Create QPKS simulation

The current flow diagram does the following:

  - Generate a QPKS constellation from a random bit source. The
    constellation is parametrized by the 'Constellation Rect. Object'
    and the variables 'sps' (Samples Per Symbol) and 'excess_bw' (Excess
    Bandwidth).

  - Send the modulated signal through a AWGN channel. Noise channel taps
    are controlled with the 'taps' variable, the other paramters are
    given through the 'QT GUI Range' objects.

  - Display the constellation diagram as well as the time and frequency
    domain plots of the signal after the channel (receiver side).

  - Synchronize the clock using a polyphase clock sync with root raised
    cosine filters. The number of filters is stored in 'nfilts' and the
    filter themselves are in 'rcc_taps'.

  - Finally, display the constellation after the RCC filters.

What is still missing:

  - Multipath fading taps in the channel model (for later)

  - Equalization on the receiver side.

    PROBLEM: The wiki tutorial targets GNU Radio 3.9, and uses 'Linear
             Equlizer' and 'Adaptive Algorithm' blocks which are not
             available in GNU Radio 3.8. We need to use 'CMA Equalizer'
             and 'LMS DD Equalizer' and figure out their parameters
             instead. Though this should not be hard.

  - Phase and Fine Frequency Correction.

  - Decode the message.

2 files changed, 1148 insertions, 0 deletions

diff --git a/tests/Simulation/QPKS/qpks.grc b/tests/Simulation/QPKS/qpks.grc
new file mode 100644
index 0000000..b799dc7
--- /dev/null
+++ b/tests/Simulation/QPKS/qpks.grc
@@ -0,0 +1,688 @@
+options:
+  parameters:
+    author: ''
+    category: '[GRC Hier Blocks]'
+    cmake_opt: ''
+    comment: ''
+    copyright: ''
+    description: ''
+    gen_cmake: 'On'
+    gen_linking: dynamic
+    generate_options: qt_gui
+    hier_block_src_path: '.:'
+    id: qpks
+    max_nouts: '0'
+    output_language: python
+    placement: (0,0)
+    qt_qss_theme: ''
+    realtime_scheduling: '1'
+    run: 'True'
+    run_command: '{python} -u {filename}'
+    run_options: prompt
+    sizing_mode: fixed
+    thread_safe_setters: ''
+    title: QPSK
+    window_size: ''
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [8, 8]
+    rotation: 0
+    state: enabled
+
+blocks:
+- name: excess_bw
+  id: variable
+  parameters:
+    comment: ''
+    value: 350e-3
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [320, 140.0]
+    rotation: 0
+    state: true
+- name: freq_offset
+  id: variable_qtgui_range
+  parameters:
+    comment: ''
+    gui_hint: 1,0,1,1
+    label: Frequency Offset
+    min_len: '200'
+    orient: Qt.Horizontal
+    rangeType: float
+    start: -100e-3
+    step: 1e-3
+    stop: 100e-3
+    value: '0'
+    widget: counter_slider
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [648, 340.0]
+    rotation: 0
+    state: true
+- name: nfilts
+  id: variable
+  parameters:
+    comment: ''
+    value: '32'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [920, 540.0]
+    rotation: 0
+    state: true
+- name: noise_volt
+  id: variable_qtgui_range
+  parameters:
+    comment: ''
+    gui_hint: 0,0,1,1
+    label: Noise Voltage
+    min_len: '200'
+    orient: Qt.Horizontal
+    rangeType: float
+    start: '0'
+    step: '0.01'
+    stop: '1'
+    value: '0.0001'
+    widget: counter_slider
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [488, 340.0]
+    rotation: 0
+    state: true
+- name: qpsk_const
+  id: variable_constellation_rect
+  parameters:
+    comment: ''
+    const_points: '[0.707+0.707j, -0.707+0.707j, -0.707-0.707j, 0.707-0.707j]'
+    imag_sect: '2'
+    precision: '8'
+    real_sect: '2'
+    rot_sym: '4'
+    soft_dec_lut: None
+    sym_map: '[0, 1, 3, 2]'
+    w_imag_sect: '1'
+    w_real_sect: '1'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [224, 316.0]
+    rotation: 0
+    state: true
+- name: rrc_taps
+  id: variable
+  parameters:
+    comment: ''
+    value: firdes.root_raised_cosine(nfilts, nfilts, 1.0/float(sps), 0.35, 45*nfilts)
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [992, 540.0]
+    rotation: 0
+    state: true
+- name: samp_rate
+  id: variable
+  parameters:
+    comment: ''
