def resampling(self, ch, fs):
self.myprint("original samplerate = ", fs)
if fs == self.fs:
self.myprint("resampling not required")
else:
self.myprint("resampling to ", self.fs)
resample_fs_id = str(self.fs)
original_fs_id = str(fs)
has_valid_filter_specs = resample_fs_id in self.filter_specs and\
original_fs_id in self.filter_specs[resample_fs_id]
if has_valid_filter_specs:
try:
self.loaded_channels[ch] = signal.upfirdn(
self.filter_specs[resample_fs_id][original_fs_id]["numerator"],
self.loaded_channels[ch],
self.filter_specs[resample_fs_id][original_fs_id]["up"],
self.filter_specs[resample_fs_id][original_fs_id]["down"],
)
if self.fs == 100:
if fs == 256 or fs == 512: # Matlab creates a filtercascade which requires the 128 Hz filter be applied afterwards
self.loaded_channels[ch] = signal.upfirdn(
self.filter_specs[resample_fs_id]["128"]["numerator"],
self.loaded_channels[ch],
self.filter_specs[resample_fs_id]["128"]["up"],
self.filter_specs[resample_fs_id]["128"]["down"],
)
except:
self.myprint('Warning: Exception caught during resampling. Using automated resampling filter '
'coefficients.')
self.loaded_channels[ch] = signal.resample_poly(self.loaded_channels[ch], self.fs, fs, axis=0,
window=('kaiser', 5.0))
else:
self.loaded_channels[ch] = signal.resample_poly(self.loaded_channels[ch], self.fs, fs, axis=0,
window=('kaiser', 5.0))
def modulate(self, bitsToModulate):
bitsToModulate = [1 if x > 0 else -1 for x in bitsToModulate]
N = int(len(bitsToModulate) / 2)
signalI = signal.upfirdn([1], bitsToModulate[0::2], self.symbolLength)
signalQ = signal.upfirdn([1], bitsToModulate[1::2], self.symbolLength)
filteredI = np.convolve(signalI, self.psfFilter)
signalI = filteredI[int(self.symbolLength * 5): - int(self.symbolLength * 5) + 1]
filteredQ = np.convolve(signalQ, self.psfFilter)
signalQ = filteredQ[int(self.symbolLength * 5): - int(self.symbolLength * 5) + 1]
t = np.arange(0, N * self.symbolLength * self.sampleTime, self.sampleTime)
return np.multiply(signalI, np.cos(2 * np.pi * self.carrierFreq * t + self.fi)) - 1j * np.multiply(signalQ, np.sin(2 * np.pi * self.carrierFreq * t + self.fi))
def modulate(self, coded_bits: np.ndarray) -> np.ndarray:
"""
Take a series of bits (the baseband digital signal) and modulate it into an analog bandpass
signal at the carrier frequency using IQ modulation.
Coded bits -> QPSK Map -> Upsample Comb -> RRC Filter -> IQ Modulation -> Waveform (sampled analog signal)
:param coded_bits: digital baseband signal as series of bits (probably encoded)
:return: sampled analog signal of the modulated waveform
"""
# map bits to QPSK symbols
qam_symbols = self._modem.modulate(coded_bits)
# upsample the qam symbols to a comb signal and apply pulse shaping rrc filter
from scipy.signal import upfirdn
baseband_signal = upfirdn(self._rrc_fir, qam_symbols,
self._upsmple_factor)
baseband_signal_t = np.arange(len(baseband_signal)) / self._f_sample
# compute the in-phase and quadrature components of the signal
i_quad = baseband_signal.real * np.cos(
self._w_carrier * baseband_signal_t)
q_quad = baseband_signal.imag * np.sin(
self._w_carrier * baseband_signal_t) * (-1)
# sum the quadrature signals to get a real-valued signal for transmission
signal = i_quad + q_quad
logging.info('Modulated {}-bit coded signal with {} samples'.format(
len(coded_bits), len(signal)))
return signal
def test_length_factors(self, len_h, len_x, up, down, expected):
# gh-9844: weird factors
h = np.zeros(len_h)
h[0] = 1.
x = np.ones(len_x)
y = upfirdn(h, x, up, down)
assert_allclose(y, expected)
def upconvert(x, sps, fc, fs=2.0, g=None):
"""Upconvert a complex baseband signal with pulse shaping.
