Coherent Human Channel Imaging (CHCI) Domain Model

Domain-Driven Design Specification

Ubiquitous Language

Term	Definition
Coherent Human Channel Imaging (CHCI)	A purpose-built RF sensing protocol that uses phase-locked sounding, multi-band fusion, and cognitive waveform adaptation to reconstruct human body surfaces and physiological motion at sub-millimeter resolution
Sounding Frame	A deterministic OFDM transmission (NDP or custom burst) with known pilot structure, transmitted at fixed cadence for channel measurement — as opposed to passive CSI extracted from data traffic
Phase Coherence	The property of multiple radio nodes sharing a common phase reference, enabling complex-valued channel measurements without per-node LO drift correction
Reference Clock	A shared oscillator (TCXO + PLL) distributed to all CHCI nodes via coaxial cable, providing both 40 MHz timing reference and in-band phase reference signal
Cognitive Waveform	A sounding waveform whose parameters (cadence, bandwidth, band selection, power, subcarrier subset) adapt in real-time based on the current scene state inferred from the body model
Diffraction Tomography	Coherent reconstruction of body surface geometry from complex-valued channel responses across multiple node pairs and frequency bands — produces surface contours rather than volumetric opacity
Sensing Mode	One of six operational states (IDLE, ALERT, ACTIVE, VITAL, GESTURE, SLEEP) that determine waveform parameters and processing pipeline configuration
Micro-Burst	A very short (4–20 μs) deterministic OFDM symbol transmitted at high cadence (1–5 kHz) for maximizing Doppler resolution without full 802.11 frame overhead
Multi-Band Fusion	Simultaneous sounding at 2.4 GHz and 5 GHz (optionally 6 GHz), fused as projections of the same latent motion field using body model priors as constraints
Displacement Floor	The minimum detectable surface displacement at a given range, determined by phase noise, coherent averaging depth, and antenna count: δ_min = λ/(4π) × σ_φ/√(N_ant × N_avg)
Channel Contrast	The ratio of complex channel response with human present to the empty-room reference response — the input to diffraction tomography
Coherence Delta	The change in phase coherence metric between consecutive observation windows — the trigger signal for cognitive waveform transitions
NDP	Null Data PPDU — an 802.11bf-standard sounding frame containing only preamble and training fields, no data payload
Sensing Availability Window (SAW)	An 802.11bf-defined time interval during which NDP sounding exchanges are permitted between sensing initiator and responder
Body Model Prior	Geometric constraints derived from known human body dimensions (segment lengths, joint angle limits) used to regularize cross-band fusion and tomographic reconstruction
Phase Reference Signal	A continuous-wave tone at the operating band center frequency, distributed alongside the 40 MHz clock, enabling all nodes to measure and compensate residual phase offset

Bounded Contexts

1. Waveform Generation Context

Responsibility: Generating, scheduling, and transmitting deterministic sounding waveforms across all CHCI nodes.

┌──────────────────────────────────────────────────────────────┐
│              Waveform Generation Context                      │
├──────────────────────────────────────────────────────────────┤
│                                                                │
│  ┌───────────────┐    ┌───────────────┐    ┌──────────────┐  │
│  │ NDP Sounding  │    │ Micro-Burst   │    │ Chirp        │  │
│  │ Generator     │    │ Generator     │    │ Generator    │  │
│  │ (802.11bf)    │    │ (Custom OFDM) │    │ (Multi-BW)   │  │
│  └───────┬───────┘    └───────┬───────┘    └──────┬───────┘  │
│          │                    │                    │          │
│          └────────────┬───────┴────────────────────┘          │
│                       ▼                                       │
│            ┌──────────────────┐                               │
│            │ Sounding         │                               │
│            │ Scheduler        │ ← Cadence, band, power from  │
│            │ (Aggregate Root) │   Cognitive Engine             │
│            └────────┬─────────┘                               │
│                     │                                         │
│          ┌──────────┴──────────┐                             │
│          ▼                     ▼                             │
│  ┌──────────────┐    ┌──────────────┐                       │
│  │ TX Chain     │    │ TX Chain     │                       │
│  │ (2.4 GHz)   │    │ (5 GHz)      │                       │
│  └──────────────┘    └──────────────┘                       │
│                                                               │
│  Events emitted:                                             │
│    SoundingFrameTransmitted { band, timestamp, seq_id }      │
│    BurstSequenceCompleted { burst_count, duration }           │
│    WaveformConfigChanged { old_mode, new_mode }               │
│                                                               │
└──────────────────────────────────────────────────────────────┘

Aggregates:

SoundingScheduler (Aggregate Root) — Orchestrates sounding frame transmission across nodes and bands according to the current waveform configuration

Entities:

SoundingFrame — A single NDP or micro-burst transmission with sequence ID, band, timestamp, and pilot structure
BurstSequence — An ordered set of micro-bursts within one observation window, used for coherent Doppler integration
WaveformConfig — The current waveform parameter set (cadence, bandwidth, band selection, power level, subcarrier mask)

Value Objects:

SoundingCadence — Transmission rate in Hz (1–5000), constrained by regulatory duty cycle limits
BandSelection — Set of active bands {2.4 GHz, 5 GHz, 6 GHz} for current mode
SubcarrierMask — Bit vector selecting active subcarriers for focused sensing (vital mode uses optimal subset)
BurstDuration — Single burst length in microseconds (4–20 μs)
DutyCycle — Computed duty cycle percentage, must not exceed regulatory limit (ETSI: 10 ms max burst)

Domain Services:

RegulatoryComplianceChecker — Validates that any waveform configuration satisfies FCC Part 15.247 and ETSI EN 300 328 constraints before applying
BandCoordinator — Manages time-division or simultaneous multi-band sounding to avoid self-interference

2. Clock Synchronization Context

Responsibility: Distributing and maintaining phase-coherent timing across all CHCI nodes in the sensing mesh.