+    value: '32000'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [192, 12.0]
+    rotation: 0
+    state: enabled
+- name: sps
+  id: variable
+  parameters:
+    comment: ''
+    value: '4'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [224, 140.0]
+    rotation: 0
+    state: true
+- name: taps
+  id: variable
+  parameters:
+    comment: ''
+    value: '[1.0 + 0.0j, ]'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [648, 124.0]
+    rotation: 0
+    state: true
+- name: time_offset
+  id: variable_qtgui_range
+  parameters:
+    comment: ''
+    gui_hint: 0,1,1,1
+    label: Timing Offset
+    min_len: '200'
+    orient: Qt.Horizontal
+    rangeType: float
+    start: '0.999'
+    step: '0.0001'
+    stop: '1.001'
+    value: '1.0'
+    widget: counter_slider
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [488, 484.0]
+    rotation: 0
+    state: true
+- name: timing_loop_bw
+  id: variable_qtgui_range
+  parameters:
+    comment: ''
+    gui_hint: 1,1,1,1
+    label: 'Time: BW'
+    min_len: '200'
+    orient: Qt.Horizontal
+    rangeType: float
+    start: '0'
+    step: 10e-3
+    stop: 200e-3
+    value: 2 * 3.141592653589793 / 100
+    widget: counter_slider
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [648, 484.0]
+    rotation: 0
+    state: true
+- name: analog_random_source_x_0
+  id: analog_random_source_x
+  parameters:
+    affinity: ''
+    alias: ''
+    comment: ''
+    max: '2'
+    maxoutbuf: '0'
+    min: '0'
+    minoutbuf: '0'
+    num_samps: '1000'
+    repeat: 'True'
+    type: byte
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [32, 204.0]
+    rotation: 0
+    state: enabled
+- name: blocks_throttle_0
+  id: blocks_throttle
+  parameters:
+    affinity: ''
+    alias: ''
+    comment: ''
+    ignoretag: 'True'
+    maxoutbuf: '0'
+    minoutbuf: '0'
+    samples_per_second: samp_rate
+    type: complex
+    vlen: '1'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [464, 228.0]
+    rotation: 0
+    state: enabled
+- name: channels_channel_model_0
+  id: channels_channel_model
+  parameters:
+    affinity: ''
+    alias: ''
+    block_tags: 'False'
+    comment: ''
+    epsilon: time_offset
+    freq_offset: freq_offset
+    maxoutbuf: '0'
+    minoutbuf: '0'
+    noise_voltage: noise_volt
+    seed: '0'
+    taps: taps
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [648, 188.0]
+    rotation: 0
+    state: enabled
+- name: digital_constellation_modulator_0
+  id: digital_constellation_modulator
+  parameters:
+    affinity: ''
+    alias: ''
+    comment: ''
+    constellation: qpsk_const
+    differential: 'True'
+    excess_bw: excess_bw
+    log: 'False'
+    maxoutbuf: '0'
+    minoutbuf: '0'
+    samples_per_symbol: sps
+    verbose: 'False'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [224, 204.0]
+    rotation: 0
+    state: enabled
+- name: digital_pfb_clock_sync_xxx_0
+  id: digital_pfb_clock_sync_xxx
+  parameters:
+    affinity: ''
+    alias: ''
+    comment: ''
+    filter_size: nfilts
+    init_phase: nfilts/2
+    loop_bw: timing_loop_bw
+    max_dev: '1.5'
+    maxoutbuf: '0'
+    minoutbuf: '0'
+    osps: '1'
+    sps: sps * 1.001
+    taps: rrc_taps
+    type: ccf
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [920, 380.0]
+    rotation: 0
+    state: true
+- name: qtgui_const_sink_x_0
+  id: qtgui_const_sink_x
+  parameters:
+    affinity: ''
+    alias: ''
+    alpha1: '1.0'
+    alpha10: '1.0'
+    alpha2: '1.0'
+    alpha3: '1.0'
+    alpha4: '1.0'
+    alpha5: '1.0'
+    alpha6: '1.0'
+    alpha7: '1.0'
+    alpha8: '1.0'
+    alpha9: '1.0'
+    autoscale: 'False'
+    axislabels: 'True'
+    color1: '"blue"'
+    color10: '"red"'
+    color2: '"red"'
+    color3: '"red"'
+    color4: '"red"'
+    color5: '"red"'
+    color6: '"red"'
+    color7: '"red"'
+    color8: '"red"'
+    color9: '"red"'
+    comment: ''
+    grid: 'False'
+    gui_hint: 2,1,1,1
+    label1: ''
+    label10: ''
+    label2: ''
+    label3: ''
+    label4: ''
+    label5: ''
+    label6: ''
+    label7: ''
+    label8: ''
+    label9: ''
+    legend: 'True'
+    marker1: '0'
+    marker10: '0'
+    marker2: '0'
+    marker3: '0'
+    marker4: '0'
+    marker5: '0'
+    marker6: '0'
+    marker7: '0'