This function supports upconversion by an integer factor. For a more general
passband conversion (but without pulse shaping), see :func:`arlpy.signal.bb2pb`.
If the carrier frequency is 0, the upsampled (at passband sampling rate) and
pulse shaped complex baseband data is returned. If the pulse shape is None,
a rectangular pulse shape is assumed.
The upconversion process introduces a group delay depending on the pulse shaping
filter. It is usually (len(g)-1)/2 passband samples. When g is None, the group
delay is (sps-1)/2 passband samples.
:param x: complex baseband data
:param sps: number of passband samples per baseband symbol
:param fc: carrier frequency in Hz
:param fs: passband sampling rate
:param g: pulse shaping filter
>>> import arlpy
>>> rrc = arlpy.comms.rrcosfir(0.25, 6)
>>> bb = arlpy.comms.modulate(arlpy.comms.random_data(100), arlpy.comms.psk())
>>> pb = arlpy.comms.upconvert(bb, 6, 27000, 108000, rrc)
"""
x = _np.asarray(x, dtype=_np.complex)
if g is None:
y = _np.repeat(x, sps) / _np.sqrt(sps)
else:
y = _sp.upfirdn(g, x, up=sps)
if fc != 0:
y *= _sqrt(2) * _np.exp(2j * _pi * fc * _time(y, fs))
y = y.real
return y
def get_samples(self, n: int) -> np.ndarray:
h = np.empty(n)
# Fill out the first values with the fading value from last call to
# `get_samples`
number_from_last = min(self.prev_left, n)
if number_from_last != 0:
h[:number_from_last] = np.repeat(self.prev_alpha, number_from_last)
n -= number_from_last
self.prev_left -= number_from_last
if n <= 0:
return h
# Pull out enough values from Rayleigh to satisfy n samples
alpha = rayleigh(int(np.ceil(n / self.samples_per_realization)))
# Upsample alpha so that each value is repeated samples_per_realization
# times
upsampled = signal.upfirdn(h=np.ones(self.samples_per_realization),
x=alpha,
up=self.samples_per_realization)
# Copy the needed samples into h
h[number_from_last:] = upsampled[:n]
# Check that some values from up sampled should be added to the next
# `get_sampled` call
nr_leftover = len(upsampled) - n
if nr_leftover > 0:
self.prev_left = nr_leftover
self.prev_alpha = alpha[-1]
return h
def generate_symbols(n_symbols,oversamp=2,mod='qpsk', same_pkt = 0):
#sps=2 # need to regenerate filter to change it
sps=oversamp
h=sps_filter[int(sps)]
skp=int(np.floor(h.size)/2)
n_symbols=int((n_symbols)) #/sps
# rcosdesign(0.2,10,2)
order=mod_dict[mod]['order']
const=mod_dict[mod]['constellation']
if same_pkt == 0:
symbs=np.random.randint(0,order,n_symbols)
elif same_pkt == 1:
st = np.random.get_state()
np.random.seed(5)
# Omitted for speed
#itr = (np.random.randint(0,order) for x in range(n_symbols))
#symbs = np.fromiter(itr,dtype='int', count = n_symbols)
symbs=np.random.randint(0,order,n_symbols)
np.random.set_state(st)
#print(symbs)
s=const[symbs]
mod=upfirdn(h, s,sps).astype('complex64')
return mod[skp:-skp].astype('complex64')
def modulateData(self, data):
"""
Modulates the given data for a given frequency center and sampling frequency.
