Ryan Malloy
0ee7ff0ad7
Complete signal processing pipeline from complex baseband to decoded PCM telemetry, verified against the 1965 NAA Study Guide (A-624): Core demod (Phase 1): - PM demodulator with carrier PLL recovery - 1.024 MHz subcarrier extractor (bandpass + downconvert) - BPSK demodulator with Costas loop + symbol sync - Convenience hier_block2 combining subcarrier + BPSK PCM frame processing (Phase 2): - 32-bit frame sync with Hamming distance correlator - SEARCH/VERIFY/LOCKED state machine, complement-on-odd handling - Frame demultiplexer (128-word, A/D voltage scaling) - AGC downlink decoder (15-bit word reassembly from DNTM1/DNTM2) Voice and analog (Phase 3): - 1.25 MHz FM voice subcarrier demod to 8 kHz audio - SCO demodulator for 9 analog sensor channels (14.5-165 kHz) Virtual AGC integration (Phase 4): - TCP bridge client with auto-reconnect and channel filtering - DSKY uplink encoder (VERB/NOUN/DATA command sequences) Top-level receiver (Phase 5): - usb_downlink_receiver hier_block2: one block, complex in, PDUs out - 14 GRC block YAML definitions for GNU Radio Companion - Example scripts for signal analysis and full-chain demo Infrastructure: - constants.py with all timing/frequency/frame parameters - protocol.py for sync word + AGC packet encode/decode - Synthetic USB signal generator for testing - 222 tests passing, ruff lint clean
51 lines
1.0 KiB
YAML
51 lines
1.0 KiB
YAML
id: apollo_bpsk_demod
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label: Apollo BPSK Demod
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category: '[Apollo USB]'
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flags: [python]
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parameters:
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- id: symbol_rate
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label: Symbol Rate (bps)
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dtype: real
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default: '51200'
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- id: sample_rate
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label: Sample Rate (Hz)
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dtype: real
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default: '5120000'
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- id: loop_bw
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label: Loop Bandwidth
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dtype: real
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default: '0.045'
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inputs:
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- label: in
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domain: stream
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dtype: complex
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outputs:
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- label: out
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domain: stream
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dtype: byte
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templates:
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imports: from apollo import bpsk_demod
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make: >-
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apollo.bpsk_demod.bpsk_demod(
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symbol_rate=${symbol_rate},
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sample_rate=${sample_rate},
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loop_bw=${loop_bw})
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documentation: |-
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Apollo BPSK Demodulator
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Recovers NRZ bit stream from a BPSK-modulated subcarrier at baseband.
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Uses Costas loop for 180-degree phase ambiguity resolution and
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integrate-and-dump for symbol timing.
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Parameters:
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symbol_rate: Bit rate in bps (51200 high, 1600 low)
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sample_rate: Input sample rate in Hz
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loop_bw: Carrier/timing recovery loop bandwidth
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file_format: 1
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