+    marker8: '0'
+    marker9: '0'
+    name: '"After Channel"'
+    nconnections: '1'
+    size: '2048'
+    style1: '0'
+    style10: '0'
+    style2: '0'
+    style3: '0'
+    style4: '0'
+    style5: '0'
+    style6: '0'
+    style7: '0'
+    style8: '0'
+    style9: '0'
+    tr_chan: '0'
+    tr_level: '0.0'
+    tr_mode: qtgui.TRIG_MODE_FREE
+    tr_slope: qtgui.TRIG_SLOPE_POS
+    tr_tag: '""'
+    type: complex
+    update_time: '0.10'
+    width1: '1'
+    width10: '1'
+    width2: '1'
+    width3: '1'
+    width4: '1'
+    width5: '1'
+    width6: '1'
+    width7: '1'
+    width8: '1'
+    width9: '1'
+    xmax: '2'
+    xmin: '-2'
+    ymax: '2'
+    ymin: '-2'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [920, 284.0]
+    rotation: 0
+    state: enabled
+- name: qtgui_const_sink_x_0_0
+  id: qtgui_const_sink_x
+  parameters:
+    affinity: ''
+    alias: ''
+    alpha1: '1.0'
+    alpha10: '1.0'
+    alpha2: '1.0'
+    alpha3: '1.0'
+    alpha4: '1.0'
+    alpha5: '1.0'
+    alpha6: '1.0'
+    alpha7: '1.0'
+    alpha8: '1.0'
+    alpha9: '1.0'
+    autoscale: 'False'
+    axislabels: 'True'
+    color1: '"blue"'
+    color10: '"red"'
+    color2: '"red"'
+    color3: '"red"'
+    color4: '"red"'
+    color5: '"red"'
+    color6: '"red"'
+    color7: '"red"'
+    color8: '"red"'
+    color9: '"red"'
+    comment: ''
+    grid: 'False'
+    gui_hint: 3,1,1,1
+    label1: ''
+    label10: ''
+    label2: ''
+    label3: ''
+    label4: ''
+    label5: ''
+    label6: ''
+    label7: ''
+    label8: ''
+    label9: ''
+    legend: 'True'
+    marker1: '0'
+    marker10: '0'
+    marker2: '0'
+    marker3: '0'
+    marker4: '0'
+    marker5: '0'
+    marker6: '0'
+    marker7: '0'
+    marker8: '0'
+    marker9: '0'
+    name: '"After Clock Sync"'
+    nconnections: '1'
+    size: '2048'
+    style1: '0'
+    style10: '0'
+    style2: '0'
+    style3: '0'
+    style4: '0'
+    style5: '0'
+    style6: '0'
+    style7: '0'
+    style8: '0'
+    style9: '0'
+    tr_chan: '0'
+    tr_level: '0.0'
+    tr_mode: qtgui.TRIG_MODE_FREE
+    tr_slope: qtgui.TRIG_SLOPE_POS
+    tr_tag: '""'
+    type: complex
+    update_time: '0.10'
+    width1: '1'
+    width10: '1'
+    width2: '1'
+    width3: '1'
+    width4: '1'
+    width5: '1'
+    width6: '1'
+    width7: '1'
+    width8: '1'
+    width9: '1'
+    xmax: '2'
+    xmin: '-2'
+    ymax: '2'
+    ymin: '-2'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [1200, 364.0]
+    rotation: 0
+    state: enabled
+- name: qtgui_freq_sink_x_0
+  id: qtgui_freq_sink_x
+  parameters:
+    affinity: ''
+    alias: ''
+    alpha1: '1.0'
+    alpha10: '1.0'
+    alpha2: '1.0'
+    alpha3: '1.0'
+    alpha4: '1.0'
+    alpha5: '1.0'
+    alpha6: '1.0'
+    alpha7: '1.0'
+    alpha8: '1.0'
+    alpha9: '1.0'
+    autoscale: 'False'
+    average: '1.0'
+    axislabels: 'True'
+    bw: samp_rate
+    color1: '"blue"'
+    color10: '"dark blue"'
+    color2: '"red"'
+    color3: '"green"'
+    color4: '"black"'
+    color5: '"cyan"'
+    color6: '"magenta"'
+    color7: '"yellow"'
+    color8: '"dark red"'
+    color9: '"dark green"'
+    comment: ''
+    ctrlpanel: 'False'
+    fc: '0'
+    fftsize: '1024'
+    freqhalf: 'True'
+    grid: 'False'
+    gui_hint: 3,0,1,1
+    label: Relative Gain
+    label1: ''
+    label10: ''''''
+    label2: ''''''
+    label3: ''''''
+    label4: ''''''
+    label5: ''''''
+    label6: ''''''
+    label7: ''''''
+    label8: ''''''
+    label9: ''''''
+    legend: 'True'
+    maxoutbuf: '0'
+    minoutbuf: '0'
+    name: '"Channel Input"'
+    nconnections: '1'
+    showports: 'False'
+    tr_chan: '0'
+    tr_level: '0.0'
+    tr_mode: qtgui.TRIG_MODE_FREE
+    tr_tag: '""'
+    type: complex
+    units: dB
+    update_time: '0.10'
+    width1: '1'
+    width10: '1'
+    width2: '1'
+    width3: '1'
+    width4: '1'
+    width5: '1'
+    width6: '1'
+    width7: '1'
+    width8: '1'
+    width9: '1'
+    wintype: firdes.WIN_BLACKMAN_hARRIS
+    ymax: '10'
+    ymin: '-140'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [920, 56.0]
+    rotation: 0
+    state: true
+- name: qtgui_time_sink_x_0
+  id: qtgui_time_sink_x
+  parameters:
+    affinity: ''
+    alias: ''
+    alpha1: '1.0'