Parameeters
-------------
data : str
data represented as a string
Returns
--------
1-D ndarray of floats
"""
# Get Pulse Shaping Filter
g = self.pulseShapingFilter(self.D, self.alpha, self.P)
_pilots = self.pilot_sequence # alias
# symbol mapping
symbols = self.symbolMap(data, False)
# create packet by concatenating pilots with data
packet = list(_pilots)
packet.extend(symbols)
# upsample packet and convolve packetup with pulse shaping filter g
m = sig.upfirdn(g, packet, self.P)
return m
def modulate(self, bit_sequence: np.ndarray) -> np.ndarray:
"""
GFSK modulate a bit sequence
Returns signal complex QI signal
"""
# Prevent underflow in case of a bit_sequence of unsigned int (2*0-1 =
# underflow).
bit_sequence_signed = bit_sequence.astype(int)
# upsample the bit_sequence, and make et NRZ (i.e. {0,1}-> {-1,1})
c_t = upfirdn(h=[1] * self.L, x=2 * bit_sequence_signed - 1, up=self.L)
h_t = self.gaussianLPF()
# convolve the gaussian filter with the NRZ sequence
b_t = np.convolve(h_t, c_t, 'full')
# normalize the b_t sequence to be between -1 and 1
bnorm_t = b_t / np.abs(b_t).max()
# Integrate over the output of the gaussian filter to get phase information
# using lfilter makes a low pass filter, corresponding to integrating
phi_t = lfilter(b=[1], a=[1, -1],
x=bnorm_t * self.Ts) * self.h * np.pi / self.Tb
# calculate inphase and quadrature for baseband signal
I = np.cos(phi_t)
Q = np.sin(phi_t)
# make complex baseband signal
s_bb = I - 1j * Q
return s_bb
def upsample(x, n, axis=0, trim=False):
x = np.atleast_1d(x)
x = signal.upfirdn([1], x, n, axis=axis)
pads = np.zeros((x.ndim, 2), dtype=int)
pads[axis, 1] = n - 1
y = x if trim else np.pad(x, pads)
return y
def get_annot_activation(times, freqs, mtrack_duration):
n_time_frames = int(np.ceil(mtrack_duration * float(44100)))
time_grid = librosa.core.frames_to_time(range(n_time_frames),
sr=44100,
hop_length=1)
time_bins = grid_to_bins(time_grid, 0.0, time_grid[-1])
annot_time_idx = np.digitize(times, time_bins) - 1
good_indices = annot_time_idx < len(time_grid)
annot_time_idx = annot_time_idx[good_indices]
# print(time_grid.shape)
# print(good_indices.shape)
# print(annot_time_idx.shape)
freq_complete = np.zeros(time_grid.shape)
freq_complete[annot_time_idx] = freqs[good_indices]
annot_activation = np.array(freq_complete > 0, dtype=float)
annot_activation = upfirdn(np.ones((256, )), annot_activation)
# blur the edges
temp = np.zeros(annot_activation.shape)
temp += annot_activation
for i in [1, 4, 8, 16, 32, 64, 128]:
temp[256 * i:] += annot_activation[:-(256 * i)]
temp[:-(256 * i)] += annot_activation[256 * i:]
annot_activation = np.array(temp > 0, dtype=float)
annot_activation = np.convolve(annot_activation,
np.ones((2048, )) / 2048.0,
mode='same')
return annot_activation
def convolve_input(self, tx_value, rx_value, filename):
fs, data = wavfile.read(filename)
self.h = upfirdn([1], self.h, 10)
other = resample(self.h, fs)
length = len(data)
plt.figure()
plt.plot(data)
plt.title(f"Input speech, fs={fs}")
plt.ylabel('Amplitude')
plt.xlabel('Time index')
print(data.dtype)
output = np.convolve(other, data)
plt.figure()
plt.plot(output[0:length])
plt.title(
f"Tx:{tx_value}, Rx:{rx_value}, Convolved, max_order = {self.max_order}, fs = {fs}"
)
plt.ylabel('Amplitude')
plt.xlabel('Time index')
folder_str = "output_speeches/"
tx_str = str(tx_value).replace(".", "_")
rx_str = str(rx_value).replace(".", "_")
out_filename = folder_str + tx_str + rx_str + "_output.wav"
wavfile.write(out_filename, fs, output.astype('int16'))
return output
def test_singleton(self, len_h, len_x):
# gh-9844: lengths producing expected outputs
h = np.zeros(len_h)
h[len_h // 2] = 1. # make h a delta
x = np.ones(len_x)
y = upfirdn(h, x, 1, 1)
want = np.pad(x, (len_h // 2, (len_h - 1) // 2), 'constant')
assert_allclose(y, want)
def cell2sparse(Xcq, octaves, bins, firstcenter, atomHOP, atomNr):
'''
%Generates a sparse matrix containing the CQT coefficients (rasterized).
