pfb.py

#!/usr/bin/env python
#
# Copyright 2009,2010,2012 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
#


import math

from gnuradio import gr, fft, blocks

from . import optfir
from . import filter_python as filter, fft


class channelizer_ccf(gr.hier_block2):
    '''
    Make a Polyphase Filter channelizer (complex in, complex out, floating-point taps)

    This simplifies the interface by allowing a single input stream to connect to this block.
    It will then output a stream for each channel.
    '''

    def __init__(self, numchans, taps=None, oversample_rate=1, atten=100):
        gr.hier_block2.__init__(self, "pfb_channelizer_ccf",
                                gr.io_signature(1, 1, gr.sizeof_gr_complex),
                                gr.io_signature(numchans, numchans, gr.sizeof_gr_complex))

        self._nchans = numchans
        self._oversample_rate = oversample_rate

        if (taps is not None) and (len(taps) > 0):
            self._taps = taps
        else:
            self._taps = self.create_taps(self._nchans, atten)

        self.s2ss = blocks.stream_to_streams(
            gr.sizeof_gr_complex, self._nchans)
        self.pfb = filter.pfb_channelizer_ccf(self._nchans, self._taps,
                                              self._oversample_rate)
        self.connect(self, self.s2ss)

        for i in range(self._nchans):
            self.connect((self.s2ss, i), (self.pfb, i))
            self.connect((self.pfb, i), (self, i))

    def set_channel_map(self, newmap):
        self.pfb.set_channel_map(newmap)

    def set_taps(self, taps):
        self.pfb.set_taps(taps)

    def taps(self):
        return self.pfb.taps()

    def declare_sample_delay(self, delay):
        self.pfb.declare_sample_delay(delay)

    @staticmethod
    def create_taps(numchans, atten=100):
        # Create a filter that covers the full bandwidth of the input signal
        bw = 0.4
        tb = 0.2
        ripple = 0.1
        while True:
            try:
                taps = optfir.low_pass(1, numchans, bw, bw + tb, ripple, atten)
                return tap
            except ValueError as e:
                # This shouldn't happen, unless numchans is strange
                raise RuntimeError("couldn't design filter; this probably constitutes a bug")
            except RuntimeError:
                ripple += 0.01
                print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))

                # Build in an exit strategy; if we've come this far, it ain't working.
                if(ripple >= 1.0):
                    raise RuntimeError(
                        "optfir could not generate an appropriate filter.")


class interpolator_ccf(gr.hier_block2):
    '''
    Make a Polyphase Filter interpolator (complex in, complex out, floating-point taps)

    The block takes a single complex stream in and outputs a single complex
    stream out. As such, it requires no extra glue to handle the input/output
    streams. This block is provided to be consistent with the interface to the
    other PFB block.
    '''

    def __init__(self, interp, taps=None, atten=100):
        gr.hier_block2.__init__(self, "pfb_interpolator_ccf",
                                gr.io_signature(1, 1, gr.sizeof_gr_complex),
                                gr.io_signature(1, 1, gr.sizeof_gr_complex))

        self._interp = interp
        self._taps = taps

        if (taps is not None) and (len(taps) > 0):
            self._taps = taps
        else:
            self._taps = self.create_taps(self._interp, atten)

        self.pfb = filter.pfb_interpolator_ccf(self._interp, self._taps)

        self.connect(self, self.pfb)
        self.connect(self.pfb, self)

    def set_taps(self, taps):
        self.pfb.set_taps(taps)

    def declare_sample_delay(self, delay):
        self.pfb.declare_sample_delay(delay)

    @staticmethod
    def create_taps(interp, atten):
        # Create a filter that covers the full bandwidth of the input signal
        bw = 0.4
        tb = 0.2
        ripple = 0.99
        while True:
            try:
                taps = optfir.low_pass(
                    interp, interp, bw, bw + tb, ripple, atten)
                return taps
            except RuntimeError:
                ripple += 0.01
                print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))

                # Build in an exit strategy; if we've come this far, it ain't working.
                if(ripple >= 1.0):
                    raise RuntimeError(
                        "optfir could not generate an appropriate filter.")
            # We bubble up ValueError – probably caused by user input


class decimator_ccf(gr.hier_block2):
    '''
    Make a Polyphase Filter decimator (complex in, complex out, floating-point taps)