+    alpha10: '1.0'
+    alpha2: '1.0'
+    alpha3: '1.0'
+    alpha4: '1.0'
+    alpha5: '1.0'
+    alpha6: '1.0'
+    alpha7: '1.0'
+    alpha8: '1.0'
+    alpha9: '1.0'
+    autoscale: 'False'
+    axislabels: 'True'
+    color1: blue
+    color10: dark blue
+    color2: red
+    color3: green
+    color4: black
+    color5: cyan
+    color6: magenta
+    color7: yellow
+    color8: dark red
+    color9: dark green
+    comment: ''
+    ctrlpanel: 'False'
+    entags: 'True'
+    grid: 'False'
+    gui_hint: 2,0,1,1
+    label1: Signal 1
+    label10: Signal 10
+    label2: Signal 2
+    label3: Signal 3
+    label4: Signal 4
+    label5: Signal 5
+    label6: Signal 6
+    label7: Signal 7
+    label8: Signal 8
+    label9: Signal 9
+    legend: 'True'
+    marker1: '-1'
+    marker10: '-1'
+    marker2: '-1'
+    marker3: '-1'
+    marker4: '-1'
+    marker5: '-1'
+    marker6: '-1'
+    marker7: '-1'
+    marker8: '-1'
+    marker9: '-1'
+    name: '"Channel Input Spectrum"'
+    nconnections: '1'
+    size: '1024'
+    srate: samp_rate
+    stemplot: 'False'
+    style1: '1'
+    style10: '1'
+    style2: '1'
+    style3: '1'
+    style4: '1'
+    style5: '1'
+    style6: '1'
+    style7: '1'
+    style8: '1'
+    style9: '1'
+    tr_chan: '0'
+    tr_delay: '0'
+    tr_level: '0.0'
+    tr_mode: qtgui.TRIG_MODE_FREE
+    tr_slope: qtgui.TRIG_SLOPE_POS
+    tr_tag: '""'
+    type: complex
+    update_time: '0.10'
+    width1: '1'
+    width10: '1'
+    width2: '1'
+    width3: '1'
+    width4: '1'
+    width5: '1'
+    width6: '1'
+    width7: '1'
+    width8: '1'
+    width9: '1'
+    ylabel: Amplitude
+    ymax: '1'
+    ymin: '-1'
+    yunit: '""'
+  states:
+    bus_sink: false
+    bus_source: false
+    bus_structure: null
+    coordinate: [920, 172.0]
+    rotation: 0
+    state: enabled
+
+connections:
+- [analog_random_source_x_0, '0', digital_constellation_modulator_0, '0']
+- [blocks_throttle_0, '0', channels_channel_model_0, '0']
+- [channels_channel_model_0, '0', digital_pfb_clock_sync_xxx_0, '0']
+- [channels_channel_model_0, '0', qtgui_const_sink_x_0, '0']
+- [channels_channel_model_0, '0', qtgui_freq_sink_x_0, '0']
+- [channels_channel_model_0, '0', qtgui_time_sink_x_0, '0']
+- [digital_constellation_modulator_0, '0', blocks_throttle_0, '0']
+- [digital_pfb_clock_sync_xxx_0, '0', qtgui_const_sink_x_0_0, '0']
+
+metadata:
+  file_format: 1
diff --git a/tests/Simulation/QPKS/qpks.py b/tests/Simulation/QPKS/qpks.py
new file mode 100755
index 0000000..4027eb3
--- /dev/null
+++ b/tests/Simulation/QPKS/qpks.py
@@ -0,0 +1,460 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+#
+# SPDX-License-Identifier: GPL-3.0
+#
+# GNU Radio Python Flow Graph
+# Title: QPSK
+# GNU Radio version: 3.8.2.0
+
+from distutils.version import StrictVersion
+
+if __name__ == '__main__':
+    import ctypes
+    import sys
+    if sys.platform.startswith('linux'):
+        try:
+            x11 = ctypes.cdll.LoadLibrary('libX11.so')
+            x11.XInitThreads()
+        except:
+            print("Warning: failed to XInitThreads()")
+
+from PyQt5 import Qt
+from gnuradio import qtgui
+from gnuradio.filter import firdes
+import sip
+from gnuradio import blocks
+import numpy
+from gnuradio import channels
+from gnuradio import digital
+from gnuradio import gr
+import sys
+import signal
+from argparse import ArgumentParser
+from gnuradio.eng_arg import eng_float, intx
+from gnuradio import eng_notation
+from gnuradio.qtgui import Range, RangeWidget
+
+from gnuradio import qtgui
+
+class qpks(gr.top_block, Qt.QWidget):
+
+    def __init__(self):
+        gr.top_block.__init__(self, "QPSK")
+        Qt.QWidget.__init__(self)
+        self.setWindowTitle("QPSK")
+        qtgui.util.check_set_qss()
+        try:
+            self.setWindowIcon(Qt.QIcon.fromTheme('gnuradio-grc'))
+        except:
+            pass
+        self.top_scroll_layout = Qt.QVBoxLayout()
+        self.setLayout(self.top_scroll_layout)
+        self.top_scroll = Qt.QScrollArea()
+        self.top_scroll.setFrameStyle(Qt.QFrame.NoFrame)
+        self.top_scroll_layout.addWidget(self.top_scroll)
+        self.top_scroll.setWidgetResizable(True)
+        self.top_widget = Qt.QWidget()
