1 files changed, 124 insertions, 0 deletions
diff --git a/python/dpd/Model_PM.py b/python/dpd/Model_PM.py
new file mode 100644
index 0000000..7b80bf3
--- /dev/null
+++ b/python/dpd/Model_PM.py
@@ -0,0 +1,124 @@
+# -*- coding: utf-8 -*-
+#
+# DPD Computation Engine, model implementation for Amplitude and not Phase
+#
+# http://www.opendigitalradio.org
+# Licence: The MIT License, see notice at the end of this file
+
+import datetime
+import os
+import logging
+import numpy as np
+import matplotlib.pyplot as plt
+
+
+def is_npfloat32(array):
+    assert isinstance(array, np.ndarray), type(array)
+    assert array.dtype == np.float32, array.dtype
+    assert array.flags.contiguous
+    assert not any(np.isnan(array))
+
+
+def check_input_get_next_coefs(tx_dpd, phase_diff):
+    is_npfloat32(tx_dpd)
+    is_npfloat32(phase_diff)
+
+
+class Model_PM:
+    """Calculates new coefficients using the measurement and the previous
+    coefficients"""
+
+    def __init__(self,
+                 c,
+                 learning_rate_pm=1,
+                 plot=False):
+        self.c = c
+
+        self.learning_rate_pm = learning_rate_pm
+        self.plot = plot
+
+    def _plot(self, tx_dpd, phase_diff, coefs_pm, coefs_pm_new):
+        if self.plot and self.c.plot_location is not None:
+            tx_range, phase_diff_est = self.calc_line(coefs_pm, 0, 0.6)
+            tx_range_new, phase_diff_est_new = self.calc_line(coefs_pm_new, 0, 0.6)
+
+            dt = datetime.datetime.now().isoformat()
+            fig_path = self.c.plot_location + "/" + dt + "_Model_PM.png"
+            sub_rows = 1
+            sub_cols = 1
+            fig = plt.figure(figsize=(sub_cols * 6, sub_rows / 2. * 6))
+            i_sub = 0
+
+            i_sub += 1
+            ax = plt.subplot(sub_rows, sub_cols, i_sub)
+            ax.plot(tx_range, phase_diff_est,
+                    label="Estimated Phase Diff",
+                    alpha=0.3,
+                    color="gray")
+            ax.plot(tx_range_new, phase_diff_est_new,
+                    label="New Estimated Phase Diff",
+                    color="red")
+            ax.scatter(tx_dpd, phase_diff,
+                       label="Binned Data",
+                       color="blue",
+                       s=1)
+            ax.set_title("Model_PM")
+            ax.set_xlabel("TX Amplitude")
+            ax.set_ylabel("Phase DIff")
+            ax.legend(loc=4)
+
+            fig.tight_layout()
+            fig.savefig(fig_path)
+            plt.close(fig)
+
+    def _discard_small_values(self, tx_dpd, phase_diff):
+        """ Assumes that the phase for small tx amplitudes is zero"""
+        mask = tx_dpd < self.c.MPM_tx_min
+        phase_diff[mask] = 0
+        return tx_dpd, phase_diff
+
+    def poly(self, sig):
+        return np.array([sig ** i for i in range(0, 5)]).T
+
+    def fit_poly(self, tx_abs, phase_diff):
+        return np.linalg.lstsq(self.poly(tx_abs), phase_diff, rcond=None)[0]
+
+    def calc_line(self, coefs, min_amp, max_amp):
+        tx_range = np.linspace(min_amp, max_amp)
+        phase_diff = np.sum(self.poly(tx_range) * coefs, axis=1)
+        return tx_range, phase_diff
+
+    def get_next_coefs(self, tx_dpd, phase_diff, coefs_pm):
+        """Calculate the next AM/PM coefficients using the extracted
+        statistic of TX amplitude and phase difference"""
+        tx_dpd, phase_diff = self._discard_small_values(tx_dpd, phase_diff)
+        check_input_get_next_coefs(tx_dpd, phase_diff)
+
+        coefs_pm_new = self.fit_poly(tx_dpd, phase_diff)
+
+        coefs_pm_new = coefs_pm + self.learning_rate_pm * (coefs_pm_new - coefs_pm)
+        self._plot(tx_dpd, phase_diff, coefs_pm, coefs_pm_new)
+
+        return coefs_pm_new
+
+# The MIT License (MIT)
+#
+# Copyright (c) 2017 Andreas Steger
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.