%
%The sparse matrix representation of the CQT coefficients contains all
%computed coefficients at the corresponding time-frequency location
%(similar to a spectrogram). For lower frequencies this means, that
%each coefficient is followed by zeros stemming from the fact, that the time
%resolution for lower frequencies decreases as the frequency resolution
%increases. Due to the design of the CQT kernel, however, the coefficients
%of different octaves are synchronised, meaning that for the second highest
%octave each coefficient is followed by one zero, for the next octave down
%two zeros are inserted, for the next octave four zeros are inserted and so
%on.
%
%INPUT:
% Xcq ... Dict array consisting of all coefficients for all octaves
% octaves ... Number of octaves processed
% bins ... Number of bins per octave
% firstcenter ... Location of the leftmost atom-stack in the temporal
% kernel
% atomHOP ... Spacing of two consecutive atom stacks
% atomNr ... Number of atoms per bin within the kernel
%
%%He Wang, 2020/12/01 [email protected]
'''
# this version uses less memory but is noticable slower
emptyHops = firstcenter/atomHOP
drops = emptyHops*np.power(2, octaves - np.arange(1, octaves + 1)) - emptyHops
Len = int(np.max((np.asarray([atomNr*c.shape[1] for _,c in Xcq.items()]) - drops) * np.power(2, np.arange(octaves)))) # number of columns of output matrix
spCQT = np.empty((0,Len)).astype(np.complex)
for i in range(1, octaves+1)[::-1]:
drop = int(emptyHops*2**(octaves-i)-emptyHops) # first coefficients of all octaves have to be in synchrony
X = Xcq[i]
if atomNr > 1: # more than one atom per bin --> reshape
Xoct = np.zeros((bins, atomNr*X.shape[1] - drop)).astype(np.complex)
for u in range(bins): # reshape to continous windows for each bin (for the case of several wins per frame)
octX_bin = X[u*atomNr:(u+1)*atomNr,:]
Xcont = octX_bin.T.reshape(-1)
Xoct[u,:] = Xcont[drop:]
X = Xoct
else:
X = X[:,drop:]
X = np.pad(upfirdn([1], X.T, 2**(i-1), axis=0), [[0,2**(i-1)-1],[0,0]], mode='constant').T # upfirdn: upsampling with zeros insertion
X = np.append(X, np.zeros((bins, Len-X.shape[1])), axis=1)
spCQT = np.append(spCQT, X, axis=0)
return spCQT
def writeInterpolateTests(config, startNb, format):
#interpolate=[2,4,8]
#blocks=[1,2,4,8,16]
#numTaps =[1,2,4,8,16]
interpolate = [1, 2, 4, 5, 8, 9]
blocks = [
Tools.loopnb(format, Tools.TAILONLY),
Tools.loopnb(format, Tools.BODYONLY),
Tools.loopnb(format, Tools.BODYANDTAIL),
]
numTapsFactor = [4, 8]
ref = []
allConfigs = cartesian(interpolate, blocks, numTapsFactor)
allsamples = []
allcoefs = []
alloutput = []
for (q, blockSize, numTapsF) in allConfigs:
# numTaps must be a multiple of q
numTaps = numTapsF * q
b = np.array(list(range(1, numTaps + 1))) / (3.0 * (numTaps + 2))
nbsamples = blockSize
samples = np.random.randn(nbsamples)
samples = Tools.normalize(samples)
#output=scipy.signal.decimate(samples,q,ftype=scipy.signal.dlti(b,1.0),zero_phase=False)
output = upfirdn(b,
samples,
up=q,
down=1,
axis=-1,
mode='constant',
cval=0)
output = output[0:blockSize * q]
#print(debug-output)
allsamples += list(samples)
alloutput += list(output)
allcoefs += list(reversed(b))
ref += [q, len(b), len(samples), len(output)]
config.writeInput(startNb, allsamples)
config.writeInput(startNb, allcoefs, "Coefs")
config.writeReference(startNb, alloutput)
config.writeInputU32(startNb, ref, "Configs")
startNb = startNb + 1
return (startNb)
def prop(self, signal: Signal):
from scipy.signal import upfirdn
signal.data_sample = upfirdn(self.h, signal.symbol, signal.sps, 1)
signal.data_sample = roll(signal.data_sample, int(-self.span / 2 * self.sps), axis=-1)
tempx = signal.data_sample[0, 0:signal.sps * signal.data_len]
tempy = signal.data_sample[1, 0:signal.sps * signal.data_len]
signal.data_sample = np.array([tempx, tempy])