+        self.top_scroll.setWidget(self.top_widget)
+        self.top_layout = Qt.QVBoxLayout(self.top_widget)
+        self.top_grid_layout = Qt.QGridLayout()
+        self.top_layout.addLayout(self.top_grid_layout)
+
+        self.settings = Qt.QSettings("GNU Radio", "qpks")
+
+        try:
+            if StrictVersion(Qt.qVersion()) < StrictVersion("5.0.0"):
+                self.restoreGeometry(self.settings.value("geometry").toByteArray())
+            else:
+                self.restoreGeometry(self.settings.value("geometry"))
+        except:
+            pass
+
+        ##################################################
+        # Variables
+        ##################################################
+        self.sps = sps = 4
+        self.nfilts = nfilts = 32
+        self.timing_loop_bw = timing_loop_bw = 2 * 3.141592653589793 / 100
+        self.time_offset = time_offset = 1.0
+        self.taps = taps = [1.0 + 0.0j, ]
+        self.samp_rate = samp_rate = 32000
+        self.rrc_taps = rrc_taps = firdes.root_raised_cosine(nfilts, nfilts, 1.0/float(sps), 0.35, 45*nfilts)
+        self.qpsk_const = qpsk_const = digital.constellation_rect([0.707+0.707j, -0.707+0.707j, -0.707-0.707j, 0.707-0.707j], [0, 1, 3, 2],
+        4, 2, 2, 1, 1).base()
+        self.noise_volt = noise_volt = 0.0001
+        self.freq_offset = freq_offset = 0
+        self.excess_bw = excess_bw = 350e-3
+
+        ##################################################
+        # Blocks
+        ##################################################
+        self._timing_loop_bw_range = Range(0, 200e-3, 10e-3, 2 * 3.141592653589793 / 100, 200)
+        self._timing_loop_bw_win = RangeWidget(self._timing_loop_bw_range, self.set_timing_loop_bw, 'Time: BW', "counter_slider", float)
+        self.top_grid_layout.addWidget(self._timing_loop_bw_win, 1, 1, 1, 1)
+        for r in range(1, 2):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(1, 2):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self._time_offset_range = Range(0.999, 1.001, 0.0001, 1.0, 200)
+        self._time_offset_win = RangeWidget(self._time_offset_range, self.set_time_offset, 'Timing Offset', "counter_slider", float)
+        self.top_grid_layout.addWidget(self._time_offset_win, 0, 1, 1, 1)
+        for r in range(0, 1):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(1, 2):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self._noise_volt_range = Range(0, 1, 0.01, 0.0001, 200)
+        self._noise_volt_win = RangeWidget(self._noise_volt_range, self.set_noise_volt, 'Noise Voltage', "counter_slider", float)
+        self.top_grid_layout.addWidget(self._noise_volt_win, 0, 0, 1, 1)
+        for r in range(0, 1):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(0, 1):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self._freq_offset_range = Range(-100e-3, 100e-3, 1e-3, 0, 200)
+        self._freq_offset_win = RangeWidget(self._freq_offset_range, self.set_freq_offset, 'Frequency Offset', "counter_slider", float)
+        self.top_grid_layout.addWidget(self._freq_offset_win, 1, 0, 1, 1)
+        for r in range(1, 2):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(0, 1):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self.qtgui_time_sink_x_0 = qtgui.time_sink_c(
+            1024, #size
+            samp_rate, #samp_rate
+            "Channel Input Spectrum", #name
+            1 #number of inputs
+        )
+        self.qtgui_time_sink_x_0.set_update_time(0.10)
+        self.qtgui_time_sink_x_0.set_y_axis(-1, 1)
+
+        self.qtgui_time_sink_x_0.set_y_label('Amplitude', "")
+
+        self.qtgui_time_sink_x_0.enable_tags(True)
+        self.qtgui_time_sink_x_0.set_trigger_mode(qtgui.TRIG_MODE_FREE, qtgui.TRIG_SLOPE_POS, 0.0, 0, 0, "")
+        self.qtgui_time_sink_x_0.enable_autoscale(False)
+        self.qtgui_time_sink_x_0.enable_grid(False)
+        self.qtgui_time_sink_x_0.enable_axis_labels(True)
+        self.qtgui_time_sink_x_0.enable_control_panel(False)
+        self.qtgui_time_sink_x_0.enable_stem_plot(False)
+
+
+        labels = ['Signal 1', 'Signal 2', 'Signal 3', 'Signal 4', 'Signal 5',
+            'Signal 6', 'Signal 7', 'Signal 8', 'Signal 9', 'Signal 10']
+        widths = [1, 1, 1, 1, 1,
