R4W - Rust for Waveforms

What is R4W?

A complete platform for developing, testing, and deploying Software Defined Radio waveforms in Rust.

• 84,467 lines of production code
• 66,572 lines of Rust (527 tests)
• 38+ waveforms implemented
• 6,324 lines of Coq formal verification

Platform Architecture

┌─────────────────────────────────────────────────────┐
│                    Applications                     │
│         (r4w-explorer, r4w CLI, r4w-web)            │
├─────────────────────────────────────────────────────┤
│    Waveforms (38+)          │     Plugins (.so)     │
│  LoRa, PSK, QAM, FSK, OFDM  │  Dynamic loading      │
│  SINCGARS, HAVEQUICK, P25   │  Hot reload           │
├─────────────────────────────────────────────────────┤
│                    Core DSP                         │
│     Chirp, FFT, Filters, FEC, Timing, RT Buffers    │
├─────────────────────────────────────────────────────┤
│    Hardware Abstraction     │    Waveform Sandbox   │
│  USRP, RTL-SDR, Simulator   │  8 isolation levels   │
│  Xilinx Zynq, Lattice FPGA  │  Containers, VMs      │
└─────────────────────────────────────────────────────┘

The R4W Explorer

Interactive GUI for learning and experimenting with waveforms.

Educational Overview

Each waveform includes:

• What is SDR? - Introduction to concepts
• I/Q Samples - Complex number representation
• Modulation theory - How bits become signals
• Processing pipeline - TX and RX data flow

Waveform Lab

Experiment with modulation parameters in real-time.

Interactive Features

• Bit sequences - Test custom payloads
• Channel simulation - Add AWGN noise
• Time domain - View I/Q waveforms
• Constellation - See symbol positions
• BER measurement - Real-time error rates

Real-Time Streaming

Live signal visualization with multiple views.

Streaming Views

Four synchronized visualizations:

Plus spectrum analyzer with power measurements.

Code Explorer

Learn by reading the actual Rust implementation.

Educational Code

• Syntax highlighting for Rust
• Expandable explanations for each function
• Complexity ratings (1-5 stars)
• Real production code - not simplified examples

Performance Benchmarks

Compare sequential vs parallel processing.

Benchmark Results

SIMD: SSE4.2, AVX2 when available.

LoRa Chirp Signals

Visualize Chirp Spread Spectrum modulation.

Understanding Chirps

• I/Q components - Real (blue) and Imaginary (red)
• Instantaneous frequency - Linear sweep
• Symbol encoding - Cyclic shift of chirp
• SF7 @ 125 kHz - 128 chips per symbol

38+ Waveforms

Comprehensive waveform library.

Waveform Categories

Full TX/RX Pipeline

Complete modulation to demodulation visualization.

Pipeline Stages

Modulation → Channel → Demodulation
    │           │           │
    ▼           ▼           ▼
 Bit-to-    Add AWGN    Sample
 Symbol      Noise     Processing
    │           │           │
    ▼           ▼           ▼
 Sample     Apply       Bit
Generation  Fading    Recovery

BER: 0.00e0 (Perfect) at 40 dB SNR

Spectrum Analyzer

Frequency domain analysis.

Spectrum Features

• FFT-based analysis (32-8192 points)
• Magnitude and Phase display
• Log scale (dB) option
• Window position scrubbing
• Frequency resolution display

Zigbee example: O-QPSK with half-sine pulse shaping.

Constellation Diagrams

I/Q signal visualization.

Constellation Features

• Real-time point plotting
• Trajectory visualization
• Point count control (10-1000)
• Educational notes for each modulation type

AM: Amplitude varies along I-axis, phase constant.

Interactive Tutorial

Web-based learning path.

Tutorial Curriculum

Complexity levels L1 (beginner) to L5 (advanced).

FPGA Acceleration

Hardware acceleration for real-time processing.

Zynq IP Cores

vivado/ip/
├── r4w_fft/         # 1024-pt FFT (~15k LUTs)
├── r4w_fir/         # 256-tap FIR (~8k LUTs)
├── r4w_chirp_gen/   # LoRa chirp generator
├── r4w_chirp_corr/  # Chirp correlator
├── r4w_nco/         # NCO (~1.5k LUTs)
└── r4w_dma/         # DMA controller

Security: Waveform Isolation

8 levels of sandboxing for untrusted waveforms.

Formal Verification

6,324 lines of Coq proofs.

• FFT correctness - Output matches DFT definition
• Chirp properties - Energy preservation
• Timing guarantees - RT scheduler proofs

Performance vs GNU Radio

Zero-copy lock-free buffers, no Python overhead.

Real-Time Validation

Getting Started

# Clone and build
git clone https://github.com/joemooney/r4w
cd r4w && cargo build --release

# Run the explorer
cargo run --bin r4w-explorer

# Run tests (527 tests)
cargo test

# Generate documentation
cargo doc --open

Quick Commands

Resources

• GitHub: github.com/joemooney/r4w
• Documentation: cargo doc --open
• Workshop: workshop/ directory
• Tutorial: tutorial/index.html

Summary

R4W: Production-ready SDR in Rust

Questions?

R4W - Rust for Waveforms

github.com/joemooney/r4w