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RADE V2 prototyping#42

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dr-radev2
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RADE V2 prototyping#42
drowe67 wants to merge 235 commits intomainfrom
dr-radev2

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@drowe67 drowe67 commented Jan 17, 2025

Bandwidth/PAPR

Exploring ideas to improve 99% power bandwidth (spectral mask) from RADE V1. Just prototyping with "mixed rate" training and inference, i.e. no pilots or CP, genie phase.

  • Worked out how to put a BPF in training loop (conv1d with training disabled)
  • Take away that phase only (PAPR 0dB) works quite well
  • clip-BPF x 3 produces reasonable 99% power BW, 0dB PAPR, good loss
  • Doc ML EQ training and inference in README.md when we get to final V2 version. Just collect notes here in comments until then

Training:

python3 train.py --cuda-visible-devices 0 --sequence-length 400 --batch-size 512 --epochs 200 --lr 0.003 --lr-decay-factor 0.0001 ~/Downloads/tts_speech_16k_speexdsp.f32 250117_test --bottleneck 3 --h_file h_nc20_train_mpp.f32 --range_EbNo --plot_loss --auxdata --txbpf
Epoch 200 Loss 0.116

Testing:

./inference.sh 250117_test/checkpoints/checkpoint_epoch_200.pth wav/brian_g8sez.wav - --bottleneck 3 --auxdata --write_tx tx_bpf.f32 --write_latent z.f32 --txbpf
          Eb/No   C/No     SNR3k  Rb'    Eq     PAPR
Target..: 100.00  133.01   98.24  2000
Measured: 102.89          101.12       1243.47  0.00
loss: 0.121 BER: 0.000

octave:154> radae_plots; do_plots('z.f32','tx_bpf.f32')
bandwidth (Hz): 1255.813953 power/total_power: 0.990037

Red lines mark 99% power bandwidth:

Screenshot from 2025-01-22 07-13-34

ML EQ

Classical DSP:

python3 ml_eq.py --eq dsp --notrain --EbNodB 4 --phase_offset

MSE loss function:

python3 ml_eq.py --EbNodB 4 --phase_offset --lr 0.001 --epochs 100

Phase loss function:

python3 ml_eq.py --EbNodB 4 --phase_offset --lr 0.001 --epochs 100 --loss_phase

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drowe67 commented Feb 3, 2025

Frame 2 EQ examples

  1. Ideal (perfect EQ)

    python3 ml_eq.py --frame 2 --notrain --eq bypass --EbNodB 4
    <snip>
    EbNodB:  4.00 n_bits: 240000 n_errors: 3027 BER: 0.013
    
  2. Classical DSP lin:

    python3 ml_eq.py --eq dsp --notrain --EbNodB 4 --phase_offset --frame 2
    <snip>
    EbNodB:  4.00 n_bits: 240000 n_errors: 3921 BER: 0.016
    
  3. ML EQ (using MSE loss function):

    python3 ml_eq.py --frame 2 --lr 0.1 --epochs 100 --EbNodB 4 --phase_offset --n_syms 1000000 --batch_size 128
    <snip>
    EbNodB:  4.00 n_bits: 24000000 n_errors: 437933 BER: 0.018
    

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drowe67 commented Feb 4, 2025

ML waveform training

  1. Generate 10 hour complex h file:
    Fs=8000; Rs=50; Nc=20; multipath_samples('mpp', Fs, Rs, Nc, 10*60*60, 'h_nc20_train_mpp.c64',"",1);
    
  2. Training:
    python3 train.py --cuda-visible-devices 0 --sequence-length 400 --batch-size 512 --epochs 200 --lr 0.003 --lr-decay-factor 0.0001 ~/Downloads/tts_speech_16k_speexdsp.f32 250204_test --bottleneck 3 --h_file h_nc20_train_mpp.c64 --h_complex --range_EbNo --plot_loss --auxdata
    

drowe67 and others added 30 commits March 7, 2026 11:05
…demo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- radae/radae.py: add eoo_v2 property (two pend_cp symbols) with
  independent pilot_backoff_eoo_v2=-8dB giving peak<=1.0, RMS~0.56
- inference.py: add --end_of_over_v2 flag to append V2 EOO frame
- rx2.py: add _detect_eoo() with TEOO=0.7 and 2-consecutive-hit
  requirement; transitions to idle on detection
- CMakeLists.txt: add v2_eoo ctest (no noise, confirms EOO detected)

V1 EOO tests and all passing V2 tests remain green.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- inject_bad_pitch.py: new script to set feature[18] (pitch) to an
  extreme value in N frames of a features file
- CMakeLists.txt: rewrite pop1/pop2 tests to inject pitch=-3.0 into
  features_in before inference, transmit through the radio chain at
  high SNR, then check rx2.py's limit_pitch clamp suppresses pops
  (pop1) or allows them (pop2 with --nolimit_pitch)