    This simplifies the interface by allowing a single input stream to connect to this block.
    It will then output a stream that is the decimated output stream.
    '''

    def __init__(self, decim, taps=None, channel=0, atten=100,
                 use_fft_rotators=True, use_fft_filters=True):
        gr.hier_block2.__init__(self, "pfb_decimator_ccf",
                                gr.io_signature(1, 1, gr.sizeof_gr_complex),
                                gr.io_signature(1, 1, gr.sizeof_gr_complex))

        self._decim = decim
        self._channel = channel

        if (taps is not None) and (len(taps) > 0):
            self._taps = taps
        else:
            self._taps = self.create_taps(self._decim, atten)

        self.s2ss = blocks.stream_to_streams(gr.sizeof_gr_complex, self._decim)
        self.pfb = filter.pfb_decimator_ccf(self._decim, self._taps, self._channel,
                                            use_fft_rotators, use_fft_filters)

        self.connect(self, self.s2ss)

        for i in range(self._decim):
            self.connect((self.s2ss, i), (self.pfb, i))

        self.connect(self.pfb, self)

    def set_taps(self, taps):
        self.pfb.set_taps(taps)

    def set_channel(self, chan):
        self.pfb.set_channel(chan)

    def declare_sample_delay(self, delay):
        self.pfb.declare_sample_delay(delay)

    @staticmethod
    def create_taps(decim, atten=100):
        # Create a filter that covers the full bandwidth of the input signal
        bw = 0.4
        tb = 0.2
        ripple = 0.1
        while True:
            try:
                taps = optfir.low_pass(1, decim, bw, bw + tb, ripple, atten)
                return taps
            except RuntimeError:
                ripple += 0.01
                print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))

                # Build in an exit strategy; if we've come this far, it ain't working.
                if(ripple >= 1.0):
                    raise RuntimeError(
                        "optfir could not generate an appropriate filter.")
            # Not handling ValueError – probably a user input caused this.


class arb_resampler_ccf(gr.hier_block2):
    '''
    Convenience wrapper for the polyphase filterbank arbitrary resampler.

    The block takes a single complex stream in and outputs a single complex
    stream out. As such, it requires no extra glue to handle the input/output
    streams. This block is provided to be consistent with the interface to the
    other PFB block.
    '''

    def __init__(self, rate, taps=None, flt_size=32, atten=100):
        gr.hier_block2.__init__(self, "pfb_arb_resampler_ccf",
                                # Input signature
                                gr.io_signature(1, 1, gr.sizeof_gr_complex),
                                gr.io_signature(1, 1, gr.sizeof_gr_complex))  # Output signature

        self._rate = rate
        self._size = flt_size

        if (taps is not None) and (len(taps) > 0):
            self._taps = taps
        else:
            self._taps = self.create_taps(self._rate, self._size, atten)

        self.pfb = filter.pfb_arb_resampler_ccf(
            self._rate, self._taps, self._size)
        #print("PFB has %d taps\n" % (len(self._taps),))

        self.connect(self, self.pfb)
        self.connect(self.pfb, self)

    # Note -- set_taps not implemented in base class yet
    def set_taps(self, taps):
        self.pfb.set_taps(taps)

    def set_rate(self, rate):
        self.pfb.set_rate(rate)

    def declare_sample_delay(self, delay):
        self.pfb.declare_sample_delay(delay)

    @staticmethod
    def create_taps(rate, flt_size=32, atten=100):
        # Create a filter that covers the full bandwidth of the output signal

        # If rate >= 1, we need to prevent images in the output,
        # so we have to filter it to less than half the channel
        # width of 0.5.  If rate < 1, we need to filter to less
        # than half the output signal's bw to avoid aliasing, so
        # the half-band here is 0.5*rate.
        percent = 0.80
        if(rate < 1):
            halfband = 0.5 * rate
            bw = percent * halfband
            tb = (percent / 2.0) * halfband
            ripple = 0.1

            # As we drop the bw factor, the optfir filter has a harder time converging;
            # using the firdes method here for better results.
            return filter.firdes.low_pass_2(flt_size, flt_size, bw, tb, atten,
                                            fft.window.WIN_BLACKMAN_HARRIS)
        else:
            halfband = 0.5
            bw = percent * halfband
            tb = (percent / 2.0) * halfband
            ripple = 0.1
            taps = None

            while True:
                try:
                    taps = optfir.low_pass(
                        flt_size, flt_size, bw, bw + tb, ripple, atten)
                    return taps
                except RuntimeError:
                    ripple += 0.01
                    print(
                        "Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))

                    # Build in an exit strategy; if we've come this far, it ain't working.
                    if(ripple >= 1.0):
                        raise RuntimeError(
                            "optfir could not generate an appropriate filter.")
                # We intentionally don't handle ValueError here, because it's most likely caused by user input


class arb_resampler_fff(gr.hier_block2):
    '''
    Convenience wrapper for the polyphase filterbank arbitrary resampler.