┌──────────────────────────────────────────────────────────────┐
│              Clock Synchronization Context                    │
├──────────────────────────────────────────────────────────────┤
│                                                                │
│  ┌───────────────┐                                           │
│  │ Reference      │                                           │
│  │ Clock Module   │ ← TCXO (40 MHz, ±0.5 ppm)               │
│  │ (Aggregate     │                                           │
│  │  Root)         │                                           │
│  └───────┬────────┘                                           │
│          │                                                    │
│  ┌───────┴────────┐                                           │
│  │ PLL Synthesizer│ ← SI5351A: generates 40 MHz clock        │
│  │                │   + 2.4/5 GHz CW phase reference         │
│  └───────┬────────┘                                           │
│          │                                                    │
│    ┌─────┼─────────────────┐                                 │
│    ▼     ▼                 ▼                                 │
│  ┌─────┐ ┌─────┐        ┌─────┐                            │
│  │Node1│ │Node2│  ...   │NodeN│                            │
│  │Phase│ │Phase│        │Phase│                            │
│  │Lock │ │Lock │        │Lock │                            │
│  └──┬──┘ └──┬──┘        └──┬──┘                            │
│     │       │              │                                 │
│     └───────┼──────────────┘                                 │
│             ▼                                                │
│  ┌──────────────────┐                                        │
│  │ Phase Calibration │ ← Measures residual offset            │
│  │ Service           │   per node at startup                 │
│  └──────────────────┘                                        │
│                                                               │
│  Events emitted:                                             │
│    ClockLockAcquired { node_id, offset_ppm }                 │
│    PhaseDriftDetected { node_id, drift_deg_per_min }         │
│    CalibrationCompleted { residual_offsets: Vec<f64> }        │
│                                                               │
└──────────────────────────────────────────────────────────────┘

Aggregates:

ReferenceClockModule (Aggregate Root) — The single source of timing truth for the entire CHCI mesh

Entities:

NodePhaseLock — Per-node state tracking lock status, residual offset, and drift rate
CalibrationSession — A timed procedure that measures and records per-node phase offsets under static conditions

Value Objects:

PhaseOffset — Residual phase offset in degrees after clock distribution, per node per subcarrier
DriftRate — Phase drift in degrees per minute, must remain below threshold (0.05°/min for heartbeat sensing)
LockStatus — Enum {Acquiring, Locked, Drifting, Lost} indicating current synchronization state

Domain Services:

PhaseCalibrationService — Runs startup and periodic calibration routines; replaces statistical LO estimation in current phase_align.rs
DriftMonitor — Continuous background service that detects when any node exceeds drift threshold and triggers recalibration

Invariants:

All nodes must achieve Locked status before CHCI sensing begins
Phase variance per subcarrier must remain ≤ 0.5° RMS over any 10-minute window
If any node transitions to Lost, system falls back to statistical phase correction (legacy mode)

3. Coherent Signal Processing Context

Responsibility: Processing raw coherent CSI into body-surface representations using diffraction tomography and multi-band fusion.

┌──────────────────────────────────────────────────────────────────┐
│              Coherent Signal Processing Context                   │
├──────────────────────────────────────────────────────────────────┤
│                                                                    │
│  ┌───────────────┐    ┌───────────────┐    ┌──────────────────┐  │
│  │ Coherent CSI  │    │ Reference     │    │ Calibration      │  │
│  │ Stream        │    │ Channel       │    │ Store            │  │
│  │ (per node     │    │ (empty room)  │    │ (per deployment) │  │
│  │  per band)    │    │               │    │                  │  │
│  └───────┬───────┘    └───────┬───────┘    └────────┬─────────┘  │
│          │                    │                     │            │
│          └────────────┬───────┴─────────────────────┘            │
│                       ▼                                           │
│           ┌───────────────────────┐                              │
│           │ Channel Contrast      │                              │
│           │ Computer              │                              │
│           │ H_c = H_meas / H_ref  │                              │
│           └───────────┬───────────┘                              │
│                       │                                           │
│            ┌──────────┴──────────┐                               │
│            ▼                     ▼                               │
│  ┌──────────────────┐  ┌──────────────────┐                    │
│  │ Diffraction      │  │ Multi-Band       │                    │
│  │ Tomography       │  │ Coherent Fusion  │                    │
│  │ Engine           │  │                  │                    │
│  │ (Aggregate Root) │  │ Body model priors │                    │
│  │                  │  │ as soft           │                    │
│  │ Complex          │  │ constraints       │                    │
│  │ permittivity     │  │                  │                    │
│  │ contrast per     │  │ Cross-band phase  │                    │
│  │ voxel            │  │ alignment         │                    │
│  └────────┬─────────┘  └────────┬─────────┘                    │
│           │                     │                               │
│           └──────────┬──────────┘                               │
│                      ▼                                          │
│           ┌──────────────────┐                                  │
│           │ Body Surface     │──▶ DensePose UV Mapping          │
│           │ Reconstruction   │                                  │
│           └──────────────────┘                                  │
│                                                                  │
│  Events emitted:                                                │
│    VoxelGridUpdated { grid_dims, resolution_cm, timestamp }      │
│    BodySurfaceReconstructed { n_vertices, confidence }           │
│    CoherenceDegradation { node_id, band, severity }              │
│                                                                  │
└──────────────────────────────────────────────────────────────────┘