def test_modes(self, size, h_len, mode, dtype):
random_state = np.random.RandomState(5)
x = random_state.randn(size).astype(dtype)
if dtype in (np.complex64, np.complex128):
x += 1j * random_state.randn(size)
h = np.arange(1, 1 + h_len, dtype=x.real.dtype)
y = upfirdn(h, x, up=1, down=1, mode=mode)
# expected result: pad the input, filter with zero padding, then crop
npad = h_len - 1
if mode in ['antisymmetric', 'antireflect', 'smooth', 'line']:
# use _pad_test test function for modes not supported by np.pad.
xpad = _pad_test(x, npre=npad, npost=npad, mode=mode)
else:
xpad = np.pad(x, npad, mode=mode)
ypad = upfirdn(h, xpad, up=1, down=1, mode='constant')
y_expected = ypad[npad:-npad]
assert_allclose(y, y_expected, atol=1e-6, rtol=1e-6)
def test_upfirdn2d(self, rand_2d_data_gen, num_samps, up, down, use_numba):
cpu_sig, gpu_sig = rand_2d_data_gen(num_samps)
h = [1, 1, 1]
cpu_resample = signal.upfirdn(h, cpu_sig, up, down)
gpu_resample = cp.asnumpy(
cusignal.upfirdn(h, gpu_sig, up, down, use_numba=use_numba))
assert array_equal(cpu_resample, gpu_resample)
def ex2_6_interpolate(signal=None,
ts=None,
up_factor=2,
down_factor=11,
sampling_frequency=sf,
ftype='fir',
show=False):
if signal is None and ts is None:
ts, signal = ex2_1_generate_sinusoid()
sampling_frequency = sf
if signal is not None and ts is None:
ts = np.linspace(0, len(signal) / sf, len(signal), endpoint=False)
# just do the beginning (bc of time complexity)
ts, signal = ts[:5000], signal[:5000]
if ftype == 'fir':
nyq_rate = sampling_frequency / 2
width = 400.0 / nyq_rate # with a 400 Hz transition width
ripple_db = 60.0 # attenuation in the stop band (dB)
filter_order, beta = kaiserord(
ripple_db, width) # order and Kaiser parameter for the FIR filter
cutoff = 0.5 / up_factor
filter_taps = firwin(filter_order,
cutoff * nyq_rate,
window=('kaiser', beta),
fs=sampling_frequency)
print("Filter order", filter_order)
resampled_signal = upfirdn(filter_taps,
signal,
up=up_factor,
down=down_factor)
if ftype == 'cheby2':
pass
# TODO: with Chebychev II filter
sampling_frequency *= up_factor / down_factor
resampled_ts = np.linspace(0,
len(resampled_signal) / sampling_frequency,
len(resampled_signal),
endpoint=False)
plt.plot_signal_processed(ts,
signal,
resampled_ts,
resampled_signal,
'Interpolated',
'Interpolated with factor ' + str(up_factor) +
'/' + str(down_factor),
show=show,
xlim=xlim)
return resampled_ts, resampled_signal
def interp(arr, factor): #linear interpolation by factor
#For the correct FIR coefficents of a Linear Interpolation method, harr is going to hold such coefficents
harr=[]#we create an arry as to be the input of FIR at the upfirdn function, used from scipy
harr.extend(np.linspace(1,factor-1,factor-1)) #we use extend as to iterate over the array generated and keep it in a single dimension
harr.append(factor)#for signal dimension 'extension' we simply use append function
harr.extend((np.linspace(factor-1,1,factor-1))) #inside the extend brackets one could also use: np.flip(np.linspace(1,factor-1,factor-1))
harr=np.divide(harr,factor)
return signal.upfirdn(harr, arr, factor)[:-factor]
def upsample(self, x, upsampling_rate):
self.sampling_frequency *= upsampling_rate
self.nyquist_frequency *= upsampling_rate
filterlen = 101
b = firwin(101, 1.0 / upsampling_rate)
y = upfirdn(b, x, up=upsampling_rate)
y = [i * upsampling_rate for i in y]
y = y[filterlen / 2:len(y) - filterlen / 2]
return y
def shape_symbols(h, p_data_p_symbols):
"""
Use the pulse h to shape the p_data_p_symbols given, and up-sample by USF before
:param h: The pulse to use to do the pulse shaping
:param p_data_p_symbols: The preamble-data-preamble symbols to shape
:return: The preamble-data-preamble sample resulting from the pulse shaping
"""
if params.logs:
print("Pulse shaping the symbols...")
