7 @@
 #include "rtl_tcp_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <cstdint>
diff --git a/src/algorithms/signal_source/adapters/signal_source_base.cc b/src/algorithms/signal_source/adapters/signal_source_base.cc
index 3ca144181..f8291e094 100644
--- a/src/algorithms/signal_source/adapters/signal_source_base.cc
+++ b/src/algorithms/signal_source/adapters/signal_source_base.cc
@@ -20,6 +20,7 @@
 
 #include "signal_source_base.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <utility>  // move
 
 
diff --git a/src/algorithms/signal_source/adapters/spir_file_signal_source.cc b/src/algorithms/signal_source/adapters/spir_file_signal_source.cc
index f7e74ed12..23d74e93b 100644
--- a/src/algorithms/signal_source/adapters/spir_file_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/spir_file_signal_source.cc
@@ -16,6 +16,7 @@
  */
 
 #include "spir_file_signal_source.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 
 
diff --git a/src/algorithms/signal_source/adapters/spir_gss6450_file_signal_source.cc b/src/algorithms/signal_source/adapters/spir_gss6450_file_signal_source.cc
index 344f1dec7..77069bd50 100644
--- a/src/algorithms/signal_source/adapters/spir_gss6450_file_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/spir_gss6450_file_signal_source.cc
@@ -18,6 +18,7 @@
 
 #include "spir_gss6450_file_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <exception>
 #include <fstream>
diff --git a/src/algorithms/signal_source/adapters/two_bit_cpx_file_signal_source.cc b/src/algorithms/signal_source/adapters/two_bit_cpx_file_signal_source.cc
index 40ba1295f..7bf1cb831 100644
--- a/src/algorithms/signal_source/adapters/two_bit_cpx_file_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/two_bit_cpx_file_signal_source.cc
@@ -16,6 +16,7 @@
  */
 
 #include "two_bit_cpx_file_signal_source.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 
 using namespace std::string_literals;
diff --git a/src/algorithms/signal_source/adapters/two_bit_packed_file_signal_source.cc b/src/algorithms/signal_source/adapters/two_bit_packed_file_signal_source.cc
index 3fcb279e2..ae8226dfd 100644
--- a/src/algorithms/signal_source/adapters/two_bit_packed_file_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/two_bit_packed_file_signal_source.cc
@@ -18,6 +18,7 @@
 
 #include "two_bit_packed_file_signal_source.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include <glog/logging.h>
 #include <gnuradio/blocks/char_to_float.h>
 
diff --git a/src/algorithms/signal_source/adapters/uhd_signal_source.cc b/src/algorithms/signal_source/adapters/uhd_signal_source.cc
index 551a46978..16bf5cb83 100644
--- a/src/algorithms/signal_source/adapters/uhd_signal_source.cc
+++ b/src/algorithms/signal_source/adapters/uhd_signal_source.cc
@@ -17,6 +17,7 @@
 #include "uhd_signal_source.h"
 #include "GPS_L1_CA.h"
 #include "configuration_interface.h"
+#include "gnss_sdr_string_literals.h"
 #include "gnss_sdr_valve.h"
 #include <glog/logging.h>
 #include <uhd/exception.hpp>
diff --git a/src/core/interfaces/signal_source_interface.h b/src/core/interfaces/signal_source_interface.h
index 9c8c998e2..df4a7baf4 100644
--- a/src/core/interfaces/signal_source_interface.h
+++ b/src/core/interfaces/signal_source_interface.h
@@ -27,6 +27,7 @@
 #define GNSS_SDR_SIGNAL_SOURCE_INTERFACE_H
 
 #include "gnss_block_interface.h"
+#include <glog/logging.h>
 
 /** \addtogroup Core
  * \{ */
@@ -42,7 +43,6 @@
  * implemented by that class or a parent class.
  */
 
-#include <glog/logging.h>
 class SignalSourceInterface : public GNSSBlockInterface
 {
 public:
diff --git a/src/core/receiver/CMakeLists.txt b/src/core/receiver/CMakeLists.txt
index 9d54be4a3..896ef5aad 100644
--- a/src/core/receiver/CMakeLists.txt
+++ b/src/core/receiver/CMakeLists.txt
@@ -151,6 +151,7 @@ target_link_libraries(core_receiver
     PUBLIC
         core_libs
     PRIVATE
+        algorithms_libs
         core_monitor
         signal_source_adapters
         data_type_adapters
@@ -169,8 +170,6 @@ target_link_libraries(core_receiver
         Armadillo::armadillo
 )
 
-target_include_directories(core_receiver PRIVATE ${CMAKE_SOURCE_DIR}/src/algorithms/libs)
-
 if(ENABLE_ARMA_NO_DEBUG)
     target_compile_definitions(core_receiver
         PRIVATE -DARMA_NO_BOUND_CHECKING=1
diff --git a/src/core/receiver/gnss_block_factory.cc b/src/core/receiver/gnss_block_factory.cc
index 566a1c13d..7bcbde86e 100644
--- a/src/core/receiver/gnss_block_factory.cc
+++ b/src/core/receiver/gnss_block_factory.cc
@@ -68,6 +68,7 @@
 #include "glonass_l2_ca_telemetry_decoder.h"
 #include "gnss_block_interface.h"
 #include "gnss_sdr_make_unique.h"
+#include "gnss_sdr_string_literals.h"
 #include "gps_l1_ca_dll_pll_tracking.h"
 #include "gps_l1_ca_kf_tracking.h"
 #include "gps_l1_ca_pcps_acquisition.h"
@@ -204,8 +205,6 @@ auto findRole(ConfigurationInterface const* configuration, std::string const& ba
         }
     return role;
 };
-
-
 }  // namespace