Ryan Malloy
493c21c511
Implement the transmit/generate side as streaming GNU Radio blocks, complementing the existing receive chain. Each block maps to a physical instrument on CuriousMarc's Keysight bench: pcm_frame_source - PCM bit stream generator (sync_block + FrameSourceEngine) nrz_encoder - bits to NRZ waveform (+1/-1) with upsampling bpsk_subcarrier_mod - NRZ x cos(1.024 MHz) BPSK modulator fm_voice_subcarrier_mod - 1.25 MHz FM test tone source pm_mod - phase modulator: exp(j * deviation * input) usb_signal_source - convenience wrapper wiring all blocks together Includes GRC YAML definitions for all blocks under [Apollo USB] category, 49 new tests (271 total, all passing), and a loopback test that validates the full TX->RX round trip including frame recovery with 30 dB AWGN.
53 lines
1.2 KiB
YAML
53 lines
1.2 KiB
YAML
id: apollo_nrz_encoder
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label: Apollo NRZ Encoder
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category: '[Apollo USB]'
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flags: [python]
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parameters:
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- id: bit_rate
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label: Bit Rate (bps)
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dtype: int
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default: '51200'
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options: ['51200', '1600']
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option_labels: ['High (51.2 kbps)', 'Low (1.6 kbps)']
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- id: sample_rate
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label: Sample Rate
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dtype: real
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default: '5120000'
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inputs:
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- label: in
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domain: stream
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dtype: byte
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outputs:
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- label: out
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domain: stream
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dtype: float
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templates:
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imports: from apollo.nrz_encoder import nrz_encoder
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make: apollo.nrz_encoder.nrz_encoder(bit_rate=${bit_rate}, sample_rate=${sample_rate})
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documentation: |-
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Apollo NRZ Encoder
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Converts a stream of byte values (0 or 1) to a Non-Return-to-Zero
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baseband waveform at the specified sample rate.
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Mapping:
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bit 1 -> +1.0 (held for bit period)
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bit 0 -> -1.0 (held for bit period)
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Each bit value is upsampled by samples_per_bit = sample_rate / bit_rate.
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At the default high rate (51.2 kbps, 5.12 MHz), this is 100 samples
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per bit. At low rate (1.6 kbps), it is 3200 samples per bit.
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This is the transmit-side counterpart to the slicer in bpsk_demod.
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Parameters:
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bit_rate: PCM bit rate in bps (51200 high, 1600 low)
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sample_rate: Output sample rate in Hz (default 5.12 MHz)
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file_format: 1
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