Aggregates:

DiffractionTomographyEngine (Aggregate Root) — Reconstructs 3D body surface geometry from coherent channel contrast measurements across all node pairs and frequency bands

Entities:

CoherentCsiFrame — A single coherent channel measurement: complex-valued H(f) per subcarrier, with phase-lock metadata, node ID, band, sequence ID, and timestamp
ReferenceChannel — The empty-room complex channel response per link per band, used as the denominator in channel contrast computation
VoxelGrid — 3D grid of complex permittivity contrast values, the output of diffraction tomography
BodySurface — Extracted iso-surface from voxel grid, represented as triangulated mesh or point cloud

Value Objects:

ChannelContrast — Complex ratio H_measured/H_reference per subcarrier per link — the fundamental input to tomography
SubcarrierResponse — Complex-valued (amplitude + phase) channel response at a single subcarrier frequency
VoxelCoordinate — (x, y, z) position in room coordinate frame with associated complex permittivity value
SurfaceNormal — Orientation vector at each surface vertex, derived from permittivity gradient
CoherenceMetric — Complex-valued coherence score (magnitude + phase) replacing the current real-valued Z-score

Domain Services:

ChannelContrastComputer — Divides measured channel by reference to isolate human-induced perturbation
MultiBandFuser — Aligns phase across bands using body model priors and combines into unified spectral response
SurfaceExtractor — Applies marching cubes or similar iso-surface algorithm to permittivity contrast grid

RuVector Integration:

ruvector-attention → Cross-band attention weights for frequency fusion (extends CrossViewpointAttention)
ruvector-solver → Sparse reconstruction for under-determined tomographic inversions
ruvector-temporal-tensor → Temporal coherence of surface reconstructions across frames

4. Cognitive Waveform Context

Responsibility: Adapting the sensing waveform in real-time based on scene state, optimizing the tradeoff between sensing fidelity and power consumption.

┌──────────────────────────────────────────────────────────────┐
│              Cognitive Waveform Context                       │
├──────────────────────────────────────────────────────────────┤
│                                                                │
│  ┌───────────────────────────────────────────────────────┐   │
│  │              Scene State Observer                       │   │
│  │                                                         │   │
│  │  Body Model ──▶ ┌──────────────┐                       │   │
│  │                  │ Coherence    │                       │   │
│  │  Coherence   ──▶│ Delta        │──▶ Mode Transition    │   │
│  │  Metrics        │ Analyzer     │    Signal              │   │
│  │                  └──────────────┘                       │   │
│  │  Motion      ──▶                                       │   │
│  │  Classifier                                            │   │
│  └───────────────────────────────────────────────────────┘   │
│                       │                                       │
│                       ▼                                       │
│           ┌───────────────────────┐                           │
│           │ Sensing Mode          │                           │
│           │ State Machine         │                           │
│           │ (Aggregate Root)      │                           │
│           │                       │                           │
│           │ IDLE ──▶ ALERT ──▶ ACTIVE                        │
│           │                   ╱  │  ╲                         │
│           │              VITAL  GESTURE  SLEEP               │
│           │                                                   │
│           └───────────┬───────────┘                           │
│                       │                                       │
│                       ▼                                       │
│           ┌───────────────────────┐                           │
│           │ Waveform Parameter    │                           │
│           │ Computer              │                           │
│           │                       │──▶ WaveformConfig          │
│           │ Mode → {cadence,      │    (to Waveform            │
│           │   bandwidth, bands,   │     Generation Context)    │
│           │   power, subcarriers} │                           │
│           └───────────────────────┘                           │
│                                                               │
│  Events emitted:                                             │
│    SensingModeChanged { from, to, trigger_reason }            │
│    PowerBudgetAdjusted { new_budget_mw, mode }                │
│    SubcarrierSubsetOptimized { selected: Vec<u16>, criterion }│
│                                                               │
└──────────────────────────────────────────────────────────────┘

Aggregates:

SensingModeStateMachine (Aggregate Root) — Manages transitions between six sensing modes based on coherence delta, motion classification, and body model state

Entities:

SensingMode — One of {IDLE, ALERT, ACTIVE, VITAL, GESTURE, SLEEP} with associated waveform parameter set
ModeTransition — A state change event with trigger reason, timestamp, and hysteresis counter
PowerBudget — Per-mode power allocation constraining cadence and TX power

Value Objects:

