# -*- coding: utf-8 -*- # # DPD Calculation Engine, utilities for working with DAB signals. # # http://www.opendigitalradio.org # Licence: The MIT License, see notice at the end of this file import datetime import os import logging logging_path = os.path.dirname(logging.getLoggerClass().root.handlers[0].baseFilename) import numpy as np import scipy import matplotlib matplotlib.use('agg') import matplotlib.pyplot as plt import src.subsample_align as sa import src.phase_align as pa from scipy import signal class Dab_Util: """Collection of methods that can be applied to an array complex IQ samples of a DAB signal """ def __init__(self, sample_rate): """ :param sample_rate: sample rate [sample/sec] to use for calculations """ self.sample_rate = sample_rate self.dab_bandwidth = 1536000 #Bandwidth of a dab signal self.frame_ms = 96 #Duration of a Dab frame def lag(self, sig_orig, sig_rec): """ Find lag between two signals Args: sig_orig: The signal that has been sent sig_rec: The signal that has been recored """ off = sig_rec.shape[0] c = np.abs(signal.correlate(sig_orig, sig_rec)) if logging.getLogger().getEffectiveLevel() == logging.DEBUG: dt = datetime.datetime.now().isoformat() corr_path = (logging_path + "/" + dt + "_tx_rx_corr.pdf") plt.plot(c, label="corr") plt.legend() plt.savefig(corr_path) plt.clf() return np.argmax(c) - off + 1 def lag_upsampling(self, sig_orig, sig_rec, n_up): if n_up != 1: sig_orig_up = signal.resample(sig_orig, sig_orig.shape[0] * n_up) sig_rec_up = signal.resample(sig_rec, sig_rec.shape[0] * n_up) else: sig_orig_up = sig_orig sig_rec_up = sig_rec l = self.lag(sig_orig_up, sig_rec_up) l_orig = float(l) / n_up return l_orig def subsample_align_upsampling(self, sig_tx, sig_rx, n_up=32): """ Returns an aligned version of sig_tx and sig_rx by cropping and subsample alignment Using upsampling """ assert(sig_tx.shape[0] == sig_rx.shape[0]) if sig_tx.shape[0] % 2 == 1: sig_tx = sig_tx[:-1] sig_rx = sig_rx[:-1] sig1_up = signal.resample(sig_tx, sig_tx.shape[0] * n_up) sig2_up = signal.resample(sig_rx, sig_rx.shape[0] * n_up) off_meas = self.lag_upsampling(sig2_up, sig1_up, n_up=1) off = int(abs(off_meas)) if off_meas > 0: sig1_up = sig1_up[:-off] sig2_up = sig2_up[off:] elif off_meas < 0: sig1_up = sig1_up[off:] sig2_up = sig2_up[:-off] sig_tx = signal.resample(sig1_up, sig1_up.shape[0] / n_up).astype(np.complex64) sig_rx = signal.resample(sig2_up, sig2_up.shape[0] / n_up).astype(np.complex64) return sig_tx, sig_rx def subsample_align(self, sig_tx, sig_rx): """ Returns an aligned version of sig_tx and sig_rx by cropping and subsample alignment """ if logging.getLogger().getEffectiveLevel() == logging.DEBUG: dt = datetime.datetime.now().isoformat() fig_path = logging_path + "/" + dt + "_sync_raw.pdf" fig, axs = plt.subplots(2) axs[0].plot(np.abs(sig_tx[:128]), label="TX Frame") axs[0].plot(np.abs(sig_rx[:128]), label="RX Frame") axs[0].set_title("Raw Data") axs[0].set_ylabel("Amplitude") axs[0].set_xlabel("Samples") axs[0].legend(loc=4) axs[1].plot(np.real(sig_tx[:128]), label="TX Frame") axs[1].plot(np.real(sig_rx[:128]), label="RX