FSK radar simulator

An FSK radar measuring one simulated target: two alternating tones bounce off something 200 m away closing at 20 m/s, and the range and velocity that come back out are plotted live. Move the target with the two sliders and watch the measurement follow it. Adapted from gr-radar's own examples/simulation/simulator_fsk.grc.
Author Communications Engineering Lab, KIT
Category gr-radar
Blocks 30
Connections 18
File gr-radar/fsk_radar_simulator.grc
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Blocks used

Block	Module	Used
Variable	`GNU Radio`	9
QT GUI Range	`GNU Radio`	3
Multiply Conjugate	`GNU Radio`	2
QT GUI Time Plot	`gr-radar`	2
Tagged Stream FFT	`gr-radar`	2
Add	`GNU Radio`	1
Estimator FSK	`gr-radar`	1
GUI Layout	`GNU Radio`	1
Message Gate	`gr-radar`	1
Noise Source	`GNU Radio`	1
OS-CFAR	`gr-radar`	1
Print Results	`gr-radar`	1
QT GUI Scatter Plot	`gr-radar`	1
Signal Generator FSK	`gr-radar`	1
Split FSK	`gr-radar`	1
Static Target Simulator	`gr-radar`	1
Throttle	`GNU Radio`	1
Flowgraph source

gr-radar/fsk_radar_simulator.grc
options:
    parameters:
        author: Communications Engineering Lab, KIT
        comment: ''
        copyright: ''
        description: 'An FSK radar measuring one simulated target: two alternating tones bounce off something 200 m away closing at 20 m/s, and the range and velocity that come back out are plotted live. Move the target with the two sliders and watch the measurement follow it. Adapted from gr-radar''s own examples/simulation/simulator_fsk.grc.'
        generate_options: qt_gui
        id: FSK_radar_simulator
        title: FSK radar simulator
    states:
        coordinate: [10, 10]
        rotation: 0
        state: enabled
blocks:
-   name: R_max
    id: variable
    parameters:
        comment: Unambiguous range, metres
        value: 3e8/2/delta_freq
    states:
        coordinate: [1420, 20]
        rotation: 0
        state: enabled
-   name: blocks_per_tag
    id: variable
    parameters:
        comment: Tone pairs per measurement
        value: '16384'
    states:
        coordinate: [890, 20]
        rotation: 0
        state: enabled
-   name: center_freq
    id: variable
    parameters:
        comment: "Carrier the Doppler shift\nis measured against"
        value: '2400000000'
    states:
        coordinate: [490, 20]
        rotation: 0
        state: enabled
-   name: cfar_mult
    id: variable_qtgui_range
    parameters:
        comment: Raises the detector's threshold above the noise floor
        label: CFAR threshold multiplier
        min_len: '200'
        orient: QtCore.Qt.Horizontal
        rangeType: float
        start: '1'
        step: '1'
        stop: '60'
        value: '45'
        widget: counter_slider
    states:
        coordinate: [1100, 170]
        rotation: 0
        state: enabled
-   name: delta_freq
    id: variable
    parameters:
        comment: "Tone spacing; range comes from\nthe phase difference between the two"
        value: samp_rate/4
    states:
        coordinate: [1130, 20]
        rotation: 0
        state: enabled
-   name: freq_res
    id: variable
    parameters:
        comment: ''
        value: samp_rate/2/blocks_per_tag
    states:
        coordinate: [10, 150]
        rotation: 0
        state: enabled
-   name: min_output_buffer
    id: variable
    parameters:
        comment: "Two packets, so every\ntagged-stream block has\nroom for one"
        value: 4*blocks_per_tag*samp_per_freq
    states:
        coordinate: [1410, 170]
        rotation: 0
        state: enabled
-   name: samp_per_freq
    id: variable
    parameters:
        comment: ''
        value: '1'
    states:
        coordinate: [680, 20]
        rotation: 0
        state: enabled
-   name: samp_rate
    id: variable
    parameters:
        comment: ''
        value: '1000000'
    states:
        coordinate: [320, 20]
        rotation: 0
        state: enabled
-   name: target_range
    id: variable_qtgui_range
    parameters:
        comment: ''
        label: Target Range [m]
        min_len: '200'
        orient: QtCore.Qt.Horizontal
        rangeType: float
        start: '50'
        step: '1'
        stop: '500'
        value: '200'
        widget: counter_slider
    states:
        coordinate: [500, 150]
        rotation: 0