CoherenceDelta — Magnitude of coherence change between consecutive observation windows — the primary mode transition trigger
MotionClassification — Enum {Static, Breathing, Walking, Gesturing, Falling} derived from micro-Doppler signature
ModeHysteresis — Counter preventing rapid mode oscillation: requires N consecutive trigger events before transition (default N=3)
OptimalSubcarrierSet — The subset of subcarriers with highest SNR for vital sign extraction, computed from recent channel statistics

Domain Services:

SceneStateObserver — Fuses body model output, coherence metrics, and motion classifier into a unified scene state descriptor
ModeTransitionEvaluator — Applies hysteresis and priority rules to determine if a mode change should occur
SubcarrierSelector — Identifies optimal subcarrier subset for vital mode using Fisher information criterion or SNR ranking
PowerManager — Computes TX power and duty cycle to stay within regulatory and battery constraints per mode

Invariants:

IDLE mode must be entered after 30 seconds of no detection (configurable)
Mode transitions must satisfy hysteresis: ≥3 consecutive trigger events
Power budget must never exceed regulatory limit (20 dBm EIRP at 2.4 GHz)
Subcarrier subset in VITAL mode must include ≥16 subcarriers for statistical reliability

5. Displacement Measurement Context

Responsibility: Extracting sub-millimeter physiological displacement (breathing, heartbeat, tremor) from coherent phase time series.

┌──────────────────────────────────────────────────────────────┐
│              Displacement Measurement Context                 │
├──────────────────────────────────────────────────────────────┤
│                                                                │
│  ┌──────────────┐                                            │
│  │ Phase Time    │ ← Coherent CSI phase per subcarrier       │
│  │ Series Buffer │   per link, at sounding cadence           │
│  └──────┬───────┘                                            │
│         │                                                     │
│         ▼                                                     │
│  ┌──────────────────┐                                        │
│  │ Phase-to-         │                                        │
│  │ Displacement      │                                        │
│  │ Converter         │                                        │
│  │ δ = λΔφ / (4π)    │                                        │
│  └──────┬────────────┘                                        │
│         │                                                     │
│  ┌──────┴──────────────────────────┐                         │
│  │                                  │                         │
│  ▼                                  ▼                         │
│  ┌──────────────────┐  ┌──────────────────┐                 │
│  │ Respiratory       │  │ Cardiac          │                 │
│  │ Analyzer          │  │ Analyzer         │                 │
│  │ (Aggregate Root)  │  │                  │                 │
│  │                   │  │ Bandpass:        │                 │
│  │ Bandpass:         │  │ 0.8–3.0 Hz      │                 │
│  │ 0.1–0.6 Hz       │  │ (48–180 BPM)    │                 │
│  │ (6–36 BPM)       │  │                  │                 │
│  │                   │  │ Harmonic cancel  │                 │
│  │ Amplitude: 4–12mm │  │ (remove respir.  │                 │
│  │                   │  │  harmonics)      │                 │
│  └────────┬──────────┘  │                  │                 │
│           │             │ Amplitude:       │                 │
│           │             │ 0.2–0.5 mm       │                 │
│           │             └────────┬─────────┘                 │
│           │                      │                            │
│           └──────────┬───────────┘                            │
│                      ▼                                        │
│           ┌──────────────────┐                               │
│           │ Vital Signs      │                               │
│           │ Fusion           │──▶ VitalSignReport             │
│           │ (multi-link,     │                               │
│           │  multi-band)     │                               │
│           └──────────────────┘                               │
│                                                               │
│  Events emitted:                                             │
│    BreathingRateEstimated { bpm, confidence, method }         │
│    HeartRateEstimated { bpm, confidence, hrv_ms }             │
│    ApneaEventDetected { duration_s, severity }                │
│    DisplacementAnomaly { max_displacement_mm, location }      │
│                                                               │
└──────────────────────────────────────────────────────────────┘

Aggregates:

RespiratoryAnalyzer (Aggregate Root) — Extracts breathing rate and pattern from 0.1–0.6 Hz displacement band

Entities:

PhaseTimeSeries — Windowed buffer of unwrapped phase values per subcarrier per link, at sounding cadence
DisplacementTimeSeries — Converted from phase: δ(t) = λΔφ(t) / (4π), represents physical surface displacement in mm
VitalSignReport — Fused output containing breathing rate, heart rate, HRV, confidence scores, and anomaly flags

Value Objects:

PhaseUnwrapped — Continuous (unwrapped) phase in radians, free from 2π ambiguity
DisplacementSample — Single displacement value in mm with timestamp and confidence
BreathingRate — BPM value (6–36 range) with confidence score
HeartRate — BPM value (48–180 range) with confidence score and HRV interval
ApneaEvent — Duration, severity, and confidence of detected breathing cessation

Domain Services:

PhaseUnwrapper — Continuous phase unwrapping with outlier rejection; critical for displacement conversion
RespiratoryHarmonicCanceller — Removes breathing harmonics from cardiac band to isolate heartbeat signal
MultilinkFuser — Combines displacement estimates across node pairs using SNR-weighted averaging
AnomalyDetector — Flags displacement patterns inconsistent with normal physiology (fall, seizure, cardiac arrest)

Invariants:

Phase unwrapping must maintain continuity: |Δφ| < π between consecutive samples
Displacement floor must be validated against acceptance metric (AT-2: ≤ 0.1 mm at 2 m)
Heart rate estimation requires minimum 10 seconds of stable data (cardiac analyzer warmup)
Multi-link fusion must use ≥2 independent links for confidence scoring

6. Regulatory Compliance Context

Responsibility: Ensuring all CHCI transmissions comply with applicable ISM band regulations across deployment jurisdictions.