    The block takes a single float stream in and outputs a single float
    stream out. As such, it requires no extra glue to handle the input/output
    streams. This block is provided to be consistent with the interface to the
    other PFB block.
    '''

    def __init__(self, rate, taps=None, flt_size=32, atten=100):
        gr.hier_block2.__init__(self, "pfb_arb_resampler_fff",
                                # Input signature
                                gr.io_signature(1, 1, gr.sizeof_float),
                                gr.io_signature(1, 1, gr.sizeof_float))  # Output signature

        self._rate = rate
        self._size = flt_size

        if (taps is not None) and (len(taps) > 0):
            self._taps = taps
        else:
            self._taps = self.create_taps(self._rate, self._size, atten)

        self.pfb = filter.pfb_arb_resampler_fff(
            self._rate, self._taps, self._size)
        # print "PFB has %d taps\n" % (len(self._taps),)

        self.connect(self, self.pfb)
        self.connect(self.pfb, self)

    # Note -- set_taps not implemented in base class yet
    def set_taps(self, taps):
        self.pfb.set_taps(taps)

    def set_rate(self, rate):
        self.pfb.set_rate(rate)

    def declare_sample_delay(self, delay):
        self.pfb.declare_sample_delay(delay)

    @staticmethod
    def create_taps(rate, flt_size=32, atten=100):
        # Create a filter that covers the full bandwidth of the input signal

        # If rate >= 1, we need to prevent images in the output,
        # so we have to filter it to less than half the channel
        # width of 0.5.  If rate < 1, we need to filter to less
        # than half the output signal's bw to avoid aliasing, so
        # the half-band here is 0.5*rate.
        percent = 0.80
        if(rate < 1):
            halfband = 0.5 * rate
            bw = percent * halfband
            tb = (percent / 2.0) * halfband
            ripple = 0.1

            # As we drop the bw factor, the optfir filter has a harder time converging;
            # using the firdes method here for better results.
            return filter.firdes.low_pass_2(flt_size, flt_size, bw, tb, atten,
                                            fft.window.WIN_BLACKMAN_HARRIS)
        else:
            halfband = 0.5
            bw = percent * halfband
            tb = (percent / 2.0) * halfband
            ripple = 0.1

            while True:
                try:
                    taps = optfir.low_pass(
                        flt_size, flt_size, bw, bw + tb, ripple, atten)
                    return taps
                except RuntimeError:
                    ripple += 0.01
                    print(
                        "Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))

                    # Build in an exit strategy; if we've come this far, it ain't working.
                    if(ripple >= 1.0):
                        raise RuntimeError(
                            "optfir could not generate an appropriate filter.")
                # If a ValueError happens here, it's probably due to specific user input


class arb_resampler_ccc(gr.hier_block2):
    '''
    Convenience wrapper for the polyphase filterbank arbitrary resampler.

    The block takes a single complex stream in and outputs a single complex
    stream out. As such, it requires no extra glue to handle the input/output
    streams. This block is provided to be consistent with the interface to the
    other PFB block.
    '''

    def __init__(self, rate, taps=None, flt_size=32, atten=100):
        gr.hier_block2.__init__(self, "pfb_arb_resampler_ccc",
                                # Input signature
                                gr.io_signature(1, 1, gr.sizeof_gr_complex),
                                gr.io_signature(1, 1, gr.sizeof_gr_complex))  # Output signature

        self._rate = rate
        self._size = flt_size

        if (taps is not None) and (len(taps) > 0):
            self._taps = taps
        else:
            self._taps = self.create_taps(self._rate, self._size, atten)

        self.pfb = filter.pfb_arb_resampler_ccc(
            self._rate, self._taps, self._size)
        # print "PFB has %d taps\n" % (len(self._taps),)

        self.connect(self, self.pfb)
        self.connect(self.pfb, self)

    # Note -- set_taps not implemented in base class yet
    def set_taps(self, taps):
        self.pfb.set_taps(taps)

    def set_rate(self, rate):
        self.pfb.set_rate(rate)

    def declare_sample_delay(self, delay):
        self.pfb.declare_sample_delay(delay)

    @staticmethod
    def create_taps(rate, flt_size=32, atten=100):
        # Create a filter that covers the full bandwidth of the input signal
        bw = 0.4
        tb = 0.2
        ripple = 0.1
        while True:
            try:
                taps = optfir.low_pass(
                    flt_size, flt_size, bw, bw + tb, ripple, atten)
                return taps
            except RuntimeError:
                ripple += 0.01
                print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))

