iqgen: bug fixes

Fixed bugs in IQgen components. Reworked code for unit testing.

Author: valeri-atamaniouk

.gitignore

@@ -56,3 +56,8 @@ tests/test_data_old*
 .project
 .cproject
 .settings/
+
+# Coverage
+.coverage
+htmlcov/
+

peregrine/iqgen/bits/amplitude_base.py

@@ -206,7 +206,7 @@ def convertUnits2SNR(value, units, noiseParams):
       snrDb = 10 * numpy.log10(snr)
     elif units == AmplitudeBase.UNITS_SNR_DB:
       snrDb = value
-    else:
+    else:  # pragma: no cover
       assert False
     return snrDb
 
@@ -240,6 +240,6 @@ def convertUnits2Amp(value, units, noiseParams):
       snrDb = value
       snr = 10. ** (0.1 * snrDb)
       amp = numpy.sqrt(4. * snr / freqTimesTau) * noiseSigma
-    else:
+    else:  # pragma: no cover
       assert False
     return amp

peregrine/iqgen/bits/doppler_base.py

@@ -181,12 +181,8 @@ def computeBatch(self,
     -------
     signal : numpy.ndarray(n_samples, dtype=float)
       Generated samples
-    userTimeX_s : float
-      End of interval time in seconds
-    chipAll_idx : numpy.ndarray(n_samples, dtype=float)
-      Code chip phases for the samples
-    chips : numpy.ndarray(n_samples, dtype=int)
-      Code combined with data
+    dopplerAll_hz : numpy.ndarray(n_samples, dtype=float)
+      Doppler values in Hz if debug is enabled
     '''
 
     userTimeAll_s = self.applySignalDelays(userTimeAll_s, carrierSignal)

peregrine/iqgen/bits/doppler_sine.py

@@ -65,21 +65,6 @@ def __str__(self):
         format(self.distance0_m, self.tec_epm2, self.speed0_mps,
                self.amplutude_mps, self.period_s, self.codeDopplerIgnored)
 
-  def __repr__(self):
-    '''
-    Constructs python expression presentation of object.
-
-    Returns
-    -------
-    string
-      Python expression presentation of object
-    '''
-    return "Doppler({}, {}, {}, {}, {})".format(self.distance0_m,
-                                                self.tec_epm2,
-                                                self.speed0_mps,
-                                                self.amplutude_mps,
-                                                self.period_s)
-
   def computeDistanceM(self, svTime_s):
     '''
     Computes doppler shift in meters.

peregrine/iqgen/bits/encoder_base.py

@@ -46,7 +46,7 @@ def __init__(self, bufferSize=1000, attDb=0.):
 
   def addSamples(self, sample_array):
     '''
-    Extracts samples of the supported band and coverts them into bit stream.
+    Extracts samples of the supported band and converts them into bit stream.
 
     Parameters
     ----------
@@ -58,7 +58,7 @@ def addSamples(self, sample_array):
     numpy.ndarray(dtype=numpy.uint8)
       Array of type uint8 containing the encoded data.
     '''
-    return Encoder.EMPTY_RESULT
+    raise NotImplementedError()
 
   def flush(self):
     '''
@@ -70,10 +70,15 @@ def flush(self):
       Array of type uint8 containing the encoded data.
     '''
     if self.n_bits > 0 and self.n_bits % 8 != 0:
-      self.bits += (8 - self.n_bits % 8)
-    res = numpy.packbits(self.bits[0:self.n_bits])
-    self.n_bits = 0
-    return res
+      self.n_bits += (8 - self.n_bits % 8)
+    if self.n_bits:
+      res = numpy.packbits(self.bits[0:self.n_bits])
+      self.bits[0:self.n_bits].fill(0)
+      self.n_bits = 0
+      return res
+    else:
+      # Pack bits returns incorrect result in case of empty source bit set.
+      return Encoder.EMPTY_RESULT
 
   def encodeValues(self):
     '''
@@ -91,6 +96,7 @@ def encodeValues(self):
     n_left = self.n_bits - n_offset
     res = numpy.packbits(self.bits[0: n_offset])
     self.bits[0:n_left] = self.bits[n_offset:n_offset + n_left]
+    self.bits[n_left:].fill(0)
     self.n_bits = n_left
     return res
 

peregrine/iqgen/bits/encoder_gps.py

@@ -14,7 +14,6 @@
 
 """
 