┌──────────────────────────────────────────────────────────────┐
│              Regulatory Compliance Context                    │
├──────────────────────────────────────────────────────────────┤
│                                                                │
│  ┌───────────────┐    ┌───────────────┐    ┌──────────────┐  │
│  │ FCC Part 15   │    │ ETSI EN       │    │ 802.11bf     │  │
│  │ Rules         │    │ 300 328       │    │ Compliance   │  │
│  │               │    │               │    │              │  │
│  │ - 30 dBm max  │    │ - 20 dBm EIRP│    │ - NDP format │  │
│  │ - Digital mod │    │ - LBT or 10ms │    │ - SAW window │  │
│  │ - Spread      │    │   burst max   │    │ - SMS setup  │  │
│  │   spectrum    │    │ - Duty cycle  │    │              │  │
│  └───────┬───────┘    └───────┬───────┘    └──────┬───────┘  │
│          │                    │                    │          │
│          └────────────┬───────┴────────────────────┘          │
│                       ▼                                       │
│            ┌──────────────────┐                               │
│            │ Compliance       │                               │
│            │ Validator        │                               │
│            │ (Aggregate Root) │                               │
│            │                  │                               │
│            │ Validates every  │                               │
│            │ WaveformConfig   │                               │
│            │ before TX        │                               │
│            └────────┬─────────┘                               │
│                     │                                         │
│                     ▼                                         │
│            ┌──────────────────┐                               │
│            │ Jurisdiction     │                               │
│            │ Registry         │                               │
│            │                  │                               │
│            │ US → FCC         │                               │
│            │ EU → ETSI        │                               │
│            │ JP → ARIB        │                               │
│            │ ...              │                               │
│            └──────────────────┘                               │
│                                                               │
│  Events emitted:                                             │
│    ComplianceCheckPassed { jurisdiction, config_hash }         │
│    ComplianceViolation { rule, parameter, value, limit }       │
│    JurisdictionChanged { from, to }                           │
│                                                               │
└──────────────────────────────────────────────────────────────┘

Aggregates:

ComplianceValidator (Aggregate Root) — Gate that must approve every waveform configuration before transmission is permitted

Entities:

JurisdictionProfile — Complete set of regulatory constraints for a given region (FCC, ETSI, ARIB, etc.)
ComplianceRecord — Audit trail of compliance checks with timestamps and configuration hashes

Value Objects:

MaxEIRP — Maximum effective isotropic radiated power in dBm, per band per jurisdiction
MaxBurstDuration — Maximum continuous transmission time (ETSI: 10 ms)
MinIdleTime — Minimum idle period between bursts
ModulationType — Must be digital modulation (OFDM qualifies) or spread spectrum for FCC
DutyCycleLimit — Maximum percentage of time occupied by transmissions

Invariants:

No transmission shall occur without a passing ComplianceCheckPassed event
Duty cycle must be recalculated and validated on every cadence change
Jurisdiction must be set during deployment configuration; default is most restrictive (ETSI)

Core Domain Entities

CoherentCsiFrame (Entity)

rust

pub struct CoherentCsiFrame {
    /// Unique sequence identifier for this sounding frame
    seq_id: u64,
    /// Node that received this frame
    rx_node_id: NodeId,
    /// Node that transmitted this frame (known from sounding schedule)
    tx_node_id: NodeId,
    /// Frequency band: Band2_4GHz, Band5GHz, Band6GHz
    band: FrequencyBand,
    /// UTC timestamp with microsecond precision
    timestamp_us: u64,
    /// Complex channel response per subcarrier: (amplitude, phase) pairs
    subcarrier_responses: Vec<Complex64>,
    /// Phase lock status at time of capture
    phase_lock: LockStatus,
    /// Residual phase offset from calibration (degrees)
    residual_offset_deg: f64,
    /// Signal-to-noise ratio estimate (dB)
    snr_db: f32,
    /// Sounding mode that produced this frame
    source_mode: SoundingMode,
}

Invariants:

phase_lock must be Locked for frame to be used in coherent processing
subcarrier_responses.len() must match expected count for band and bandwidth (56 for 20 MHz)
snr_db must be ≥ 10 dB for frame to contribute to displacement estimation
timestamp_us must be monotonically increasing per rx_node_id

WaveformConfig (Value Object)

rust

pub struct WaveformConfig {
    /// Active sensing mode
    mode: SensingMode,
    /// Sounding cadence in Hz
    cadence_hz: f64,
    /// Active frequency bands
    bands: BandSet,
    /// Bandwidth per band
    bandwidth_mhz: u8,
    /// Transmit power in dBm
    tx_power_dbm: f32,
    /// Subcarrier mask (None = all subcarriers active)
    subcarrier_mask: Option<BitVec>,
    /// Burst duration in microseconds
    burst_duration_us: u16,
    /// Number of symbols per burst
    symbols_per_burst: u8,
    /// Computed duty cycle (must pass compliance check)
    duty_cycle_pct: f64,
}

