diff --git a/Transceiver52M/Channelizer.cpp b/Transceiver52M/Channelizer.cpp
index 1e4d7d4..341cd0a 100644
--- a/Transceiver52M/Channelizer.cpp
+++ b/Transceiver52M/Channelizer.cpp
@@ -4,6 +4,8 @@
  * Copyright (C) 2012-2014 Tom Tsou <tom@tsou.cc>
  * Copyright (C) 2015 Ettus Research LLC
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/ChannelizerBase.cpp b/Transceiver52M/ChannelizerBase.cpp
index 96f76a9..f3f07c1 100644
--- a/Transceiver52M/ChannelizerBase.cpp
+++ b/Transceiver52M/ChannelizerBase.cpp
@@ -4,6 +4,8 @@
  * Copyright (C) 2012-2014 Tom Tsou <tom@tsou.cc>
  * Copyright (C) 2015 Ettus Research LLC
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/Resampler.cpp b/Transceiver52M/Resampler.cpp
index f545db8..7ba0219 100644
--- a/Transceiver52M/Resampler.cpp
+++ b/Transceiver52M/Resampler.cpp
@@ -2,6 +2,8 @@
  * Rational Sample Rate Conversion
  * Copyright (C) 2012, 2013  Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/Resampler.h b/Transceiver52M/Resampler.h
index bee2436..139b857 100644
--- a/Transceiver52M/Resampler.h
+++ b/Transceiver52M/Resampler.h
@@ -2,6 +2,8 @@
  * Rational Sample Rate Conversion
  * Copyright (C) 2012, 2013  Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/Synthesis.cpp b/Transceiver52M/Synthesis.cpp
index a117390..24da8e6 100644
--- a/Transceiver52M/Synthesis.cpp
+++ b/Transceiver52M/Synthesis.cpp
@@ -4,6 +4,8 @@
  * Copyright (C) 2012-2014 Tom Tsou <tom@tsou.cc>
  * Copyright (C) 2015 Ettus Research LLC
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index 17e0476..af6b0dd 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -1,6 +1,8 @@
 /*
 * Copyright 2008, 2009, 2010 Free Software Foundation, Inc.
 *
+* SPDX-License-Identifier: GPL-3.0+
+*
 * This software is distributed under the terms of the GNU Public License.
 * See the COPYING file in the main directory for details.
 *
diff --git a/Transceiver52M/Transceiver.h b/Transceiver52M/Transceiver.h
index aa2a716..8b5a9b1 100644
--- a/Transceiver52M/Transceiver.h
+++ b/Transceiver52M/Transceiver.h
@@ -1,6 +1,8 @@
 /*
 * Copyright 2008 Free Software Foundation, Inc.
 *
+* SPDX-License-Identifier: GPL-3.0+
+*
 * This software is distributed under the terms of the GNU Public License.
 * See the COPYING file in the main directory for details.
 *
diff --git a/Transceiver52M/arch/arm/convert.c b/Transceiver52M/arch/arm/convert.c
index c94a3d7..ace1b6f 100644
--- a/Transceiver52M/arch/arm/convert.c
+++ b/Transceiver52M/arch/arm/convert.c
@@ -2,6 +2,8 @@
  * NEON type conversions
  * Copyright (C) 2012, 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/arm/convert_neon.S b/Transceiver52M/arch/arm/convert_neon.S
index 842ed9f..a1fbd40 100644
--- a/Transceiver52M/arch/arm/convert_neon.S
+++ b/Transceiver52M/arch/arm/convert_neon.S
@@ -2,6 +2,8 @@
  * NEON type conversions
  * Copyright (C) 2012, 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/arm/convolve.c b/Transceiver52M/arch/arm/convolve.c
index 5b5bce5..63b1655 100644
--- a/Transceiver52M/arch/arm/convolve.c
+++ b/Transceiver52M/arch/arm/convolve.c
@@ -2,6 +2,8 @@
  * NEON Convolution
  * Copyright (C) 2012, 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/arm/convolve_neon.S b/Transceiver52M/arch/arm/convolve_neon.S
index 8a023ff..a3e1ba5 100644
--- a/Transceiver52M/arch/arm/convolve_neon.S
+++ b/Transceiver52M/arch/arm/convolve_neon.S
@@ -2,6 +2,8 @@
  * NEON Convolution
  * Copyright (C) 2012, 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/arm/mult.c b/Transceiver52M/arch/arm/mult.c
index 245be50..9851626 100644
--- a/Transceiver52M/arch/arm/mult.c
+++ b/Transceiver52M/arch/arm/mult.c
@@ -2,6 +2,8 @@
  * NEON scaling
  * Copyright (C) 2012,2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/arm/mult_neon.S b/Transceiver52M/arch/arm/mult_neon.S
index 113e227..6318c50 100644
--- a/Transceiver52M/arch/arm/mult_neon.S
+++ b/Transceiver52M/arch/arm/mult_neon.S
@@ -2,6 +2,8 @@
  * NEON complex multiplication
  * Copyright (C) 2012,2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/arm/scale.c b/Transceiver52M/arch/arm/scale.c
index 2de13ff..a3214f7 100644