        state: enabled
-   name: target_velocity
    id: variable_qtgui_range
    parameters:
        comment: ''
        label: Target Velocity [m/s]
        min_len: '200'
        orient: QtCore.Qt.Horizontal
        rangeType: float
        start: '5'
        step: '1'
        stop: '50'
        value: '20'
        widget: counter_slider
    states:
        coordinate: [790, 160]
        rotation: 0
        state: enabled
-   name: v_res
    id: variable
    parameters:
        comment: Velocity resolution, m/s
        value: freq_res*3e8/2/center_freq
    states:
        coordinate: [240, 150]
        rotation: 0
        state: enabled
-   name: add
    id: blocks_add_xx
    parameters:
        affinity: ''
        alias: ''
        comment: Echo plus receiver noise
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        num_inputs: '2'
        type: complex
        vlen: '1'
    states:
        coordinate: [1100, 410]
        rotation: 0
        state: enabled
-   name: cfar
    id: radar_os_cfar_c
    parameters:
        affinity: ''
        alias: ''
        comment: Constant-false-alarm-rate peak detector
        len_key: '"packet_len"'
        maxoutbuf: '0'
        merge_consecutive: 'True'
        minoutbuf: min_output_buffer
        mult_threshold: cfar_mult
        rel_threshold: '0.78'
        samp_compare: '15'
        samp_protect: '0'
        samp_rate: samp_rate//2
    states:
        coordinate: [110, 1140]
        rotation: 0
        state: enabled
-   name: cross
    id: blocks_multiply_conjugate_cc
    parameters:
        affinity: ''
        alias: ''
        comment: Phase difference between the two tones' spectra
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        vlen: '1'
    states:
        coordinate: [1090, 900]
        rotation: 0
        state: enabled
-   name: dechirp
    id: blocks_multiply_conjugate_cc
    parameters:
        affinity: ''
        alias: ''
        comment: Mixes the echo down against the transmitted signal
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        vlen: '1'
    states:
        coordinate: [1360, 480]
        rotation: 0
        state: enabled
-   name: estimator
    id: radar_estimator_fsk
    parameters:
        affinity: ''
        alias: ''
        center_freq: center_freq
        comment: Peak position gives velocity, peak phase gives range
        delta_freq: delta_freq
        maxoutbuf: '0'
        minoutbuf: '0'
        push_power: 'False'
    states:
        coordinate: [570, 1180]
        rotation: 0
        state: enabled
-   name: fft_high
    id: radar_ts_fft_cc
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        len_key: '"packet_len"'
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        packet_len: blocks_per_tag*samp_per_freq
    states:
        coordinate: [630, 980]
        rotation: 0
        state: enabled
-   name: fft_low
    id: radar_ts_fft_cc
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        len_key: '"packet_len"'
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        packet_len: blocks_per_tag*samp_per_freq
    states:
        coordinate: [630, 870]
        rotation: 0
        state: enabled
-   name: fsk_gen
    id: radar_signal_generator_fsk_c
    parameters:
        affinity: ''
        alias: ''
        amplitude: '1'
        blocks_per_tag: blocks_per_tag
        comment: ''
        freq_high: delta_freq/2
        freq_low: -delta_freq/2
        len_key: '"packet_len"'
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        samp_per_freq: samp_per_freq
        samp_rate: samp_rate
    states:
        coordinate: [20, 450]
        rotation: 0
        state: enabled
-   name: gate
    id: radar_msg_gate
    parameters:
        affinity: ''
        alias: ''
        comment: "Drops detections outside the\nplotted velocity range -- chiefly\nthe residual of the tone step itself,\nwhich lands near -delta_freq"
        maxoutbuf: '0'
        minoutbuf: '0'
        msg_keys: ('velocity',)
        val_max: '[60]'
        val_min: '[-60]'
    states:
        coordinate: [1080, 1180]
        rotation: 0
        state: enabled
-   name: noise
    id: analog_noise_source_x
    parameters:
        affinity: ''
        alias: ''
        amplitude: '0.5'
        comment: ''
