SDR Wideband Suite

Go-based SDR analysis engine and live spectrum/waterfall UI, evolved from the original sdr-visual-suite into a more scalable foundation for wideband monitoring, candidate-driven refinement, classification, and demod/recording.

Features

• Live spectrum + waterfall web UI (WebSocket streaming)
• Event timeline view (time vs frequency) + detail drawer
• Live signal list + classifier insights
• Runtime UI controls: center, span, sample rate, tuner bandwidth, analysis FFT size, gain, AGC, DC block, IQ balance, detector settings
• Optional GPU FFT (cuFFT) + /api/gpu
• IQ/audio recording + recordings list
• Live demod endpoint + WebSocket live-listen audio
• WFM stereo + RDS baseband
• Mock mode for testing without hardware
• Phase-1 architecture foundation complete: explicit pipeline/surveillance/refinement/resources config model plus candidate/refinement/admission scaffolding

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Requirements

Core

• Go 1.22 (see go.mod)

Optional (real device)

• SDRplay API (sdrplay_api.h + library)

Optional (GPU)

• CUDA toolkit (cuFFT)
• nvcc for kernel build (Linux) or build-gpudemod-dll.ps1 (Windows)

Windows build prerequisites (real device + GPU)

• MSYS2 MinGW64 (C:\msys64\mingw64\bin\gcc.exe / g++.exe) for CGO
• SDRplay API installed (default path in scripts)
• CUDA toolkit (default paths in scripts)

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Quick Start (Mock Mode)

# From repo root

go run ./cmd/sdrd --mock

Open http://localhost:8080.

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Configuration

Edit config.yaml (autosave goes to config.autosave.yaml).

Legacy-compatible core fields

• center_hz, sample_rate, fft_size, gain_db, tuner_bw_khz
• use_gpu_fft, agc, dc_block, iq_balance
• detector.*
• recorder.*
• decoder.*

Phase-1 pipeline fields

• pipeline.mode -- operating mode label (legacy, wideband-balanced, ...)
• pipeline.profile -- last applied operating profile name (if any)
• pipeline.goals.* -- declarative target/intent layer for future autonomous operation
  • intent
  • monitor_start_hz / monitor_end_hz / monitor_span_hz
  • signal_priorities
  • auto_record_classes
  • auto_decode_classes
• surveillance.analysis_fft_size -- analysis FFT size used by the surveillance layer
• surveillance.frame_rate -- surveillance cadence target
• surveillance.strategy -- single-resolution or multi-resolution
• surveillance.display_bins -- preferred presentation density for clients/UI
• surveillance.display_fps -- preferred presentation cadence for clients/UI
• refinement.enabled -- enables explicit candidate refinement stage
• refinement.max_concurrent -- refinement budget hint
• refinement.detail_fft_size -- FFT size for refinement/detail path (defaults to surveillance analysis FFT)
• refinement.min_candidate_snr_db -- floor for future scheduling decisions
• refinement.min_span_hz / refinement.max_span_hz -- clamp refinement window span (0 = no clamp)
• refinement.auto_span -- use mod-type heuristics when candidate bandwidth is missing/odd
• resources.prefer_gpu -- GPU preference hint

Operating profiles (wideband)

• wideband-balanced: multi-resolution, 4096 surveillance/detail FFT, refinement span 4000-200000 Hz
• wideband-aggressive: multi-resolution, 8192 surveillance/detail FFT, refinement span 6000-250000 Hz
• archive: record-forward bias, higher record/decode budgets, 4096 detail FFT
• digital-hunting: digital-first priorities and decode bias
• resources.max_refinement_jobs -- processing budget hint
• resources.max_recording_streams -- recording/streaming budget hint
• resources.max_decode_jobs -- decode budget hint
• resources.decision_hold_ms -- baseline hold time for queue slots before churn (arbitration scales per profile/strategy and tags hold reasons in debug snapshots)
• profiles[] -- named operating profiles/intent metadata

Phase 1 stays backward compatible, but the config model now reflects the intended separation between:

• acquisition
• surveillance analysis
• local refinement
• resource policy
• presentation
• operator goals / future autonomous intent

Refinement plans now rank candidates, while a shared arbitration step admits refinement/record/decode work based on budgets and hold policy. Arbitration reasons are normalized:

• refinement:* for work item lifecycle (planned/admitted/running/completed/drop/skip)
• admission:* for refinement admission outcomes
• decision:* for record/decode decisions
• queue:* when record/decode is deferred by budget Hold policy reasons are surfaced as profile:* / strategy:* tokens in hold_source.

