FM Loopback

Noisy FM transmitter and quadrature-demodulator loopback with live tone and noise controls

Author Claude
Category Analog
Blocks 10
Connections 7
File analog/fm_loopback.grc

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Blocks used

Block	Module	Used
QT GUI Range	`GNU Radio`	2
Add	`GNU Radio`	1
Frequency Mod	`GNU Radio`	1
Noise Source	`GNU Radio`	1
QT GUI Frequency Sink	`GNU Radio`	1
QT GUI Time Sink	`GNU Radio`	1
Quadrature Demod	`GNU Radio`	1
Signal Source	`GNU Radio`	1
Throttle	`GNU Radio`	1

Flowgraph source

analog/fm_loopback.grc

options:
    parameters:
        author: Claude
        copyright: ''
        description: Noisy FM transmitter and quadrature-demodulator loopback with live tone and noise controls
        generate_options: qt_gui
        id: FM_Loopback
        title: FM Loopback
    states:
        coordinate: [10, 10]
        rotation: 0
        state: enabled
blocks:
-   name: noise_amplitude
    id: variable_qtgui_range
    parameters:
        comment: ''
        label: Channel noise
        min_len: '240'
        orient: QtCore.Qt.Horizontal
        rangeType: float
        start: '0'
        step: '0.01'
        stop: '0.5'
        value: '0.05'
        widget: counter_slider
    states:
        coordinate: [590, 10]
        rotation: 0
        state: enabled
-   name: tone_frequency
    id: variable_qtgui_range
    parameters:
        comment: ''
        label: Message tone frequency
        min_len: '240'
        orient: QtCore.Qt.Horizontal
        rangeType: float
        start: '200'
        step: '100'
        stop: '3000'
        value: '1000'
        widget: counter_slider
    states:
        coordinate: [840, 10]
        rotation: 0
        state: enabled
-   name: channel_noise
    id: analog_noise_source_x
    parameters:
        affinity: ''
        alias: ''
        amplitude: noise_amplitude
        comment: ''
        maxoutbuf: '0'
        minoutbuf: '0'
        seed: '7'
        type: complex
    states:
        coordinate: [290, 340]
        rotation: 0
        state: enabled
-   name: fm_demodulator
    id: analog_quadrature_demod_cf
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        gain: '1.5278874537'
        maxoutbuf: '0'
        minoutbuf: '0'
    states:
        coordinate: [1220, 250]
        rotation: 0
        state: enabled
-   name: fm_modulator
    id: analog_frequency_modulator_fc
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        maxoutbuf: '0'
        minoutbuf: '0'
        sensitivity: '0.6544984695'
    states:
        coordinate: [290, 240]
        rotation: 0
        state: enabled
-   name: fm_spectrum
    id: qtgui_freq_sink_x
    parameters:
        affinity: ''
        alias: ''
        alpha1: '1'
        autoscale: 'False'
        average: '0.2'
        axislabels: 'True'
        color1: '"blue"'
        comment: ''
        ctrlpanel: 'False'
        fc: '0'
        fftsize: '2048'
        grid: 'True'
        label1: Noisy FM signal
        legend: 'True'
        marker1: '-1'
        maxoutbuf: '0'
        minoutbuf: '0'
        name: FM Channel Spectrum
        samp_rate: '48000'
        style1: '1'
        tr_chan: '0'
        tr_level: '0'
        tr_mode: qtgui.TRIG_MODE_FREE
        tr_tag: ''
        update_time: '0.1'
        width1: '1'
        ymax: '10'
        ymin: '-100'
    states:
        coordinate: [1220, 350]
        rotation: 0
        state: enabled
-   name: message_tone
    id: analog_sig_source_x
    parameters:
        affinity: ''
        alias: ''
        amplitude: '1'
        comment: ''
        frequency: tone_frequency
        maxoutbuf: '0'
        minoutbuf: '0'
        samp_rate: '48000'
        type: float
        waveform: analog.GR_COS_WAVE
    states:
        coordinate: [10, 220]
        rotation: 0
        state: enabled
-   name: noisy_channel
    id: blocks_add_xx
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        maxoutbuf: '0'
        minoutbuf: '0'
        num_inputs: '2'
        type: complex
        vlen: '1'
    states:
        coordinate: [650, 240]
        rotation: 0
        state: enabled
-   name: recovered_message
    id: qtgui_time_sink_x
    parameters:
        affinity: ''
        alias: ''
        alpha1: '1'
        alpha2: '1'
        autoscale: 'False'
        axislabels: 'True'
        color1: blue
        color2: red
        comment: ''
        ctrlpanel: 'False'
        grid: 'True'
        label1: Recovered tone
        label2: Signal 2
        legend: 'True'
        marker1: '-1'
        marker2: '-1'
        name: Recovered FM Message
        samp_rate: '48000'
        size: '1024'
        stemplot: 'False'
        style1: '1'
        style2: '1'
        tr_chan: '0'
        tr_delay: '0'
        tr_level: '0'
        tr_mode: qtgui.TRIG_MODE_FREE
        tr_slope: qtgui.TRIG_SLOPE_POS
        tr_tag: ''
        type: float
        update_time: '0.1'
        width1: '1'
        width2: '1'
        ylabel: Amplitude
        ymax: '1.5'
        ymin: '-1.5'
        yunit: ''
    states:
        coordinate: [80, 530]
        rotation: 0
        state: enabled
-   name: throttle
    id: blocks_throttle2
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        ignoretag: 'True'
        limit: auto
        maximum: '0.1'
        maxoutbuf: '0'
        minoutbuf: '0'
        samples_per_second: '48000'
        type: complex
        vlen: '1'
    states:
        coordinate: [890, 230]
        rotation: 0
        state: enabled
connections:
- [channel_noise, '0', noisy_channel, '1']
- [fm_demodulator, '0', recovered_message, '0']
- [fm_modulator, '0', noisy_channel, '0']
- [message_tone, '0', fm_modulator, '0']
- [noisy_channel, '0', throttle, '0']
- [throttle, '0', fm_demodulator, '0']
- [throttle, '0', fm_spectrum, '0']
metadata:
    file_format: 1
    grc_version: 3.11.0.0