79 lines
3.4 KiB
Python
79 lines
3.4 KiB
Python
from utils.data import Recording
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import numpy as np
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from utils.signal import block_generator
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import argparse
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mods = {
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"bpsk": {"num_bits_per_symbol": 1, "constellation_type": "psk"},
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"qpsk": {"num_bits_per_symbol": 2, "constellation_type": "psk"},
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"qam16": {"num_bits_per_symbol": 4, "constellation_type": "qam"},
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"qam64": {"num_bits_per_symbol": 6, "constellation_type": "qam"},
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}
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def generate_modulated_signals(output_dir):
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for modulation in ["bpsk", "qpsk", "qam16", "qam64"]:
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for snr in np.arange(-6, 13, 3):
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for i in range(100):
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recording_length = 1024
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beta = 0.3 # the rolloff factor, can be changed to add variety
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sps = 4 # samples per symbol, or the relative bandwidth of the digital signal. Can also be changed.
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# blocks don't directly take the string 'qpsk' so we use the dict 'mods' to get parameters
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constellation_type = mods[modulation]["constellation_type"]
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num_bits_per_symbol = mods[modulation]["num_bits_per_symbol"]
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# construct the digital modulation blocks with these parameters
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# we have bit source -> mapper -> upsampling -> pulse shaping
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bit_source = block_generator.RandomBinarySource()
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mapper = block_generator.Mapper(
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constellation_type=constellation_type,
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num_bits_per_symbol=num_bits_per_symbol,
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)
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upsampler = block_generator.Upsampling(factor=sps)
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pulse_shaping_filter = block_generator.RaisedCosineFilter(
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upsampling_factor=sps, beta=beta
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)
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pulse_shaping_filter.connect_input([upsampler])
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upsampler.connect_input([mapper])
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mapper.connect_input([bit_source])
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modulation_recording = pulse_shaping_filter.record(
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num_samples=recording_length
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)
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# add noise by calculating the power of the modulation recording and generating AWGN from the snr parameter
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signal_power = np.mean(np.abs(modulation_recording.data[0] ** 2))
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awgn_source = block_generator.AWGNSource(
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variance=(signal_power / 2) * (10 ** (((-1 * snr) / 20)))
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)
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noise = awgn_source.record(num_samples=recording_length)
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samples_with_noise = modulation_recording.data + noise.data
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output_recording = Recording(data=samples_with_noise)
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# add metadata for ML later
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output_recording.add_to_metadata(key="modulation", value=modulation)
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output_recording.add_to_metadata(key="snr", value=int(snr))
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output_recording.add_to_metadata(key="beta", value=beta)
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output_recording.add_to_metadata(key="sps", value=sps)
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# view if you want
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# output_recording.view()
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# save to file
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output_recording.to_npy() # optionally add path and filename parameters
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if __name__ == "__main__":
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p = argparse.ArgumentParser(description="Generate modulated signal .npy files")
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p.add_argument(
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"--output-dir",
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default=".",
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help="Folder where .npy files will be saved"
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)
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args = p.parse_args()
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generate_modulated_signals(args.output_dir)
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print("generated data to " + args.output_dir)
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