if params.MOD == 1 or params.MOD == 2:
p_data_p_samples = upfirdn(h, p_data_p_symbols, params.USF)
if params.logs:
print("Samples: {}\n{}".format(np.shape(p_data_p_samples),
p_data_p_samples))
print("Up-sampling factor: {}".format(params.USF))
if params.plots:
plot_helper.samples_fft_plots(p_data_p_samples,
"Samples after the pulse shaping",
shift=True)
elif params.MOD == 3:
p_data_p_samples = []
for i in range(len(p_data_p_symbols)):
p_data_p_samples.append(upfirdn(h, p_data_p_symbols[i],
params.USF))
if params.plots:
for i in range(len(p_data_p_samples)):
plot_helper.samples_fft_plots(
p_data_p_samples[i],
"Samples {} after the pulse shaping".format(i),
shift=True)
else:
raise ValueError("This mapping type does not exist yet... He he he")
if params.logs:
print("--------------------------------------------------------")
return p_data_p_samples
def pf_run(self, sig_array, pf_bank, rate=1):
"""
Runs the input array through the polyphase filter bank.
"""
fil_out = []
offset = self.paths / self.rate
for j in range(rate):
for i, input_vec in enumerate(sig_array):
# remember in channelizer samples are fed to last path first -- it is a decimating filter.
index = i + j * offset
fil_out.append(
signal.upfirdn(pf_bank[index, :], sig_array[i, :]))
return np.asarray(fil_out)
def scrub(self, x, axis=-1):
yr = np.apply_along_axis(upfirdn_naive, axis, x, self.h, self.up,
self.down)
y = upfirdn(self.h, x, self.up, self.down, axis=axis)
dtypes = (self.h.dtype, x.dtype)
if all(d == np.complex64 for d in dtypes):
assert_equal(y.dtype, np.complex64)
elif np.complex64 in dtypes and np.float32 in dtypes:
assert_equal(y.dtype, np.complex64)
elif all(d == np.float32 for d in dtypes):
assert_equal(y.dtype, np.float32)
elif np.complex128 in dtypes or np.complex64 in dtypes:
assert_equal(y.dtype, np.complex128)
else:
assert_equal(y.dtype, np.float64)
assert_allclose(yr, y)
def scrub(self, x, axis=-1):
yr = np.apply_along_axis(upfirdn_naive, axis, x,
self.h, self.up, self.down)
y = upfirdn(self.h, x, self.up, self.down, axis=axis)
dtypes = (self.h.dtype, x.dtype)
if all(d == np.complex64 for d in dtypes):
assert_equal(y.dtype, np.complex64)
elif np.complex64 in dtypes and np.float32 in dtypes:
assert_equal(y.dtype, np.complex64)
elif all(d == np.float32 for d in dtypes):
assert_equal(y.dtype, np.float32)
elif np.complex128 in dtypes or np.complex64 in dtypes:
assert_equal(y.dtype, np.complex128)
else:
assert_equal(y.dtype, np.float64)
assert_allclose(yr, y)
def test_vs_lfilter(self):
# Check that up=1.0 gives same answer as lfilter + slicing
random_state = np.random.RandomState(17)
try_types = (int, np.float32, np.complex64, float, complex)
size = 10000
down_factors = [2, 11, 79]
for dtype in try_types:
x = random_state.randn(size).astype(dtype)
if dtype in (np.complex64, np.complex128):
x += 1j * random_state.randn(size)
for down in down_factors:
h = firwin(31, 1. / down, window='hamming')
yl = lfilter(h, 1.0, x)[::down]
y = upfirdn(h, x, up=1, down=down)
assert_allclose(yl, y[:yl.size], atol=1e-7, rtol=1e-7)
def test_vs_convolve(self, down, want_len):