Invariants:

cadence_hz must be ≥ 1.0 and ≤ 5000.0
duty_cycle_pct must not exceed jurisdiction limit (ETSI: derived from 10 ms burst max)
tx_power_dbm must not exceed jurisdiction max EIRP
bandwidth_mhz must be one of {20, 40, 80}
burst_duration_us must be ≥ 4 (single OFDM symbol + CP)

SensingMode (Value Object)

rust

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum SensingMode {
    /// 1 Hz, single band, presence detection only
    Idle,
    /// 10 Hz, dual band, coarse tracking
    Alert,
    /// 50-200 Hz, all bands, full DensePose + vitals
    Active,
    /// 100 Hz, optimal subcarrier subset, breathing + HR + HRV
    Vital,
    /// 200 Hz, full band, DTW gesture classification
    Gesture,
    /// 20 Hz, single band, apnea/movement/stage detection
    Sleep,
}

impl SensingMode {
    pub fn default_config(&self) -> WaveformConfig {
        match self {
            Self::Idle => WaveformConfig {
                mode: *self,
                cadence_hz: 1.0,
                bands: BandSet::single(Band::Band2_4GHz),
                bandwidth_mhz: 20,
                tx_power_dbm: 10.0,
                subcarrier_mask: None,
                burst_duration_us: 4,
                symbols_per_burst: 1,
                duty_cycle_pct: 0.0004,
            },
            Self::Alert => WaveformConfig {
                mode: *self,
                cadence_hz: 10.0,
                bands: BandSet::dual(Band::Band2_4GHz, Band::Band5GHz),
                bandwidth_mhz: 20,
                tx_power_dbm: 15.0,
                subcarrier_mask: None,
                burst_duration_us: 8,
                symbols_per_burst: 2,
                duty_cycle_pct: 0.008,
            },
            Self::Active => WaveformConfig {
                mode: *self,
                cadence_hz: 100.0,
                bands: BandSet::all(),
                bandwidth_mhz: 40,
                tx_power_dbm: 20.0,
                subcarrier_mask: None,
                burst_duration_us: 16,
                symbols_per_burst: 4,
                duty_cycle_pct: 0.16,
            },
            Self::Vital => WaveformConfig {
                mode: *self,
                cadence_hz: 100.0,
                bands: BandSet::dual(Band::Band2_4GHz, Band::Band5GHz),
                bandwidth_mhz: 20,
                tx_power_dbm: 18.0,
                subcarrier_mask: Some(optimal_vital_subcarriers()),
                burst_duration_us: 8,
                symbols_per_burst: 2,
                duty_cycle_pct: 0.08,
            },
            Self::Gesture => WaveformConfig {
                mode: *self,
                cadence_hz: 200.0,
                bands: BandSet::all(),
                bandwidth_mhz: 40,
                tx_power_dbm: 20.0,
                subcarrier_mask: None,
                burst_duration_us: 16,
                symbols_per_burst: 4,
                duty_cycle_pct: 0.32,
            },
            Self::Sleep => WaveformConfig {
                mode: *self,
                cadence_hz: 20.0,
                bands: BandSet::single(Band::Band2_4GHz),
                bandwidth_mhz: 20,
                tx_power_dbm: 12.0,
                subcarrier_mask: None,
                burst_duration_us: 4,
                symbols_per_burst: 1,
                duty_cycle_pct: 0.008,
            },
        }
    }
}

VitalSignReport (Value Object)

rust

pub struct VitalSignReport {
    /// Timestamp of this report
    timestamp_us: u64,
    /// Breathing rate in BPM (None if not measurable)
    breathing_bpm: Option<f64>,
    /// Breathing confidence [0.0, 1.0]
    breathing_confidence: f64,
    /// Heart rate in BPM (None if not measurable — requires CHCI coherent mode)
    heart_rate_bpm: Option<f64>,
    /// Heart rate confidence [0.0, 1.0]
    heart_rate_confidence: f64,
    /// Heart rate variability: RMSSD in milliseconds
    hrv_rmssd_ms: Option<f64>,
    /// Detected anomalies
    anomalies: Vec<VitalAnomaly>,
    /// Number of independent links contributing to this estimate
    contributing_links: u16,
    /// Sensing mode that produced this report
    source_mode: SensingMode,
}

pub enum VitalAnomaly {
    Apnea { duration_s: f64, severity: Severity },
    Tachycardia { bpm: f64 },
    Bradycardia { bpm: f64 },
    IrregularRhythm { irregularity_score: f64 },
    FallDetected { impact_g: f64 },
    NoMotion { duration_s: f64 },
}

NodeId and FrequencyBand (Value Objects)

rust

/// Unique identifier for a CHCI node in the sensing mesh
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct NodeId(pub u8);

/// Operating frequency band
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum FrequencyBand {
    /// 2.4 GHz ISM band (2400-2483.5 MHz), λ = 12.5 cm
    Band2_4GHz,
    /// 5 GHz UNII band (5150-5850 MHz), λ = 6.0 cm
    Band5GHz,
    /// 6 GHz band (5925-7125 MHz), λ = 5.0 cm, WiFi 6E
    Band6GHz,
}

impl FrequencyBand {
    pub fn wavelength_m(&self) -> f64 {
        match self {
            Self::Band2_4GHz => 0.125,
            Self::Band5GHz => 0.060,
            Self::Band6GHz => 0.050,
        }
    }