+            1, 1, 1, 1, 1]
+        colors = ['blue', 'red', 'green', 'black', 'cyan',
+            'magenta', 'yellow', 'dark red', 'dark green', 'dark blue']
+        alphas = [1.0, 1.0, 1.0, 1.0, 1.0,
+            1.0, 1.0, 1.0, 1.0, 1.0]
+        styles = [1, 1, 1, 1, 1,
+            1, 1, 1, 1, 1]
+        markers = [-1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1]
+
+
+        for i in range(2):
+            if len(labels[i]) == 0:
+                if (i % 2 == 0):
+                    self.qtgui_time_sink_x_0.set_line_label(i, "Re{{Data {0}}}".format(i/2))
+                else:
+                    self.qtgui_time_sink_x_0.set_line_label(i, "Im{{Data {0}}}".format(i/2))
+            else:
+                self.qtgui_time_sink_x_0.set_line_label(i, labels[i])
+            self.qtgui_time_sink_x_0.set_line_width(i, widths[i])
+            self.qtgui_time_sink_x_0.set_line_color(i, colors[i])
+            self.qtgui_time_sink_x_0.set_line_style(i, styles[i])
+            self.qtgui_time_sink_x_0.set_line_marker(i, markers[i])
+            self.qtgui_time_sink_x_0.set_line_alpha(i, alphas[i])
+
+        self._qtgui_time_sink_x_0_win = sip.wrapinstance(self.qtgui_time_sink_x_0.pyqwidget(), Qt.QWidget)
+        self.top_grid_layout.addWidget(self._qtgui_time_sink_x_0_win, 2, 0, 1, 1)
+        for r in range(2, 3):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(0, 1):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self.qtgui_freq_sink_x_0 = qtgui.freq_sink_c(
+            1024, #size
+            firdes.WIN_BLACKMAN_hARRIS, #wintype
+            0, #fc
+            samp_rate, #bw
+            "Channel Input", #name
+            1
+        )
+        self.qtgui_freq_sink_x_0.set_update_time(0.10)
+        self.qtgui_freq_sink_x_0.set_y_axis(-140, 10)
+        self.qtgui_freq_sink_x_0.set_y_label('Relative Gain', 'dB')
+        self.qtgui_freq_sink_x_0.set_trigger_mode(qtgui.TRIG_MODE_FREE, 0.0, 0, "")
+        self.qtgui_freq_sink_x_0.enable_autoscale(False)
+        self.qtgui_freq_sink_x_0.enable_grid(False)
+        self.qtgui_freq_sink_x_0.set_fft_average(1.0)
+        self.qtgui_freq_sink_x_0.enable_axis_labels(True)
+        self.qtgui_freq_sink_x_0.enable_control_panel(False)
+
+
+
+        labels = ['', '', '', '', '',
+            '', '', '', '', '']
+        widths = [1, 1, 1, 1, 1,
+            1, 1, 1, 1, 1]
+        colors = ["blue", "red", "green", "black", "cyan",
+            "magenta", "yellow", "dark red", "dark green", "dark blue"]
+        alphas = [1.0, 1.0, 1.0, 1.0, 1.0,
+            1.0, 1.0, 1.0, 1.0, 1.0]
+
+        for i in range(1):
+            if len(labels[i]) == 0:
+                self.qtgui_freq_sink_x_0.set_line_label(i, "Data {0}".format(i))
+            else:
+                self.qtgui_freq_sink_x_0.set_line_label(i, labels[i])
+            self.qtgui_freq_sink_x_0.set_line_width(i, widths[i])
+            self.qtgui_freq_sink_x_0.set_line_color(i, colors[i])
+            self.qtgui_freq_sink_x_0.set_line_alpha(i, alphas[i])
+
+        self._qtgui_freq_sink_x_0_win = sip.wrapinstance(self.qtgui_freq_sink_x_0.pyqwidget(), Qt.QWidget)
+        self.top_grid_layout.addWidget(self._qtgui_freq_sink_x_0_win, 3, 0, 1, 1)
+        for r in range(3, 4):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(0, 1):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self.qtgui_const_sink_x_0_0 = qtgui.const_sink_c(
+            2048, #size
+            "After Clock Sync", #name
+            1 #number of inputs
+        )
+        self.qtgui_const_sink_x_0_0.set_update_time(0.10)
+        self.qtgui_const_sink_x_0_0.set_y_axis(-2, 2)
+        self.qtgui_const_sink_x_0_0.set_x_axis(-2, 2)
+        self.qtgui_const_sink_x_0_0.set_trigger_mode(qtgui.TRIG_MODE_FREE, qtgui.TRIG_SLOPE_POS, 0.0, 0, "")
+        self.qtgui_const_sink_x_0_0.enable_autoscale(False)
+        self.qtgui_const_sink_x_0_0.enable_grid(False)
+        self.qtgui_const_sink_x_0_0.enable_axis_labels(True)
+
+
+        labels = ['', '', '', '', '',
+            '', '', '', '', '']
+        widths = [1, 1, 1, 1, 1,
+            1, 1, 1, 1, 1]
+        colors = ["blue", "red", "red", "red", "red",
+            "red", "red", "red", "red", "red"]