# Check that up=1.0 gives same answer as convolve + slicing
random_state = np.random.RandomState(17)
try_types = (int, np.float32, np.complex64, float, complex)
size = 10000
for dtype in try_types:
x = random_state.randn(size).astype(dtype)
if dtype in (np.complex64, np.complex128):
x += 1j * random_state.randn(size)
h = firwin(31, 1. / down, window='hamming')
yl = upfirdn_naive(x, h, 1, down)
y = upfirdn(h, x, up=1, down=down)
assert y.shape == (want_len, )
assert yl.shape[0] == y.shape[0]
assert_allclose(yl, y, atol=1e-7, rtol=1e-7)
def test_vs_lfilter(self):
# Check that up=1.0 gives same answer as lfilter + slicing
random_state = np.random.RandomState(17)
try_types = (int, np.float32, np.complex64, float, complex)
size = 10000
down_factors = [2, 11, 79]
for dtype in try_types:
x = random_state.randn(size).astype(dtype)
if dtype in (np.complex64, np.complex128):
x += 1j * random_state.randn(size)
for down in down_factors:
h = firwin(31, 1. / down, window='hamming')
yl = lfilter(h, 1.0, x)[::down]
y = upfirdn(h, x, up=1, down=down)
assert_allclose(yl, y[:yl.size], atol=1e-7, rtol=1e-7)
def downconvert(x, sps, fc, fs=2.0, g=None):
"""Downconvert a passband signal with a matched pulse shaping filter.
This function supports downconversion by an integer factor. For a more general
baseband conversion (but without matched filtering), see :func:`arlpy.signal.pb2bb`.
If the carrier frequency is 0, the input is assumed to be complex baseband, and only
undergoes matched filtering and downsampling. If the pulse shape is None, a
rectangular pulse shape is assumed.
The downconversion process introduces a group delay depending on the matched
filter. It is usually (len(g)-1)/2 passband samples.
:param x: real passband data (or complex baseband data at passband sampling rate, if fc=0)
:param sps: number of passband samples per baseband symbol
:param fc: carrier frequency in Hz
:param fs: passband sampling rate
:param g: pulse shaping filter (for matched filtering)
>>> import arlpy
>>> d1 = arlpy.comms.random_data(100, 4)
>>> qpsk = arlpy.comms.psk(4)
>>> bb1 = arlpy.comms.modulate(d1, qpsk)
>>> rrc = arlpy.comms.rrcosfir(0.25, 6)
>>> pb = arlpy.comms.upconvert(bb1, 6, 27000, 108000, rrc)
>>> bb2 = arlpy.comms.downconvert(pb, 6, 27000, 108000, rrc)
>>> delay = (len(rrc)-1)/2 # compute passband group delay of rrc FIR filter
>>> delay = 2*delay/6 # compute baseband group delay after filtering twice
>>> d2 = arlpy.comms.demodulate(bb2[delay:-delay], qpsk)
>>> arlpy.comms.ser(d1, d2)
0.0
"""
if fc == 0:
y = _np.asarray(x, dtype=_np.complex)
else:
y = _sp.hilbert(x) / 2
y *= _sqrt(2) * _np.exp(-2j * _pi * fc * _time(y, fs))
if g is None:
y = _np.sum(_np.reshape(y,
(sps, -1), order='F'), axis=0) / _np.sqrt(sps)
else:
y = _sp.upfirdn(g, y, down=sps)
return y
def dtmfcut(xx, fs):
"""DTMFCUT find the DTMF tones within x[n]
usage:
indx = dtmfmain(xx,fs)
length of nstart = M = number of tones found
nstart is the set of STARTING indices
nstop is the set of ENDING indices
xx = input signal vector
fs = sampling frequency
Looks for silence regions which must at least 10 millisecs long.