    /// Displacement per radian of phase change: λ/(4π)
    pub fn displacement_per_radian_mm(&self) -> f64 {
        self.wavelength_m() * 1000.0 / (4.0 * std::f64::consts::PI)
    }
}

Domain Events

Waveform Events

rust

pub enum WaveformEvent {
    /// A sounding frame was transmitted
    SoundingFrameTransmitted {
        seq_id: u64,
        tx_node: NodeId,
        band: FrequencyBand,
        timestamp_us: u64,
    },
    /// A burst sequence completed (micro-burst mode)
    BurstSequenceCompleted {
        burst_count: u32,
        total_duration_us: u64,
    },
    /// Waveform configuration changed (mode transition)
    WaveformConfigChanged {
        old_mode: SensingMode,
        new_mode: SensingMode,
        trigger: ModeTransitionTrigger,
    },
}

pub enum ModeTransitionTrigger {
    CoherenceDeltaThreshold { delta: f64 },
    PersonDetected { confidence: f64 },
    PersonLost { absence_duration_s: f64 },
    PoseClassification { pose: PoseClass },
    MotionSpike { magnitude: f64 },
    Manual,
}

Clock Events

rust

pub enum ClockEvent {
    /// A node achieved phase lock
    ClockLockAcquired {
        node_id: NodeId,
        residual_offset_deg: f64,
    },
    /// Phase drift detected on a node
    PhaseDriftDetected {
        node_id: NodeId,
        drift_deg_per_min: f64,
    },
    /// Phase lock lost on a node — triggers fallback to statistical correction
    ClockLockLost {
        node_id: NodeId,
        reason: LockLossReason,
    },
    /// Calibration procedure completed
    CalibrationCompleted {
        residual_offsets: Vec<(NodeId, f64)>,
        max_residual_deg: f64,
    },
}

Measurement Events

rust

pub enum MeasurementEvent {
    /// Body surface reconstructed from diffraction tomography
    BodySurfaceReconstructed {
        n_vertices: u32,
        resolution_cm: f64,
        confidence: f64,
        timestamp_us: u64,
    },
    /// Vital signs estimated
    VitalSignsUpdated {
        report: VitalSignReport,
    },
    /// Displacement anomaly detected
    DisplacementAnomaly {
        max_displacement_mm: f64,
        anomaly_type: VitalAnomaly,
    },
    /// Coherence degradation on a link (may trigger recalibration)
    CoherenceDegradation {
        tx_node: NodeId,
        rx_node: NodeId,
        band: FrequencyBand,
        severity: Severity,
    },
}

Context Map

┌─────────────────────────────────────────────────────────────────────────┐
│                         CHCI Context Map                                │
│                                                                         │
│  ┌────────────────┐         ┌────────────────┐                         │
│  │   Waveform     │ ◀─────  │   Cognitive    │                         │
│  │   Generation   │ config  │   Waveform     │                         │
│  │   Context      │         │   Context      │                         │
│  └───────┬────────┘         └───────▲────────┘                         │
│          │                          │                                   │
│          │ sounding                 │ scene state                       │
│          │ frames                   │ feedback                          │
│          ▼                          │                                   │
│  ┌────────────────┐         ┌───────┴────────┐                         │
│  │   Clock        │ phase   │   Coherent     │                         │
│  │   Synchro-     │ lock ──▶│   Signal       │                         │
│  │   nization     │ status  │   Processing   │                         │
│  │   Context      │         │   Context      │                         │
│  └────────────────┘         └───────┬────────┘                         │
│                                     │                                   │
│                              body surface,                              │
│                              coherence metrics                          │
│                                     │                                   │
│                                     ▼                                   │
│                             ┌────────────────┐                         │
│                             │  Displacement   │                         │
│                             │  Measurement    │                         │
│                             │  Context        │                         │
│                             └────────────────┘                         │
│                                                                         │
│  ┌────────────────┐                                                    │
│  │  Regulatory    │ ◀── validates all WaveformConfig before TX         │
│  │  Compliance    │                                                    │
│  │  Context       │                                                    │
│  └────────────────┘                                                    │
│                                                                         │
│  ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─       │
│  Integration with existing WiFi-DensePose bounded contexts:             │
│                                                                         │
│  ┌────────────────┐    ┌────────────────┐    ┌────────────────┐       │
│  │  RuvSense      │    │  RuVector      │    │  DensePose     │       │
│  │  Multistatic   │    │  Cross-View    │    │  Body Model    │       │
│  │  (ADR-029)     │    │  Fusion        │    │  (Core)        │       │
│  └────────────────┘    └────────────────┘    └────────────────┘       │
│                                                                         │
│  CHCI Signal Processing feeds directly into existing                   │
│  RuvSense/RuVector/DensePose pipeline — coherent CSI                   │
│  replaces incoherent CSI as input, same output interface               │
│                                                                         │
└─────────────────────────────────────────────────────────────────────────┘