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        seed: '0'
        type: complex
    states:
        coordinate: [810, 410]
        rotation: 0
        state: enabled
-   name: range_plot
    id: radar_qtgui_time_plot
    parameters:
        affinity: ''
        alias: ''
        axis_y: '[0, 550]'
        comment: ''
        interval: '100'
        label: ''
        label_y: '''range'''
        range_time: '10'
    states:
        coordinate: [1580, 920]
        rotation: 0
        state: enabled
-   name: results
    id: radar_print_results
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        filename: '""'
        store_msg: 'False'
    states:
        coordinate: [1580, 820]
        rotation: 0
        state: enabled
-   name: scatter
    id: radar_qtgui_scatter_plot
    parameters:
        affinity: ''
        alias: ''
        axis_x: '[0, 550]'
        axis_y: '[-10, 60]'
        comment: ''
        interval: '250'
        label: ''
        label_x: '''range'''
        label_y: '''velocity'''
    states:
        coordinate: [1580, 1280]
        rotation: 0
        state: enabled
-   name: split
    id: radar_split_fsk_cc
    parameters:
        affinity: ''
        alias: ''
        comment: One stream per tone
        len_key: '"packet_len"'
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        samp_discard: '0'
        samp_per_freq: samp_per_freq
    states:
        coordinate: [100, 890]
        rotation: 0
        state: enabled
-   name: target
    id: radar_static_target_simulator_cc
    parameters:
        affinity: ''
        alias: ''
        azimuth: '[0]'
        center_freq: center_freq
        comment: Delays and Doppler-shifts the transmitted tones
        len_key: '"packet_len"'
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        position_rx: '[0]'
        range: target_range
        rcs: '[1e16]'
        rndm_phaseshift: 'True'
        samp_rate: samp_rate
        self_coupling: 'False'
        self_coupling_db: '-10'
        velocity: target_velocity
    states:
        coordinate: [750, 580]
        rotation: 0
        state: enabled
-   name: throttle
    id: blocks_throttle2
    parameters:
        affinity: ''
        alias: ''
        comment: ''
        ignoretag: 'True'
        limit: auto
        maximum: '0.1'
        maxoutbuf: '0'
        minoutbuf: min_output_buffer
        samples_per_second: samp_rate
        type: complex
        vlen: '1'
    states:
        coordinate: [470, 490]
        rotation: 0
        state: enabled
-   name: velocity_plot
    id: radar_qtgui_time_plot
    parameters:
        affinity: ''
        alias: ''
        axis_y: '[-10, 60]'
        comment: ''
        interval: '100'
        label: ''
        label_y: '''velocity'''
        range_time: '10'
    states:
        coordinate: [1580, 1100]
        rotation: 0
        state: enabled
-   name: wasm_gui_layout_0
    id: wasm_gui_layout
    parameters:
        affinity: ''
        alias: ''
        columns: '12'
        comment: ''
        layout: '{"cfar_mult":[3,1,6,1],"range_plot":[0,2,6,6],"scatter":[0,8,12,6],"target_range":[0,0,6,1],"target_velocity":[6,0,6,1],"velocity_plot":[6,2,6,6]}'
        row_height: '60'
    states:
        coordinate: [1670, 40]
        rotation: 0
        state: enabled
connections:
- [add, '0', dechirp, '0']
-   src_blk_id: cfar
    src_port_id: Msg out
    snk_blk_id: estimator
    snk_port_id: Msg in
- [cross, '0', cfar, '0']
- [dechirp, '0', split, '0']
-   src_blk_id: estimator
    src_port_id: Msg out
    snk_blk_id: gate
    snk_port_id: Msg in
- [fft_high, '0', cross, '0']
- [fft_low, '0', cross, '1']
- [fsk_gen, '0', throttle, '0']
-   src_blk_id: gate
    src_port_id: Msg out
    snk_blk_id: range_plot
    snk_port_id: Msg in
-   src_blk_id: gate
    src_port_id: Msg out
    snk_blk_id: results
    snk_port_id: Msg in
-   src_blk_id: gate
    src_port_id: Msg out
    snk_blk_id: scatter
    snk_port_id: Msg in
-   src_blk_id: gate
    src_port_id: Msg out
    snk_blk_id: velocity_plot
    snk_port_id: Msg in
- [noise, '0', add, '0']
- [split, '0', fft_low, '0']
- [split, '1', fft_high, '0']
- [target, '0', add, '1']
- [throttle, '0', dechirp, '1']
- [throttle, '0', target, '0']
metadata:
    file_format: 2
    grc_version: 3.11.0.0