Also the tones must be longer than 100 msec
"""
xx = np.asarray(xx)
xx = (xx / max(np.abs(xx))) # normalize xx
Lx = len(xx)
if (0.01 * fs) == 0.5:
Lz = 1
else:
Lz = round(0.01*fs)
setpoint = 0.02 # make everything below 2% zero
xx = upfirdn(np.ones(Lz)/ Lz, np.abs(xx))
xx = np.diff(((xx > setpoint) * 1))
jkl = np.asarray(np.where(xx != 0))
if xx[jkl.take(0)] < 0:
jkl = np.insert(jkl, 0, 1)
if x[jkl.take(-1)] > 0:
jkl = np.append(jkl, Lx-1)
indx = np.array([-1, -1]).reshape(2,1)
while len(jkl) > 1:
if jkl[1] > (jkl[0] + 10 * Lz):
indx = np.append(indx, np.vstack((jkl[[0, 1]])), axis=1)
jkl = np.delete(jkl, [0, 1])
nstart = indx[0,1:]
nstop = indx[1,1:]
return nstart, nstop
def scrub(self, x, axis=-1):
yr = np.apply_along_axis(upfirdn_naive, axis, x, self.h, self.up,
self.down)
want_len = _output_len(len(self.h), x.shape[axis], self.up, self.down)
assert yr.shape[axis] == want_len
y = upfirdn(self.h, x, self.up, self.down, axis=axis)
assert y.shape[axis] == want_len
assert y.shape == yr.shape
dtypes = (self.h.dtype, x.dtype)
if all(d == np.complex64 for d in dtypes):
assert_equal(y.dtype, np.complex64)
elif np.complex64 in dtypes and np.float32 in dtypes:
assert_equal(y.dtype, np.complex64)
elif all(d == np.float32 for d in dtypes):
assert_equal(y.dtype, np.float32)
elif np.complex128 in dtypes or np.complex64 in dtypes:
assert_equal(y.dtype, np.complex128)
else:
assert_equal(y.dtype, np.float64)
assert_allclose(yr, y)
def resample_matlab_like(x_orig,p,q):
if len(x_orig.shape)>2:
raise ValueError('x must be a vector or 2d matrix')
if x_orig.shape[0]<x_orig.shape[1]:
x=x_orig.T
else:
x= x_orig
beta = 5
N = 10
frac=Fraction(p, q)
p = frac.numerator
q = frac.denominator
pqmax = max(p,q)
fc = 1/2/pqmax
L = 2*N*pqmax + 1
h = firls( L, np.array([0,2*fc,2*fc,1]), np.array([1,1,0,0]))*kaiser(L,beta)
h = p*h/sum(h)
Lhalf = (L-1)/2
Lx = x.shape[0]
nz = int(np.floor(q-np.mod(Lhalf,q)))
z = np.zeros((nz,))
h = np.concatenate((z,h))
Lhalf = Lhalf + nz
delay = int(np.floor(np.ceil(Lhalf)/q))
nz1 = 0
while np.ceil( ((Lx-1)*p+len(h)+nz1 )/q ) - delay < np.ceil(Lx*p/q):
nz1 = nz1+1
h = np.concatenate((h,np.zeros(nz1,)))
y = upfirdn(h,x,p,q,axis=0)
Ly = int(np.ceil(Lx*p/q))
y = y[delay:]
y = y[:Ly]
if x_orig.shape[0]<x_orig.shape[1]:
y=y.T
return y
def time_upfirdn2d(self, up, down, axis):
for h, x in self.pairs:
signal.upfirdn(h, x, up=up, down=down, axis=axis)
def time_upfirdn1d(self, up, down):
for h, x in self.pairs:
signal.upfirdn(h, x, up=up, down=down)