--- a/Transceiver52M/arch/arm/scale.c
+++ b/Transceiver52M/arch/arm/scale.c
@@ -2,6 +2,8 @@
  * NEON scaling
  * Copyright (C) 2012,2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/arm/scale_neon.S b/Transceiver52M/arch/arm/scale_neon.S
index a66fbe5..f10de1e 100644
--- a/Transceiver52M/arch/arm/scale_neon.S
+++ b/Transceiver52M/arch/arm/scale_neon.S
@@ -2,6 +2,8 @@
  * ARM NEON Scaling
  * Copyright (C) 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/common/convert_base.c b/Transceiver52M/arch/common/convert_base.c
index 8d29310..9876e83 100644
--- a/Transceiver52M/arch/common/convert_base.c
+++ b/Transceiver52M/arch/common/convert_base.c
@@ -2,6 +2,8 @@
  * Conversion
  * Copyright (C) 2012, 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/common/convolve_base.c b/Transceiver52M/arch/common/convolve_base.c
index 9bb8d3d..bfda783 100644
--- a/Transceiver52M/arch/common/convolve_base.c
+++ b/Transceiver52M/arch/common/convolve_base.c
@@ -2,6 +2,8 @@
  * Convolution
  * Copyright (C) 2012, 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/arch/common/fft.c b/Transceiver52M/arch/common/fft.c
index ed79d13..ad096b1 100644
--- a/Transceiver52M/arch/common/fft.c
+++ b/Transceiver52M/arch/common/fft.c
@@ -3,6 +3,8 @@
  *
  * Copyright (C) 2012 Tom Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/device/common/smpl_buf.cpp b/Transceiver52M/device/common/smpl_buf.cpp
index c21f306..33161bc 100644
--- a/Transceiver52M/device/common/smpl_buf.cpp
+++ b/Transceiver52M/device/common/smpl_buf.cpp
@@ -7,6 +7,8 @@
  *
  * Author: Tom Tsou <tom.tsou@ettus.com>
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/device/common/smpl_buf.h b/Transceiver52M/device/common/smpl_buf.h
index 24d3ce9..383c814 100644
--- a/Transceiver52M/device/common/smpl_buf.h
+++ b/Transceiver52M/device/common/smpl_buf.h
@@ -7,6 +7,8 @@
  *
  * Author: Tom Tsou <tom.tsou@ettus.com>
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/device/lms/LMSDevice.cpp b/Transceiver52M/device/lms/LMSDevice.cpp
index 0253d4c..0eaf0a3 100644
--- a/Transceiver52M/device/lms/LMSDevice.cpp
+++ b/Transceiver52M/device/lms/LMSDevice.cpp
@@ -1,6 +1,8 @@
 /*
 * Copyright 2018 sysmocom - s.f.m.c. GmbH
 *
+* SPDX-License-Identifier: AGPL-3.0+
+*
 	This program is free software: you can redistribute it and/or modify
 	it under the terms of the GNU Affero General Public License as published by
 	the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/device/lms/LMSDevice.h b/Transceiver52M/device/lms/LMSDevice.h
index 9e0944d..906fbee 100644
--- a/Transceiver52M/device/lms/LMSDevice.h
+++ b/Transceiver52M/device/lms/LMSDevice.h
@@ -1,7 +1,10 @@
 /*
 * Copyright 2018 sysmocom - s.f.m.c. GmbH
 *
-* This software is distributed under multiple licenses; see the COPYING file in the main directory for licensing information for this specific distribuion.
+* SPDX-License-Identifier: AGPL-3.0+
+*
+* This software is distributed under multiple licenses; see the COPYING file in
+* the main directory for licensing information for this specific distribuion.
 *
 * This use of this software may be subject to additional restrictions.
 * See the LEGAL file in the main directory for details.
diff --git a/Transceiver52M/device/uhd/UHDDevice.cpp b/Transceiver52M/device/uhd/UHDDevice.cpp
index 4e6f49d..8bb94d6 100644
--- a/Transceiver52M/device/uhd/UHDDevice.cpp
+++ b/Transceiver52M/device/uhd/UHDDevice.cpp
@@ -6,6 +6,8 @@
  *
  * Author: Tom Tsou <tom.tsou@ettus.com>
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/device/uhd/UHDDevice.h b/Transceiver52M/device/uhd/UHDDevice.h
index 0b57ba4..d5a6348 100644
--- a/Transceiver52M/device/uhd/UHDDevice.h
+++ b/Transceiver52M/device/uhd/UHDDevice.h
@@ -7,6 +7,8 @@
  *
  * Author: Tom Tsou <tom.tsou@ettus.com>
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/device/usrp1/USRPDevice.cpp b/Transceiver52M/device/usrp1/USRPDevice.cpp
index b1d6c56..af0b3de 100644
--- a/Transceiver52M/device/usrp1/USRPDevice.cpp
+++ b/Transceiver52M/device/usrp1/USRPDevice.cpp
@@ -1,6 +1,8 @@
 /*
 * Copyright 2008, 2009 Free Software Foundation, Inc.
