iqbal: Import new module to deal with IQ balance correction/optimization

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

2 files changed, 78 insertions, 1 deletions

diff --git a/include/osmocom/dsp/Makefile.am b/include/osmocom/dsp/Makefile.am
index 5a6534f..24c4c4a 100644
--- a/include/osmocom/dsp/Makefile.am
+++ b/include/osmocom/dsp/Makefile.am
@@ -1,3 +1,3 @@
-osmodsp_HEADERS = cfile.h cxvec.h cxvec_math.h
+osmodsp_HEADERS = cfile.h cxvec.h cxvec_math.h iqbal.h
 
 osmodspdir = $(includedir)/osmocom/dsp
diff --git a/include/osmocom/dsp/iqbal.h b/include/osmocom/dsp/iqbal.h
new file mode 100644
index 0000000..c7f7e60
--- /dev/null
+++ b/include/osmocom/dsp/iqbal.h
@@ -0,0 +1,77 @@
+/*
+ * iqbal.h
+ *
+ * IQ balance correction / estimation utilities
+ *
+ * Copyright (C) 2013  Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __OSMO_DSP_IQBAL_H__
+#define __OSMO_DSP_IQBAL_H__
+
+/*! \defgroup iqbal IQ balance utilities
+ *  @{
+ */
+
+/*! \file iqbal.h
+ *  \brief Osmocom IQ balance utils header
+ */
+
+#include <complex.h>
+
+#include <osmocom/dsp/cxvec.h>
+
+
+/* IQ balance correction and estimation */
+
+void osmo_iqbal_fix(float complex *out, float complex *in, unsigned int len,
+                    float mag, float phase);
+
+struct osmo_cxvec *
+osmo_iqbal_cxvec_fix(const struct osmo_cxvec *in, float mag, float phase,
+                     struct osmo_cxvec *out);
+
+float
+osmo_iqbal_estimate(const float complex *data,
+                    int fft_size, int fft_count);
+
+float
+osmo_iqbal_cxvec_estimate(const struct osmo_cxvec *sig,
+                          int fft_size, int fft_count);
+
+
+/* IQ balance optimization */ 
+
+/*! \brief Processing options for the IQ balance optimization algorithm */
+struct osmo_iqbal_opts {
+	int fft_size;   	/*!< \brief FFT size to use */
+	int fft_count;  	/*!< \brief Number of FFT to use */
+	int max_iter;   	/*!< \brief Max # iterations per pass */
+	int start_at_prev;	/*!< \brief Use prev values as starting point */
+};
+
+extern const struct osmo_iqbal_opts osmo_iqbal_default_opts;
+
+int
+osmo_iqbal_cxvec_optimize(const struct osmo_cxvec *sig, float *mag, float *phase,
+                          const struct osmo_iqbal_opts *opts);
+
+/*! @} */
+
+#endif /* __OSMO_DSP_IQBAL_H__ */