-from peregrine.iqgen.bits.encoder_base import Encoder
 from peregrine.iqgen.bits.encoder_1bit import BandBitEncoder
 from peregrine.iqgen.bits.encoder_1bit import TwoBandsBitEncoder
 from peregrine.iqgen.bits.encoder_2bits import BandTwoBitsEncoder

peregrine/iqgen/bits/filter_bandpass.py

@@ -41,8 +41,8 @@ def __init__(self, outputConfig, frequency_hz, bw_hz=1e6):
 
     self.bw_hz = bw_hz
     self.frequency_hz = frequency_hz
-    passBand_hz = bw_hz * 0.5 / outputConfig.SAMPLE_RATE_HZ
-    stopBand_hz = bw_hz * 0.6 / outputConfig.SAMPLE_RATE_HZ
+    passBand_hz = bw_hz
+    stopBand_hz = bw_hz * 1.2
     mult = 2. / outputConfig.SAMPLE_RATE_HZ
     order, wn = cheb2ord(wp=[(frequency_hz - passBand_hz) * mult,
                              (frequency_hz + passBand_hz) * mult],
@@ -52,7 +52,7 @@ def __init__(self, outputConfig, frequency_hz, bw_hz=1e6):
                          gstop=self.stopBandAtt_dbhz,
                          analog=False)
 
-    b, a = cheby2(order,  # Order of the filter
+    b, a = cheby2(order + 1,  # Order of the filter
                   # Minimum attenuation required in the stop band in dB
                   self.stopBandAtt_dbhz,
                   wn,

peregrine/iqgen/bits/filter_base.py

@@ -24,9 +24,9 @@ def __init__(self, passBandAtt_dbhz, stopBandAtt_dbhz):
     Parameters
     ----------
     passBandAtt_dbhz : float
-      Pass band attenutation in dB*Hz
+      Pass band attenuation in dB*Hz
     stopBandAtt_dbhz: float
-      Stop band attenutation in dB*Hz
+      Stop band attenuation in dB*Hz
     '''
     self.passBandAtt_dbhz = passBandAtt_dbhz
     self.stopBandAtt_dbhz = stopBandAtt_dbhz

peregrine/iqgen/bits/filter_lowpass.py

@@ -51,19 +51,23 @@ def __init__(self, outputConfig, frequency_hz=0.):
     '''
     super(LowPassFilter, self).__init__(3., 40.)
 
-    self.bw_hz = 1e3
-    passBand_hz = self.bw_hz / outputConfig.SAMPLE_RATE_HZ
-    stopBand_hz = self.bw_hz * 1.1 / outputConfig.SAMPLE_RATE_HZ
-    mult = 2. / outputConfig.SAMPLE_RATE_HZ
-    order, wn = cheb2ord(wp=passBand_hz * mult,
-                         ws=stopBand_hz * mult,
+    self.bw_hz = 1e6
+    passBand_hz = frequency_hz + self.bw_hz
+    stopBand_hz = frequency_hz + self.bw_hz * 1.2
+
+    nyqFreq_s = 2. / outputConfig.SAMPLE_RATE_HZ  # 1.0 /Nyquist frequency
+    wp = passBand_hz * nyqFreq_s
+    ws = stopBand_hz * nyqFreq_s
+
+    order, wn = cheb2ord(wp=wp,
+                         ws=ws,
                          gpass=self.passBandAtt_dbhz,
                          gstop=self.stopBandAtt_dbhz,
                          analog=False)
     self.order = order
     self.wn = wn
 
-    b, a = cheby2(order,  # Order of the filter
+    b, a = cheby2(order + 1,  # Order of the filter
                   # Minimum attenuation required in the stop band in dB
                   self.stopBandAtt_dbhz,
                   wn,

peregrine/iqgen/bits/message_block.py

@@ -31,12 +31,9 @@ def __init__(self, messageData):
       Array with message bits. Bit 0 is encoded with 1, bit 1 is encoded with -1
     '''
     super(Message, self).__init__()
-    self.messageData = messageData[:]
-    self.messageLen = len(self.messageData)
-    tmp = numpy.asarray(self.messageData, dtype=numpy.uint8)
-    tmp *= -2
-    tmp -= 1
-    self.bits = tmp.astype(numpy.uint8)
+    bits = numpy.asarray(messageData) < 0
+    self.messageLen = bits.shape[0]
+    self.bits = bits.astype(numpy.uint8)
 
   def __str__(self, *args, **kwargs):
     '''
@@ -66,20 +63,3 @@ def getDataBits(self, dataAll_idx):
     # numpy.take degrades performance a lot over time.
     # return numpy.take(self.bits, dataAll_idx , mode='wrap')
     return self.bits[dataAll_idx % self.messageLen]
-
-  def getBit(self, bitIndex):
-    '''
-    Provides bit at a given index
-
-    Parameters
-    ----------
-    bitIndex : long
-      Bit index
-
-    Returns
-    -------
-    int
-      Bit value: 1 for bit 0 and -1 for bit 1
-    '''
-
-    return self.messageData[bitIndex % self.messageLen]