Anti-Corruption Layers

Boundary	Direction	Mechanism
CHCI Signal Processing → RuvSense	Downstream	`CoherentCsiFrame` adapts to existing `CsiFrame` trait via `IntoLegacyCsi` adapter — existing pipeline works unmodified
Cognitive Waveform → ADR-039 Edge Tiers	Bidirectional	Sensing modes map to edge tiers: IDLE→Tier0, ACTIVE→Tier1, VITAL→Tier2. Shared `EdgeConfig` value object
Clock Synchronization → Hardware	Downstream	`ClockDriver` trait abstracts SI5351A hardware specifics; mock implementation for testing
Regulatory Compliance → All TX Contexts	Upstream	Compliance Validator acts as a policy gateway — no transmission without passing check

Integration with Existing Codebase

Modified Modules

File	Current	CHCI Change
`signal/src/ruvsense/phase_align.rs`	Statistical LO offset estimation via circular mean	Add `SharedClockAligner` path: when `phase_lock == Locked`, skip statistical estimation, apply only residual calibration offset
`signal/src/ruvsense/multiband.rs`	Independent per-channel fusion	Add `CoherentCrossBandFuser`: phase-aligns across bands using body model priors before fusion
`signal/src/ruvsense/coherence.rs`	Z-score coherence scoring (real-valued)	Add `ComplexCoherenceMetric`: phasor-domain coherence using both magnitude and phase information
`signal/src/ruvsense/tomography.rs`	Amplitude-only ISTA L1 solver	Add `DiffractionTomographyEngine`: complex-valued reconstruction using channel contrast
`signal/src/ruvsense/coherence_gate.rs`	Accept/Reject gate decisions	Add cognitive waveform feedback: gate decisions emit `CoherenceDelta` events to mode state machine
`signal/src/ruvsense/multistatic.rs`	Attention-weighted fusion	Add clock synchronization status as fusion weight modifier
`hardware/src/esp32/`	TDM protocol, channel hopping	Add NDP sounding mode, reference clock driver, phase reference input
`ruvector/src/viewpoint/attention.rs`	CrossViewpointAttention	Extend to cross-band attention with frequency-dependent geometric bias

New Crate: `wifi-densepose-chci`

wifi-densepose-chci/
├── src/
│   ├── lib.rs                    # Crate root, re-exports
│   ├── waveform/
│   │   ├── mod.rs
│   │   ├── ndp_generator.rs      # 802.11bf NDP sounding frame generation
│   │   ├── burst_generator.rs    # Micro-burst OFDM symbol generation
│   │   ├── scheduler.rs          # Sounding schedule orchestration
│   │   └── compliance.rs         # Regulatory compliance validation
│   ├── clock/
│   │   ├── mod.rs
│   │   ├── reference.rs          # Reference clock module abstraction
│   │   ├── pll_driver.rs         # SI5351A PLL synthesizer driver
│   │   ├── calibration.rs        # Phase calibration procedures
│   │   └── drift_monitor.rs      # Continuous drift detection
│   ├── cognitive/
│   │   ├── mod.rs
│   │   ├── mode.rs               # SensingMode enum and transitions
│   │   ├── state_machine.rs      # Mode state machine with hysteresis
│   │   ├── scene_observer.rs     # Scene state fusion from body model + coherence
│   │   ├── subcarrier_select.rs  # Optimal subcarrier subset for vital mode
│   │   └── power_manager.rs      # Power budget per mode
│   ├── tomography/
│   │   ├── mod.rs
│   │   ├── contrast.rs           # Channel contrast computation
│   │   ├── diffraction.rs        # Coherent diffraction tomography engine
│   │   └── surface.rs            # Iso-surface extraction (marching cubes)
│   ├── displacement/
│   │   ├── mod.rs
│   │   ├── phase_to_disp.rs      # Phase-to-displacement conversion
│   │   ├── respiratory.rs        # Breathing rate analyzer
│   │   ├── cardiac.rs            # Heart rate + HRV analyzer
│   │   └── anomaly.rs            # Vital sign anomaly detection
│   └── types.rs                  # Shared types (NodeId, FrequencyBand, etc.)
├── Cargo.toml
└── tests/
    ├── integration/
    │   ├── acceptance_tests.rs   # AT-1 through AT-8
    │   └── mode_transitions.rs   # Cognitive state machine tests
    └── unit/
        ├── compliance_tests.rs
        ├── displacement_tests.rs
        └── tomography_tests.rs

Coherent Human Channel Imaging (CHCI) Domain Model

Coherent Human Channel Imaging (CHCI) Domain Model

Domain-Driven Design Specification

Ubiquitous Language

Bounded Contexts

1. Waveform Generation Context

2. Clock Synchronization Context

3. Coherent Signal Processing Context

4. Cognitive Waveform Context

5. Displacement Measurement Context

6. Regulatory Compliance Context

Core Domain Entities

CoherentCsiFrame (Entity)

WaveformConfig (Value Object)

SensingMode (Value Object)

VitalSignReport (Value Object)

NodeId and FrequencyBand (Value Objects)

Domain Events

Waveform Events

Clock Events

Measurement Events

Context Map

Anti-Corruption Layers

Integration with Existing Codebase

Modified Modules

New Crate: wifi-densepose-chci

New Crate: `wifi-densepose-chci`