1 files changed, 74 insertions, 0 deletions
diff --git a/dpd/src/phase_align.py b/dpd/src/phase_align.py
new file mode 100644
index 0000000..f03184b
--- /dev/null
+++ b/dpd/src/phase_align.py
@@ -0,0 +1,74 @@
+import datetime
+import os
+import logging
+logging_path = os.path.dirname(logging.getLoggerClass().root.handlers[0].baseFilename)
+
+import numpy as np
+from scipy import signal, optimize
+import sys
+import matplotlib.pyplot as plt
+
+
+def phase_align(sig, ref_sig):
+    """Do phase alignment for sig relative to the reference signal
+    ref_sig.
+
+    Returns the aligned signal"""
+
+    angle_diff = (np.angle(sig) - np.angle(ref_sig)) % (2. * np.pi)
+
+    real_diffs = np.cos(angle_diff)
+    imag_diffs = np.sin(angle_diff)
+
+    if logging.getLogger().getEffectiveLevel() == logging.DEBUG:
+        dt = datetime.datetime.now().isoformat()
+        fig_path = logging_path + "/" + dt + "_phase_align.pdf"
+
+        plt.subplot(511)
+        plt.hist(angle_diff, bins=60, label="Angle Diff")
+        plt.xlabel("Angle")
+        plt.ylabel("Count")
+        plt.legend(loc=4)
+
+        plt.subplot(512)
+        plt.hist(real_diffs, bins=60, label="Real Diff")
+        plt.xlabel("Real Part")
+        plt.ylabel("Count")
+        plt.legend(loc=4)
+
+        plt.subplot(513)
+        plt.hist(imag_diffs, bins=60, label="Imaginary Diff")
+        plt.xlabel("Imaginary Part")
+        plt.ylabel("Count")
+        plt.legend(loc=4)
+
+        plt.subplot(514)
+        plt.plot(np.angle(ref_sig[:128]), label="ref_sig")
+        plt.plot(np.angle(sig[:128]), label="sig")
+        plt.xlabel("Angle")
+        plt.ylabel("Sample")
+        plt.legend(loc=4)
+
+    real_diff = np.median(real_diffs)
+    imag_diff = np.median(imag_diffs)
+
+    angle = np.angle(real_diff + 1j * imag_diff)
+
+    logging.debug(
+        "Compensating phase by {} rad, {} degree. real median {}, imag median {}".format(
+        angle, angle*180./np.pi, real_diff, imag_diff
+    ))
+    sig = sig * np.exp(1j * -angle)
+
+    if logging.getLogger().getEffectiveLevel() == logging.DEBUG:
+        plt.subplot(515)
+        plt.plot(np.angle(ref_sig[:128]), label="ref_sig")
+        plt.plot(np.angle(sig[:128]), label="sig")
+        plt.xlabel("Angle")
+        plt.ylabel("Sample")
+        plt.legend(loc=4)
+        plt.tight_layout()
+        plt.savefig(fig_path)
+        plt.clf()
+
+    return sig