Phase-1 scope stops at consistent policy surfaces, ranking/admission scaffolding, and debug visibility. Phase 2+ adds a true multi-resolution surveillance engine and scheduler/intent overrides that can re-balance budgets automatically.

The long-term target is that you describe what the system should do (for example broad-span monitoring intent, preferred signal families, auto-record/decode priorities), while the engine decides how to allocate surveillance, refinement and decoding budgets.

CFAR modes: OFF, CA, OS, GOSCA, CASO

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Build & Run (Windows)

Mock / No SDRplay

go build ./cmd/sdrd
.\sdrd.exe --mock

SDRplay (Real Device)

$env:CGO_CFLAGS='-IC:\Program Files\SDRplay\API\inc'
$env:CGO_LDFLAGS='-LC:\Program Files\SDRplay\API\x64 -lsdrplay_api'

go build -tags sdrplay ./cmd/sdrd
.\sdrd.exe -config config.yaml

Windows (GPU + SDRplay) -- recommended path

powershell -ExecutionPolicy Bypass -File .\build-cuda-windows.ps1
powershell -ExecutionPolicy Bypass -File .\build-sdrplay.ps1

This path:

• Builds gpudemod_kernels.dll (MSVC/nvcc)
• Builds Go app with MinGW64 CGO + tags sdrplay,cufft
• Copies CUDA runtime DLLs next to sdrd.exe

Notes:

• build-sdrplay.ps1 expects MinGW at C:\msys64\mingw64\bin
• CUDA DLLs are copied if found (see script for exact paths)
• Override the GPU DLL path with GPUMOD_DLL=C:\path\to\gpudemod_kernels.dll

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Build & Run (Linux)

SDRplay (Real Device)

export CGO_CFLAGS='-I/opt/sdrplay_api/include'
export CGO_LDFLAGS='-L/opt/sdrplay_api/lib -lsdrplay_api'

go build -tags sdrplay ./cmd/sdrd
./cmd/sdrd/sdrd -config config.yaml

CUDA kernel build (GPU demod)

./build-cuda-linux.sh

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APIs

Config

• GET /api/config
• POST /api/config
• POST /api/sdr/settings
• GET /api/gpu
• GET /api/pipeline/policy
• GET /api/pipeline/recommendations
• GET /api/refinement -> latest refinement plan/windows snapshot (includes window_stats, levels, request/context/work_items, plus arbitration with budgets/hold policy/refinement admission/queue/decision summary)

Signals / Events

• GET /api/signals -> current live signals
• GET /api/events?limit=&since= -> recent events

Recordings

• GET /api/recordings
• GET /api/recordings/:id (meta.json)
• GET /api/recordings/:id/iq
• GET /api/recordings/:id/audio
• GET /api/recordings/:id/decode?mode=FT8|WSPR|DMR|D-STAR|FSK|PSK

Live Demod / Listen

• GET /api/demod?freq=...&bw=...&mode=...&sec=... -> audio/wav
• WS /ws/audio?freq=...&bw=...&mode=... -> live PCM audio stream

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Decoder Tools

Put external decoder binaries/scripts under tools/ and configure decoder.* in config.yaml. Placeholders: {iq}, {audio}, {sr}. See tools/README.md for examples.

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Tests

go test ./...

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Troubleshooting

• sdrplay support not built -> rebuild with -tags sdrplay.
• SDRplay library not found -> check CGO_CFLAGS / CGO_LDFLAGS.
• GPU demod not loading -> verify gpudemod_kernels.dll / cudart64_13.dll next to sdrd.exe (Windows).
• Use --mock to run without hardware.