Frame") axs[1].set_title("Raw Data") axs[1].set_ylabel("Real Part") axs[1].set_xlabel("Samples") axs[1].legend(loc=4) fig.tight_layout() fig.savefig(fig_path) fig.clf() off_meas = self.lag_upsampling(sig_rx, sig_tx, n_up=1) off = int(abs(off_meas)) logging.debug("sig_tx_orig: {} {}, sig_rx_orig: {} {}, offset {}".format( len(sig_tx), sig_tx.dtype, len(sig_rx), sig_rx.dtype, off_meas)) if off_meas > 0: sig_tx = sig_tx[:-off] sig_rx = sig_rx[off:] elif off_meas < 0: sig_tx = sig_tx[off:] sig_rx = sig_rx[:-off] if off % 2 == 1: sig_tx = sig_tx[:-1] sig_rx = sig_rx[:-1] if logging.getLogger().getEffectiveLevel() == logging.DEBUG: dt = datetime.datetime.now().isoformat() fig_path = logging_path + "/" + dt + "_sync_sample_aligned.pdf" fig, axs = plt.subplots(2) axs[0].plot(np.abs(sig_tx[:128]), label="TX Frame") axs[0].plot(np.abs(sig_rx[:128]), label="RX Frame") axs[0].set_title("Sample Aligned Data") axs[0].set_ylabel("Amplitude") axs[0].set_xlabel("Samples") axs[0].legend(loc=4) axs[1].plot(np.real(sig_tx[:128]), label="TX Frame") axs[1].plot(np.real(sig_rx[:128]), label="RX Frame") axs[1].set_ylabel("Real Part") axs[1].set_xlabel("Samples") axs[1].legend(loc=4) fig.tight_layout() fig.savefig(fig_path) fig.clf() sig_rx = sa.subsample_align(sig_rx, sig_tx) if logging.getLogger().getEffectiveLevel() == logging.DEBUG: dt = datetime.datetime.now().isoformat() fig_path = logging_path + "/" + dt + "_sync_subsample_aligned.pdf" fig, axs = plt.subplots(2) axs[0].plot(np.abs(sig_tx[:128]), label="TX Frame") axs[0].plot(np.abs(sig_rx[:128]), label="RX Frame") axs[0].set_title("Subsample Aligned") axs[0].set_ylabel("Amplitude") axs[0].set_xlabel("Samples") axs[0].legend(loc=4) axs[1].plot(np.real(sig_tx[:128]), label="TX Frame") axs[1].plot(np.real(sig_rx[:128]), label="RX Frame") axs[1].set_ylabel("Real Part") axs[1].set_xlabel("Samples") axs[1].legend(loc=4) fig.tight_layout() fig.savefig(fig_path) fig.clf() sig_rx = pa.phase_align(sig_rx, sig_tx) if logging.getLogger().getEffectiveLevel() == logging.DEBUG: dt = datetime.datetime.now().isoformat() fig_path = logging_path + "/" + dt + "_sync_phase_aligned.pdf" fig, axs = plt.subplots(2) axs[0].plot(np.abs(sig_tx[:128]), label="TX Frame") axs[0].plot(np.abs(sig_rx[:128]), label="RX Frame") axs[0].set_title("Phase Aligned") axs[0].set_ylabel("Amplitude") axs[0].set_xlabel("Samples") axs[0].legend(loc=4) axs[1].plot(np.real(sig_tx[:128]), label="TX Frame") axs[1].plot(np.real(sig_rx[:128]), label="RX Frame") axs[1].set_ylabel("Real Part") axs[1].set_xlabel("Samples") axs[1].legend(loc=4) fig.tight_layout() fig.savefig(fig_path) fig.clf() logging.debug("Sig1_cut: %d %s, Sig2_cut: %d %s, off: %d" % (len(sig_tx), sig_tx.dtype, len(sig_rx), sig_rx.dtype, off)) return sig_tx, sig_rx def fromfile(self, filename, offset=0, length=None): if length is None: return np.memmap(filename, dtype=np.complex64, mode='r', offset=64/8*offset) else: return np.memmap(filename, dtype=np.complex64, mode='r', offset=64/8*offset, shape=length) # 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.