+        styles = [0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0]
+        markers = [0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0]
+        alphas = [1.0, 1.0, 1.0, 1.0, 1.0,
+            1.0, 1.0, 1.0, 1.0, 1.0]
+
+        for i in range(1):
+            if len(labels[i]) == 0:
+                self.qtgui_const_sink_x_0_0.set_line_label(i, "Data {0}".format(i))
+            else:
+                self.qtgui_const_sink_x_0_0.set_line_label(i, labels[i])
+            self.qtgui_const_sink_x_0_0.set_line_width(i, widths[i])
+            self.qtgui_const_sink_x_0_0.set_line_color(i, colors[i])
+            self.qtgui_const_sink_x_0_0.set_line_style(i, styles[i])
+            self.qtgui_const_sink_x_0_0.set_line_marker(i, markers[i])
+            self.qtgui_const_sink_x_0_0.set_line_alpha(i, alphas[i])
+
+        self._qtgui_const_sink_x_0_0_win = sip.wrapinstance(self.qtgui_const_sink_x_0_0.pyqwidget(), Qt.QWidget)
+        self.top_grid_layout.addWidget(self._qtgui_const_sink_x_0_0_win, 3, 1, 1, 1)
+        for r in range(3, 4):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(1, 2):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self.qtgui_const_sink_x_0 = qtgui.const_sink_c(
+            2048, #size
+            "After Channel", #name
+            1 #number of inputs
+        )
+        self.qtgui_const_sink_x_0.set_update_time(0.10)
+        self.qtgui_const_sink_x_0.set_y_axis(-2, 2)
+        self.qtgui_const_sink_x_0.set_x_axis(-2, 2)
+        self.qtgui_const_sink_x_0.set_trigger_mode(qtgui.TRIG_MODE_FREE, qtgui.TRIG_SLOPE_POS, 0.0, 0, "")
+        self.qtgui_const_sink_x_0.enable_autoscale(False)
+        self.qtgui_const_sink_x_0.enable_grid(False)
+        self.qtgui_const_sink_x_0.enable_axis_labels(True)
+
+
+        labels = ['', '', '', '', '',
+            '', '', '', '', '']
+        widths = [1, 1, 1, 1, 1,
+            1, 1, 1, 1, 1]
+        colors = ["blue", "red", "red", "red", "red",
+            "red", "red", "red", "red", "red"]
+        styles = [0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0]
+        markers = [0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0]
+        alphas = [1.0, 1.0, 1.0, 1.0, 1.0,
+            1.0, 1.0, 1.0, 1.0, 1.0]
+
+        for i in range(1):
+            if len(labels[i]) == 0:
+                self.qtgui_const_sink_x_0.set_line_label(i, "Data {0}".format(i))
+            else:
+                self.qtgui_const_sink_x_0.set_line_label(i, labels[i])
+            self.qtgui_const_sink_x_0.set_line_width(i, widths[i])
+            self.qtgui_const_sink_x_0.set_line_color(i, colors[i])
+            self.qtgui_const_sink_x_0.set_line_style(i, styles[i])
+            self.qtgui_const_sink_x_0.set_line_marker(i, markers[i])
+            self.qtgui_const_sink_x_0.set_line_alpha(i, alphas[i])
+
+        self._qtgui_const_sink_x_0_win = sip.wrapinstance(self.qtgui_const_sink_x_0.pyqwidget(), Qt.QWidget)
+        self.top_grid_layout.addWidget(self._qtgui_const_sink_x_0_win, 2, 1, 1, 1)
+        for r in range(2, 3):
+            self.top_grid_layout.setRowStretch(r, 1)
+        for c in range(1, 2):
+            self.top_grid_layout.setColumnStretch(c, 1)
+        self.digital_pfb_clock_sync_xxx_0 = digital.pfb_clock_sync_ccf(sps * 1.001, timing_loop_bw, rrc_taps, nfilts, nfilts/2, 1.5, 1)
+        self.digital_constellation_modulator_0 = digital.generic_mod(
+            constellation=qpsk_const,
+            differential=True,
+            samples_per_symbol=sps,
+            pre_diff_code=True,
+            excess_bw=excess_bw,
+            verbose=False,
+            log=False)
+        self.channels_channel_model_0 = channels.channel_model(
+            noise_voltage=noise_volt,
+            frequency_offset=freq_offset,
+            epsilon=time_offset,
+            taps=taps,
+            noise_seed=0,
+            block_tags=False)
+        self.blocks_throttle_0 = blocks.throttle(gr.sizeof_gr_complex*1, samp_rate,True)
+        self.analog_random_source_x_0 = blocks.vector_source_b(list(map(int, numpy.random.randint(0, 2, 1000))), True)
+
+
+
+        ##################################################
+        # Connections
+        ##################################################