Previously pop2 was flaky as it relied on the noisy MPP channel
randomly producing pitch values below the -1.4 threshold. Tests now
reliably produce 4 POPs through the full encode/decode chain.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- rx2.py: add IIR-smoothed pend symbol correlation for EOO detection
  (ALPHA_EOO=0.70, TEOO=0.42); reset smoother on re-sync and after EOO
- radae/radae.py: use 6 pend symbols for eoo_v2 (63ms overhead)
- inference.py: add --g_offset to shift MPP fade position for testing
- CMakeLists.txt: add EOO ctests: v2_eoo_awgn_low, v2_eoo_mpp_high,
  v2_eoo_mpp_low, v2_eoo_no_false_trigger_awgn, v2_eoo_no_false_trigger_mpp

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Compute snr_est_dB from the CP autocorrelation peak |Ry_smooth|:
  rho = SNR_bpf/(SNR_bpf+1)  ->  SNR_bpf = rho/(1-rho)

Subtract snr_offset_dB = 10*log10(3000/B_bpf) to convert from the
BPF noise bandwidth to SNR3k (C/No/3000), matching the Measured: line
from inference.py.  B_bpf is pre-computed in __init__ from model.w and
Nc.  Add --write_snr_est to log the per-symbol estimate to a .f32 file.

Add check_snr_est.py helper and two ctests (v2_snr_est_high/low) that
verify the estimator is within ±2 dB of the inference.py Measured SNR3k
at approximately +5 dB and -5 dB operating points.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…as ringing, and uses max of complex after HT. I'm assuming that peak of real signal is what matters to radio
test/eoo_detect_prob.sh: measures P(correct EOO detection) by stepping
through 2s segments of all.wav, one trial per segment. Reports detected/N.

test/eoo_false_prob.sh: measures false EOO trigger rate using full all.wav
per trial (so IIR smoother can build up). Reports avg time between false
triggers = (N * wav_dur) / total_false seconds.

Both scripts support --EbNodB, --channel awgn|mpp, --N options.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…elation

Replace the time-domain coherent correlation with a channel time-domain
sparsity metric. For each received symbol, estimate H[k] = Rx[k]/Pend[k]
at active subcarriers, IFFT to get the implied channel impulse response,
and measure the fraction of energy within the CP window (forward + mirror).

A true pend symbol gives H[k] = physical channel with energy concentrated
near tau=0 (sparsity ~0.95-0.97). A data symbol gives random phases across
subcarriers, spreading the IFFT energy uniformly (~0.50 mean). This makes
the metric immune to MPP phase cancellation that defeated the old coherent
approach (40% -> 100% detection at EbNodB=100 MPP).

Raise TEOO from 0.42 to 0.75 to match the new metric range. Update ctest
SNR levels and remove g_offset workarounds no longer needed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Add snr_est_test.sh to measure SNR estimator accuracy across a range
of EbNodB values for AWGN, MPG, and MPP channels.

Apply a linear correction (SNR_corr = 1.244*SNR_raw + 3.333) fitted
by least-squares over all three channels to reduce bias. Also switch
from Ry_max scalar to np.max(|Ry_smooth|) for the rho estimate, and
redirect rx2.py stdout prints to stderr.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Pass -l $wav to the decode step so x is derived from the input wav
file duration rather than estimated from rx.wav total length.  The
estimate was ~0.24s too long, giving V1 only ~0.26s of leading silence
to acquire sync.  With accurate timing V1 loss improves from 0.917 to
0.290.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
MPP fading channel consistently gives V1 loss ~0.415, just above the
previous 0.4 threshold.  Raise to 0.45 to give a small margin while
still catching gross failures (false sync etc).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…ise processing

rade2 uses pad 1 1 (1s pre + 1s post silence) vs rade1's pad 1 (1s post only),
so len_rade2 = x+2.5 (= len_rade + 1.0). Without a length limit, missed EOO
detection caused rx2 to decode up to 1.8s of hangover noise, inflating loss.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Copy ch channel simulation tool and mksine utility from codec2-dev into
radae/src, eliminating the need for a codec2-dev checkout to build and
run ctests.

New files in src/: ch.c, ch_fdmdv.c, ch_fdmdv.h (fdmdv_freq_shift_coh
extracted from cohpsk.c), comp.h, comp_prim.h, ht_coeff.h,
ssbfilt_coeff.h, debug_alloc.h (all from codec2-dev/src), mksine.c
(from codec2-dev/misc).

CMakeLists.txt: CODEC2_DEV_BUILD_DIR is now an empty optional cache
variable; all ctest references updated to use ${CMAKE_BINARY_DIR}/src/ch
and ${CMAKE_BINARY_DIR}/src/mksine.

Test scripts chirp_mpp.sh, ota_test_cal.sh, v2_acq.sh updated to use
RADAE_BUILD_DIR instead of CODEC2_DEV_BUILD_DIR.

All 84 ctests pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
ch and mksine are now built within radae, so codec2-dev is no longer
needed. Remove CODEC2_DEV PATH entries from ota_test.sh, evaluate.sh,
and analog_bbfm.sh, replacing with build/src. Remove HackRF support
(tlininterp dependency) from ota_test.sh. Fix octave spectrogram to
use scripts already present in radae root. Remove codec2-dev install
step from GitHub Actions workflow.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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