 *
+* SPDX-License-Identifier: AGPL-3.0+
+*
 * This software is distributed under the terms of the GNU Affero Public License.
 * See the COPYING file in the main directory for details.
 *
diff --git a/Transceiver52M/device/usrp1/USRPDevice.h b/Transceiver52M/device/usrp1/USRPDevice.h
index c02e58c..9a2426c 100644
--- a/Transceiver52M/device/usrp1/USRPDevice.h
+++ b/Transceiver52M/device/usrp1/USRPDevice.h
@@ -1,7 +1,10 @@
 /*
 * Copyright 2008 Free Software Foundation, Inc.
 *
-* This software is distributed under multiple licenses; see the COPYING file in the main directory for licensing information for this specific distribuion.
+* SPDX-License-Identifier: AGPL-3.0+
+*
+* This software is distributed under multiple licenses; see the COPYING file in
+* the main directory for licensing information for this specific distribuion.
 *
 * This use of this software may be subject to additional restrictions.
 * See the LEGAL file in the main directory for details.
diff --git a/Transceiver52M/osmo-trx.cpp b/Transceiver52M/osmo-trx.cpp
index 8a3f1e3..cd659a7 100644
--- a/Transceiver52M/osmo-trx.cpp
+++ b/Transceiver52M/osmo-trx.cpp
@@ -1,6 +1,8 @@
 /*
  * Copyright (C) 2013 Thomas Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: LGPL-2.1+
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
diff --git a/Transceiver52M/radioBuffer.cpp b/Transceiver52M/radioBuffer.cpp
index 57de364..62f6553 100644
--- a/Transceiver52M/radioBuffer.cpp
+++ b/Transceiver52M/radioBuffer.cpp
@@ -5,6 +5,8 @@
  *
  * Author: Tom Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/radioClock.cpp b/Transceiver52M/radioClock.cpp
index 505bb01..2befd0d 100644
--- a/Transceiver52M/radioClock.cpp
+++ b/Transceiver52M/radioClock.cpp
@@ -4,6 +4,8 @@
  *
  * Copyright 2011 Free Software Foundation, Inc.
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/radioClock.h b/Transceiver52M/radioClock.h
index 9c35c44..472f43d 100644
--- a/Transceiver52M/radioClock.h
+++ b/Transceiver52M/radioClock.h
@@ -4,6 +4,8 @@
  *
  * Copyright 2011 Free Software Foundation, Inc.
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/radioInterface.cpp b/Transceiver52M/radioInterface.cpp
index 04b98da..e32848e 100644
--- a/Transceiver52M/radioInterface.cpp
+++ b/Transceiver52M/radioInterface.cpp
@@ -4,6 +4,8 @@
  * Copyright (C) 2008-2014 Free Software Foundation, Inc.
  * Copyright (C) 2015 Ettus Research LLC
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/radioInterfaceMulti.cpp b/Transceiver52M/radioInterfaceMulti.cpp
index 17a015b..0208e82 100644
--- a/Transceiver52M/radioInterfaceMulti.cpp
+++ b/Transceiver52M/radioInterfaceMulti.cpp
@@ -5,6 +5,8 @@
  *
  * Author: Tom Tsou <tom.tsou@ettus.com>
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/radioInterfaceResamp.cpp b/Transceiver52M/radioInterfaceResamp.cpp
index 8ae4aa1..e2f69f2 100644
--- a/Transceiver52M/radioInterfaceResamp.cpp
+++ b/Transceiver52M/radioInterfaceResamp.cpp
@@ -6,6 +6,8 @@
  *
  * Author: Tom Tsou <tom@tsou.cc>
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/radioVector.cpp b/Transceiver52M/radioVector.cpp
index 2e3af9d..ad40a11 100644
--- a/Transceiver52M/radioVector.cpp
+++ b/Transceiver52M/radioVector.cpp
@@ -4,6 +4,8 @@
  *
  * Copyright 2011 Free Software Foundation, Inc.
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/radioVector.h b/Transceiver52M/radioVector.h
index 0566123..0a14a4d 100644
--- a/Transceiver52M/radioVector.h
+++ b/Transceiver52M/radioVector.h
@@ -4,6 +4,8 @@
  *
  * Copyright 2011 Free Software Foundation, Inc.
  *
+ * SPDX-License-Identifier: AGPL-3.0+
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
diff --git a/Transceiver52M/sigProcLib.cpp b/Transceiver52M/sigProcLib.cpp
index 1042dbb..011ddff 100644
--- a/Transceiver52M/sigProcLib.cpp
+++ b/Transceiver52M/sigProcLib.cpp
@@ -1,6 +1,8 @@
 /*
 * Copyright 2008, 2011 Free Software Foundation, Inc.
 *
+* SPDX-License-Identifier: AGPL-3.0+
+*
 * This software is distributed under the terms of the GNU Affero Public License.
 * See the COPYING file in the main directory for details.
 *