+        self.connect((self.analog_random_source_x_0, 0), (self.digital_constellation_modulator_0, 0))
+        self.connect((self.blocks_throttle_0, 0), (self.channels_channel_model_0, 0))
+        self.connect((self.channels_channel_model_0, 0), (self.digital_pfb_clock_sync_xxx_0, 0))
+        self.connect((self.channels_channel_model_0, 0), (self.qtgui_const_sink_x_0, 0))
+        self.connect((self.channels_channel_model_0, 0), (self.qtgui_freq_sink_x_0, 0))
+        self.connect((self.channels_channel_model_0, 0), (self.qtgui_time_sink_x_0, 0))
+        self.connect((self.digital_constellation_modulator_0, 0), (self.blocks_throttle_0, 0))
+        self.connect((self.digital_pfb_clock_sync_xxx_0, 0), (self.qtgui_const_sink_x_0_0, 0))
+
+
+    def closeEvent(self, event):
+        self.settings = Qt.QSettings("GNU Radio", "qpks")
+        self.settings.setValue("geometry", self.saveGeometry())
+        event.accept()
+
+    def get_sps(self):
+        return self.sps
+
+    def set_sps(self, sps):
+        self.sps = sps
+        self.set_rrc_taps(firdes.root_raised_cosine(self.nfilts, self.nfilts, 1.0/float(self.sps), 0.35, 45*self.nfilts))
+
+    def get_nfilts(self):
+        return self.nfilts
+
+    def set_nfilts(self, nfilts):
+        self.nfilts = nfilts
+        self.set_rrc_taps(firdes.root_raised_cosine(self.nfilts, self.nfilts, 1.0/float(self.sps), 0.35, 45*self.nfilts))
+
+    def get_timing_loop_bw(self):
+        return self.timing_loop_bw
+
+    def set_timing_loop_bw(self, timing_loop_bw):
+        self.timing_loop_bw = timing_loop_bw
+        self.digital_pfb_clock_sync_xxx_0.set_loop_bandwidth(self.timing_loop_bw)
+
+    def get_time_offset(self):
+        return self.time_offset
+
+    def set_time_offset(self, time_offset):
+        self.time_offset = time_offset
+        self.channels_channel_model_0.set_timing_offset(self.time_offset)
+
+    def get_taps(self):
+        return self.taps
+
+    def set_taps(self, taps):
+        self.taps = taps
+        self.channels_channel_model_0.set_taps(self.taps)
+
+    def get_samp_rate(self):
+        return self.samp_rate
+
+    def set_samp_rate(self, samp_rate):
+        self.samp_rate = samp_rate
+        self.blocks_throttle_0.set_sample_rate(self.samp_rate)
+        self.qtgui_freq_sink_x_0.set_frequency_range(0, self.samp_rate)
+        self.qtgui_time_sink_x_0.set_samp_rate(self.samp_rate)
+
+    def get_rrc_taps(self):
+        return self.rrc_taps
+
+    def set_rrc_taps(self, rrc_taps):
+        self.rrc_taps = rrc_taps
+        self.digital_pfb_clock_sync_xxx_0.update_taps(self.rrc_taps)
+
+    def get_qpsk_const(self):
+        return self.qpsk_const
+
+    def set_qpsk_const(self, qpsk_const):
+        self.qpsk_const = qpsk_const
+
+    def get_noise_volt(self):
+        return self.noise_volt
+
+    def set_noise_volt(self, noise_volt):
+        self.noise_volt = noise_volt
+        self.channels_channel_model_0.set_noise_voltage(self.noise_volt)
+
+    def get_freq_offset(self):
+        return self.freq_offset
+
+    def set_freq_offset(self, freq_offset):
+        self.freq_offset = freq_offset
+        self.channels_channel_model_0.set_frequency_offset(self.freq_offset)
+
+    def get_excess_bw(self):
+        return self.excess_bw
+
+    def set_excess_bw(self, excess_bw):
+        self.excess_bw = excess_bw
+
+
+
+
+
+def main(top_block_cls=qpks, options=None):
+    if gr.enable_realtime_scheduling() != gr.RT_OK:
+        print("Error: failed to enable real-time scheduling.")
+
+    if StrictVersion("4.5.0") <= StrictVersion(Qt.qVersion()) < StrictVersion("5.0.0"):
+        style = gr.prefs().get_string('qtgui', 'style', 'raster')
+        Qt.QApplication.setGraphicsSystem(style)
+    qapp = Qt.QApplication(sys.argv)
+
+    tb = top_block_cls()
+
+    tb.start()
+
+    tb.show()
+
+    def sig_handler(sig=None, frame=None):
+        Qt.QApplication.quit()
+
+    signal.signal(signal.SIGINT, sig_handler)
+    signal.signal(signal.SIGTERM, sig_handler)
+
+    timer = Qt.QTimer()
+    timer.start(500)
+    timer.timeout.connect(lambda: None)
+
+    def quitting():
+        tb.stop()
+        tb.wait()
+
+    qapp.aboutToQuit.connect(quitting)
+    qapp.exec_()
+
+if __name__ == '__main__':
+    main()