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Diffstat (limited to 'dpd/src/Measure.py')
| -rw-r--r-- | dpd/src/Measure.py | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/dpd/src/Measure.py b/dpd/src/Measure.py new file mode 100644 index 0000000..e4fa8a2 --- /dev/null +++ b/dpd/src/Measure.py @@ -0,0 +1,123 @@ +# -*- coding: utf-8 -*- + +import sys +import socket +import struct +import numpy as np +import logging +import src.Dab_Util as DU + +class Measure: + """Collect Measurement from DabMod""" + def __init__(self, samplerate, port, num_samples_to_request): + logging.info("Instantiate Measure object") + self.samplerate = samplerate + self.sizeof_sample = 8 # complex floats + self.port = port + self.num_samples_to_request = num_samples_to_request + + def _recv_exact(self, sock, num_bytes): + """Receive an exact number of bytes from a socket. This is + a wrapper around sock.recv() that can return less than the number + of requested bytes. + + Args: + sock (socket): Socket to receive data from. + num_bytes (int): Number of bytes that will be returned. + """ + bufs = [] + while num_bytes > 0: + b = sock.recv(num_bytes) + if len(b) == 0: + break + num_bytes -= len(b) + bufs.append(b) + return b''.join(bufs) + + def get_samples(self): + """Connect to ODR-DabMod, retrieve TX and RX samples, load + into numpy arrays, and return a tuple + (tx_timestamp, tx_samples, rx_timestamp, rx_samples) + where the timestamps are doubles, and the samples are numpy + arrays of complex floats, both having the same size + """ + s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) + s.connect(('localhost', self.port)) + + logging.debug("Send version") + s.sendall(b"\x01") + + logging.debug("Send request for {} samples".format(self.num_samples_to_request)) + s.sendall(struct.pack("=I", self.num_samples_to_request)) + + logging.debug("Wait for TX metadata") + num_samps, tx_second, tx_pps = struct.unpack("=III", self._recv_exact(s, 12)) + tx_ts = tx_second + tx_pps / 16384000.0 + + if num_samps > 0: + logging.debug("Receiving {} TX samples".format(num_samps)) + txframe_bytes = self._recv_exact(s, num_samps * self.sizeof_sample) + txframe = np.fromstring(txframe_bytes, dtype=np.complex64) + else: + txframe = np.array([], dtype=np.complex64) + + logging.debug("Wait for RX metadata") + rx_second, rx_pps = struct.unpack("=II", self._recv_exact(s, 8)) + rx_ts = rx_second + rx_pps / 16384000.0 + + if num_samps > 0: + logging.debug("Receiving {} RX samples".format(num_samps)) + rxframe_bytes = self._recv_exact(s, num_samps * self.sizeof_sample) + rxframe = np.fromstring(rxframe_bytes, dtype=np.complex64) + else: + rxframe = np.array([], dtype=np.complex64) + + # Normalize received signal with sent signal + rx_median = np.median(np.abs(rxframe)) + rxframe = rxframe / rx_median * np.median(np.abs(txframe)) + + if logging.getLogger().getEffectiveLevel() == logging.DEBUG: + logging.debug("txframe: min %f, max %f, median %f" % + (np.min(np.abs(txframe)), + np.max(np.abs(txframe)), + np.median(np.abs(txframe)))) + + logging.debug("rxframe: min %f, max %f, median %f" % + (np.min(np.abs(rxframe)), + np.max(np.abs(rxframe)), + np.median(np.abs(rxframe)))) + + logging.debug("Disconnecting") + s.close() + + du = DU.Dab_Util(self.samplerate) + txframe_aligned, rxframe_aligned = du.subsample_align(txframe, rxframe) + + logging.info( + "Measurement done, tx %d %s, rx %d %s, tx aligned %d %s, rx aligned %d %s" + % (len(txframe), txframe.dtype, len(rxframe), rxframe.dtype, + len(txframe_aligned), txframe_aligned.dtype, len(rxframe_aligned), rxframe_aligned.dtype) ) + + return txframe_aligned, tx_ts, rxframe_aligned, rx_ts, rx_median + +# 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. |