                # Build in an exit strategy; if we've come this far, it ain't working.
                if(ripple >= 1.0):
                    raise RuntimeError(
                        "optfir could not generate an appropriate filter.")
                # If a ValueError happens here, it's probably due to specific user input


class channelizer_hier_ccf(gr.hier_block2):
    """
    Make a Polyphase Filter channelizer (complex in, complex out, floating-point taps)

    Args:
    n_chans: The number of channels to split into.
    n_filterbanks: The number of filterbank blocks to use (default=2).
    taps: The taps to use.  If this is `None` then taps are generated using optfir.low_pass.
    outchans: Which channels to output streams for (a list of integers) (default is all channels).
    atten: Stop band attenuation.
    bw: The fraction of the channel you want to keep.
    tb: Transition band with as fraction of channel width.
    ripple: Pass band ripple in dB.
    """

    def __init__(self, n_chans, n_filterbanks=1, taps=None, outchans=None,
                 atten=100, bw=1.0, tb=0.2, ripple=0.1):
        if n_filterbanks > n_chans:
            n_filterbanks = n_chans
        if outchans is None:
            outchans = list(range(n_chans))
        gr.hier_block2.__init__(
            self, "pfb_channelizer_hier_ccf",
            gr.io_signature(1, 1, gr.sizeof_gr_complex),
            gr.io_signature(len(outchans), len(outchans), gr.sizeof_gr_complex))
        if taps is None:
            taps = self.create_taps(n_chans, atten, bw, tb, ripple)
        taps = list(taps)
        extra_taps = int(math.ceil(1.0 * len(taps) / n_chans) *
                         n_chans - len(taps))
        taps = taps + [0] * extra_taps
        # Make taps for each channel
        chantaps = [list(reversed(taps[i: len(taps): n_chans]))
                    for i in range(0, n_chans)]
        # Convert the input stream into a stream of vectors.
        self.s2v = blocks.stream_to_vector(gr.sizeof_gr_complex, n_chans)
        # Create a mapping to separate out each filterbank (a group of channels to be processed together)
        # And a list of sets of taps for each filterbank.
        low_cpp = int(n_chans / n_filterbanks)
        extra = n_chans - low_cpp * n_filterbanks
        cpps = [low_cpp + 1] * extra + [low_cpp] * (n_filterbanks - extra)
        splitter_mapping = []
        filterbanktaps = []
        total = 0
        for cpp in cpps:
            splitter_mapping.append([(0, i)
                                    for i in range(total, total + cpp)])
            filterbanktaps.append(chantaps[total: total + cpp])
            total += cpp
        assert(total == n_chans)
        # Split the stream of vectors in n_filterbanks streams of vectors.
        self.splitter = blocks.vector_map(
            gr.sizeof_gr_complex, [n_chans], splitter_mapping)
        # Create the filterbanks
        self.fbs = [filter.filterbank_vcvcf(taps) for taps in filterbanktaps]
        # Combine the streams of vectors back into a single stream of vectors.
        combiner_mapping = [[]]
        for i, cpp in enumerate(cpps):
            for j in range(cpp):
                combiner_mapping[0].append((i, j))
        self.combiner = blocks.vector_map(
            gr.sizeof_gr_complex, cpps, combiner_mapping)
        # Add the final FFT to the channelizer.
        self.fft = fft.fft_vcc(n_chans, forward=True, window=[1.0] * n_chans)
        # Select the desired channels
        if outchans != list(range(n_chans)):
            selector_mapping = [[(0, i) for i in outchans]]
            self.selector = blocks.vector_map(
                gr.sizeof_gr_complex, [n_chans], selector_mapping)
        # Convert stream of vectors to a normal stream.
        self.v2ss = blocks.vector_to_streams(
            gr.sizeof_gr_complex, len(outchans))
        self.connect(self, self.s2v, self.splitter)
        for i in range(0, n_filterbanks):
            self.connect((self.splitter, i), self.fbs[i], (self.combiner, i))
        self.connect(self.combiner, self.fft)
        if outchans != list(range(n_chans)):
            self.connect(self.fft, self.selector, self.v2ss)
        else:
            self.connect(self.fft, self.v2ss)
        for i in range(0, len(outchans)):
            self.connect((self.v2ss, i), (self, i))

    @staticmethod
    def create_taps(n_chans, atten=100, bw=1.0, tb=0.2, ripple=0.1):
        return optfir.low_pass(1, n_chans, bw, bw + tb, ripple, atten)